Browse Topic: Side impact crashes

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A Comparative Life Cycle Assessment of Magnesium Front End Autoparts: A Revision to 2010-01-0275SAE-PP-001851/29/2021
The Magnesium Front End Research and Development (MFERD) project under the sponsorship of Canada, China, and USA aims to develop key technologies and a knowledge base for increased use of magnesium in automobiles. The primary goal of this life cycle assessment (LCA) study is to compare the energy and potential environmental impacts of advanced magnesium based front end parts of a North American-built 2007 GM-Cadillac CTS using the current steel structure as a baseline. An aluminium front end is also considered as an alternate light structure scenario. A “cradle-to-grave” LCA is conducted by including primary material production, semi-fabrication production, autoparts manufacturing and assembly, transportation, use phase, and end-of-life processing of autoparts. This LCA study was done in compliance with international standards ISO 14040:2006 [1] and ISO 14044:2006 [2]. While weight savings result in reductions of energy use and climate change emissions during the use phase of the car, the impacts of autoparts manufacturing and end of life recycling phases of lightweight autoparts designs are substantial as well. Pathways for improving sustainability of magnesium use in automobiles through material management and technology improvements including recycling are also discussed. Mg lightweight designs contribute to the largest use phase total primary and climate change savings over the vehicle's life time. Sustainably manufactured and recycled large magnesium structural parts can provide environmental benefits in terms of climate change emissions and consequently energy use vis-à-vis steel within the expected life of the vehicle. Overall, the aluminum lightweight design showed the best breakeven vehicle distance travelled from primary energy use and climate change perspectives within the vehicle's life time.
Mutagaana, Festo
Innovative Active Head Restraint System in a Car: Safety Assessment with Virtual Human Body Model2020-01-09794/14/2020
The aim of this study is to use numerical simulations for safety assessment of an innovative active head restraint system. This system was developed to protect the head and neck of an occupant in a car without a head airbag during a side impact. Its FE model is created and embedded it in a model of a small car with a side airbag. The dynamics of the head restraint activation are also taken into account. The virtual human body model Virthuman is used to represent occupants. The model is scaled for pre-selected human individuals to cover large numbers of occupants of different sizes. It extends conventional virtual evaluation of new safety designs via existing pre-defined mono-purpose side dummies and their FE models. The benefit of the head restraint system is evaluated in side impact scenarios inspired by the pole tests performed by EuroNCAP. Transversal impacts to a pole at 29 and 32 km/h are considered at 90° and 75° angles from driver and the opposite side. Also, the far side impact prescribed with an acceleration pulse according to EuroNCAP is considered. Various initial driver sizes in standard seated positions are tested. To extend the study beyond standard testing protocols, out-of-position of driver is also considered, leading to more than 100 simulations of impact scenarios in total. The effect of the innovative head restraint system is assessed from the point of view of driver injury risk.
Vychytil, Jan, Hlucha, Jana, Kovar, Ludek, Kostikova, Martina, Moravcova, Pavlina, Bucsuhazy, Katerina
Likelihood of Spinal Disc Herniations in Occupants Involved in Real World Side Impacts2020-01-05264/14/2020
The prevalence of spinal disc herniations in people with no spinal symptoms have been reported to increase with age; from about 20% in those below 40 years to about 30% in those above 40 years. Spinal disc herniations are usually associated with degenerative changes. Though rare, spinal disc herniations can also be caused by trauma. With an increasing number of older people on U.S. roads with a concomitant increase in the probability of getting injured in a vehicle collision, it is reasonable to expect that some of these occupants can present with clinical findings of spinal disc herniations after a side impact, and attribute these findings to the impact. In this study, we looked at the relationship between real world side impacts and the occurrence of spinal injuries, in particular disc herniations, in occupants involved in such impacts. We examined the reported occurrence of all spine injuries in side impact crashes in the National Automotive Sampling System - Crashworthiness Data System (NASS-CDS) database from 1993 through 2014. There were over 8,400 adult raw case occupants, corresponding to a weighted number of approximately 4.7 million that fit the inclusion criteria. The results showed that the most common spine injury in side impact is acute muscle strain of the cervical spine, followed by acute muscle strain of the lumbar spine. The total number of occupants with reported spinal disc herniations was only three; all from near-side impacts. The low prevalence of reported spinal disc herniations stands in sharp contrast to a background prevalence of 20% to 30% in asymptomatic individuals. The findings from the real world data in this study, in light of known spinal responses in experiments conducted on post-mortem human subjects (PMHSs) and anthropomorphic test devices (ATDs) exposed to near- and far-side impacts, suggest that side impacts do not present a mechanism of traumatic disc herniation.
Lam, Tack, Ivarsson, B. Johan
Automated Driving System Data LoggerJ3197_202004 (Historical)4/11/2020
This recommended practice provides common data output formats and definitions for a variety of data elements that may be useful for analyzing the performance of automated driving system (ADS) during an event that meets the trigger threshold criteria specified in this document. The document is intended to govern data element definitions, to provide a minimum data element set, and to specify a common ADS data logger record format as applicable for motor vehicle applications. The data elements defined in this document are unique to Levels 3, 4, or 5 ADS features, as defined by SAE J3016, and provide additional background of the events leading up to a crash or crash-like event. The data from sensors such as camera(s), LiDAR(s) etc. will provide information in the absence of a human driver. The data included in the ADS data logger is expected to be used in conjunction with the SAE J1698 EDR record and traditional accident reconstruction analysis. The event data recorder (EDR) and ADS data logger will capture information leading up to the triggered event, at a minimum. ADS technology is still being developed and is not yet commercially deployed. Therefore, this SAE Recommended Practice is intended as a guide toward standard practice and is subject to change to keep pace with experience and technical advances.
Event Data Recorder Committee
Investigating Combined Thoracic Loading Using the Elderly Female Dummy (EFD)2019-22-00173/31/2020
The Elderly Female Dummy (EFD) is an omni-directional ATD developed to represent a vulnerable population. The EFD it is able to be 3D printed and quickly altered to meet design requirements. A recent side impact sled test series suggested that small, elderly females may be at risk of thoracic injuries in side impact crashes due to combined loading from the belt pre-tensioner and side airbag. The EFD was altered to add four IR-TRACCs to the thoracic region to allow both x-axis and y-axis displacement to be evaluated in a similar test. While the IR-TRACCs did record the displacement due to combined loading, the rate of displacement and timing of the peak displacements did not match external chestband outputs. The next step for the EFD is to revise the locations of IRTRACCs in the thorax and begin component testing in lateral and frontal directions to improve thoracic biofidelity.
Beebe, Michael, Sullenberger, Kris, Burleigh, Mark, McCarthy, Joe, Bolte IV, John H
Message Sets for Advanced Traveler Information System (ATIS)J2354_201906 (Current)6/11/2019
This SAE Standard describes standardized medium-independent messages needed by information service providers for Advanced Traveler Information Systems (ATIS). The messages contained herein address all stages of travel (informational, pre-trip and en route), all types of travelers (drivers, passengers, personal devices, computers, other servers), all categories of information, and all platforms for delivery of information (in-vehicle, portable devices, kiosks, etc.).
V2X Core Technical Committee
Performance of Event Data Recorders Found in Toyota Airbag Control Modules in High Severity Frontal Oblique Offset Crash Tests2019-01-06334/2/2019
This paper presents an in-depth analysis of the performance of Event Data Recorders (EDRs) found in the Airbag Control Modules (ACMs), as tested in support of the National Highway Traffic Safety Administration’s Frontal Oblique Offset Program. Previous studies have examined EDR performance in high severity full-frontal barrier crash tests and moving deformable barrier side impact tests. This paper presents data from a high severity oblique frontal impact test in which the vehicle was struck by a moving deformable barrier. This paper examines the results of EDR data downloaded from two 2015 model year Toyota Highlanders, and the results of EDR reported change in velocity (delta-v), to vehicle mounted accelerometers and reference instrumentation. This paper will analyze EDR performance in reporting: Seatbelt buckle status, Occupant Size Classification, Front Passenger, Airbag and seatbelt pretensioner deployment time(s), Longitudinal delta-v, and Lateral acceleration/crash pulse.
Bortles, William, Hostetler, Ryan
Passenger Vehicle Dynamic Response and Characterization of Side Structure during Low- to Moderate-Speed Side Impacts2019-01-04204/2/2019
A significant portion of real-world passenger vehicle side impacts occur at lower speeds than testing conducted by the National Highway Traffic Safety Administration (NHTSA) or the Insurance Institute for Highway Safety (IIHS). Test data from low- to moderate-speed side impacts involving late-model passenger vehicles is limited, making the evaluation of vehicle impact response, occupant loading, and injury potential challenging. This study provides the results of low- to moderate-speed impact testing involving a late-model mid-size sedan. Two full-scale Non-Deformable Moving Barrier (NDMB) side impact crash tests were conducted at speeds of 6.2 mph (10.0 kph) and 13.4 mph (21.6 kph). Instrumentation on the late-model sedan used for the test series included tri-axis accelerometers and seat belt load cells. In both tests, instrumented Hybrid III 50th percentile-male Anthropomorphic Test Devices (ATDs) were restrained in the driver and passenger seats using the standard three-point seat belts. Response data for the vehicle, barrier, and ATDs was recorded using onboard data acquisition, and on- and off-board real-time and high-speed video cameras. In addition, the deformation to the side of the sedan was quantified from pre- and post-test laser scan data. Results from the test series provided data regarding accelerations, velocity change, and restitution. The damage to the side structure of the vehicle was assessed and conclusions regarding damage initiation and damage progression are discussed. Conservation of Momentum and Conservation of Energy analyses are presented and force-displacement characteristics and energy dissipation were evaluated and compared. Utilizing the data that was developed from the test series, vehicle side stiffness modeling was also conducted.
Skiera, Jason, Crosby, Charles, Bare, Cleve, Paradiso, Marc, Campbell, Gregory
The Kinematic Analysis of Occupant Excursions and Accelerations during Staged Low Speed Far-Side Lateral Vehicle-to-Vehicle Impacts2019-01-10304/2/2019
The collection of research regarding occupant kinematics during low speed lateral vehicle-to-vehicle impacts is far less comprehensive than the much larger body of literature that quantifies the occupant kinematics associated with low speed rear end (longitudinal) impacts. In order to augment the available data, a series of 39 low speed far-side lateral vehicle-to-vehicle impacts were conducted in a laboratory setting. A combination of accelerometers and 3D motion tracking was used to characterize the motions of both the Target and Bullet vehicles during their collisions. The Target vehicle was initially stationary; the Bullet vehicle impacted the Target vehicle at the front passenger side door. The Bullet vehicle pre-impact speeds across all tests ranged from approximately 2.5 to 5.5 mph (4.0 to 8.9 kph; 1.1 to 2.5 m/s). Eight volunteers participated in the study. Volunteers were seated in the driver seat during the impacts and were outfitted with accelerometers on their head and wore reflective markers for 3D motion tracking on the left side of their body. The experimental design included conducting lateral impacts while the volunteers were in both “non-distracted” and “distracted” states to identify any potential influence on occupant kinematics. In addition, effects of gender and anthropometry were explored. Primary outcome measures that were analyzed for each lateral impact included occupant accelerations measured at the head and the lateral displacement of the head relative to its initial position prior to impact. Volunteer peak resultant head accelerations (including gravity) ranged from 1.90 to 4.32 g. The peak Y-axis displacement of the head relative to the Target vehicle and away from the driver side B-pillar was 3.86 to 12.16 inches (9.80 to 30.89 cm) while the peak Y-axis displacement of the head relative to the Target vehicle and toward the driver side B-pillar ranged from 0.02 to 7.34 inches (0.05 to 18.64 cm). In all trials, the head displacement toward the driver side B-pillar was insufficient to cause physical contact.
Shibata, Peggy, Roberts, Julius, Sprague, James, Light, Alyson, Stegemann, Jacob, Meza-Arroyo, Manuel, Capser, Shawn
Comparative Responses of the PIPER 6YO Human Body Model and the Q6 ATD for Simulated Frontal and Lateral ImpactsSC18-22-000611/12/2018
Abstract - Adult and pediatric human body models have focused on developing accurate representation of the human body in terms of anthropometry and kinetics/kinematics in correlation with published PMHS (Post-Mortem Human Subjects) data. This study focuses on comparing the PIPER 6-year-old human body finite element (FE) model with a Q6 FE model to generate comparable metrics. The FE models were simulated in a vehicle environment by positioning them on two different child booster seats with a 3-point lap-shoulder belt for frontal and lateral impacts. The overall kinematic response (head excursion) of the PIPER human body model (HBM) mimics the behavior of the Q6 ATD. However, there is a significant difference in the NIJ values between the PIPER HBM and Q6 ATD (minimum reduction of 67% in PIPER HBM). The head-neck complex of the PIPER is seen to be more flexible (minimum reduction of 12% in neck forces and 64% in neck moments) as compared to the Q6.
Sarfare, Shreyas, Maheshwari, Jalaj, Duong, Nhat, Belwadi, Aditya
Validation of Crush Energy Calculation Methods for Use in Accident Reconstructions by Finite Element Analysis09-06-02-000910/4/2018
The crush energy is a key parameter to determine the delta-V in accident reconstructions. Since an accurate car crush profile can be obtained from 3D scanners, this research aims at validating the methods currently used in calculating crush energy from a crush profile. For this validation, a finite element (FE) car model was analyzed using various types of impact conditions to investigate the theory of energy-based accident reconstruction. Two methods exist to calculate the crush energy: the work based on the barrier force and the work based on force calculated by the vehicle acceleration times the vehicle mass. We show that the crush energy calculated from the barrier force was substantially larger than the internal energy calculated from the FE model. Whereas the crush energy calculated from the vehicle acceleration was comparable to the internal energy of the FE model. In full frontal impact simulations, the energy of approach factor (EAF) has a linear relation with the residual crush, which had been validated in previous experimental studies. In our study using FE analysis, we found that the slope of EAF versus the residual crush was comparable with that of the dynamic crush energy versus the dynamic crush for crashes at 55 km/h. Using this slope and the residual crush from a 55 km/h impact test, the slope and the intercept of the EAF vs. residual crush can be determined using only one crash test. A database of the slopes and the intercepts was made using Japan New Car Assessment Program (JNCAP) tests. In offset impact simulations, the crush energy calculated from the crush profile agreed with the internal energy of the car FE model when at least one front rail was involved. In oblique impacts, the correction factor for crush energy is not necessary within 20 degrees of principal direction of force of the car’s longitudinal axis.
Numata, Shusuke, Mizuno, Koji, Ito, Daisuke, Okumura, Dai
Autonomous vehicles present passive-safety challenges18AUTP10_0810/1/2018
Reclined and rotated seating positions are commonly depicted for autonomously driven vehicles. But for the Autoliv engineers tasked with developing occupant safety for tomorrow's self-driving vehicles, those previously improbable seating positions dictate innovative new passive safety protections. “Passive safety for autonomous vehicles is a pretty complicated problem to solve, which is why we're starting out with the simplest scenario: a frontal crash with a front occupant in a partial-recline position,” E. Scott Dershem, Autoliv's Vice President of Product Development, said in an interview with Automotive Engineering at the safety supplier's Auburn Hills, Michigan technical center.
Buchholz, Kami
Torsional Fluctuations Consideration while Design of Synchro Rings2018-01-18239/10/2018
In today’s manual transmissions of car, gearshift system requires high performance with particular emphasis on low effort, minimal travel and positive feel. To meet these targets, a high capacity multi cone synchronizers along with higher co-efficient of friction material used for lower gears. The design of synchronizer with these specifications is influenced by torsional fluctuations from engine. Excessive torsional vibrations leads to wobbling of synchro rings within the peripheral clearances with surrounding parts. Wobbling leads to abrasion wear of frictional area of synchro ring causing grating or crashing noise of gears during shifting. This paper presents the optimization of the multiple cone synchronizer design exposed to excessive torsional vibrations and validation of the same on test bench during development stage instead vehicle level validation.
Tawhare, Nitin, Aswale, Dhananjay, Ponkshe, Makarand
Predictive Estimation of Side Pole Impact Dummy Response Based on Linear Impactor SAB Performance2018-01-50186/18/2018
This article discusses steps to predictively estimate the responses of Anthropomorphic Test Device (ATD) in a side impact event, based on a Side Airbag (SAB) Force-Deformation (F-D) characteristics derived from the linear impactor test. A critical load management challenge that has been used to assess this predictive response process is the oblique pole impact test - part of the FMVSS 214 protocol. In this scenario, the ATD is assumed to have a free travel until it is stopped by the crushed and stacked up door against the rigid pole. Three critical energy management paths involved to manage the kinetic energy of the ATD at impact are assumed at the onset, namely, the door trim crush, ATD torso loading and most important efficient energy management of the SAB at a controlled force level. The SAB energy management is assumed critical and tied with the final response of the test ATD. In the study being reported, the amount of energy absorbed by the SAB and the reaction force of the SAB are used to predictively estimate the final responses of the test ATD. After robust vehicle components and systems designs for body structure, door trim, friendly interior and effective SAB to ATD coverage are achieved, results from this study show that the F-D response of the SAB is crucial and may be used to predictively estimate the final response of the test ATD. The ability to predictively estimate ATD responses via linear impactor derived SAB F-D at the component level will invariably greatly reduce SAB development time and overall side impact safety development cost. Examples of physical SAB linear impactor test results have been used to demonstrate the effectiveness of this predictive assessment tool in terms of SAB development time.
Uduma, Kalu, Purushothaman, Dipu, Wu, Jianping, Beaudet, Brian, Keshtkar, Hamid
Modeling the Effect of Foam Density and Strain Rate on the Compressive Response of Polyurethane Foams05-11-02-00145/8/2018
Due to the high deformability and energy dissipation capacity of polymer foams in compression, they are used in automotive applications to mitigate mechanical impacts. The mechanical response of the foams is strongly affected by their density. Phenomenological relations have been proposed to describe the effect of foam density on their stress-strain response in compression at a fixed loading rate and the effect of loading rate at a fixed foam density. In the present work, these empirical approaches are combined allowing for the dependence of loading rate effect in compression on foam density. The minimum experimental data set for calibration of the proposed model consists of compression test results at two different loading rates of foams with two different densities. Rigid closed-cell polyurethane foams with apparent density in the range of ca. 100 to 300 kg/m3 have been produced and tested in compression up to a ca. 80% engineering strain at low (0.00167 to 0.5 s−1) and intermediate (~102 s−1) strain rates. The model parameters were evaluated from test results of the largest and smallest-density foams at low loading rates, differing by two orders of magnitude. The relative root mean square error of stress prediction for intermediate foam densities was found to range from ca. 6 to 12% at low strain rates and reach up to 34% at the higher strain rate. The proposed approach for modeling of foam behavior is expected to be useful in preliminary design of structural parts with impact mitigation functionality.
Japins, Guntis, Kalnins, Kaspars, Kirpluks, Mikelis, Cabulis, Ugis
Influence of Driver Position and Seat Design on Thoracolumbar Loading During Frontal Impacts2018-01-05444/3/2018
Previous research has detailed contributing factors to thoracolumbar compression fracture injury risk during frontal impacts in motorsport drivers utilizing a nearly recumbent driving position (Katsuhara, Takahira, Hayashi, Kitagawa, & Yasuki, 2017; Trammell, Weaver, & Bock, 2006; Troxel, Melvin, Begeman, & Grimm, 2006). This type of injury is very rare for upright seated motorsport drivers. While numerous improvements have been made to the driver restraint system used in the National Association for Stock Car Auto Racing, Incorporated (NASCAR®) since 2000, two instances of lumbar compression fractures have occurred during frontal impacts. Through the use of computation modeling, this study explores the influence of initial driver position and seat ramp design on thoracolumbar loading during frontal impacts. Quasi-static component testing, dynamic component testing, an instrumented driver fit check, a seat ramp angle survey, and sled testing were conducted to provide computational finite element (FE) model inputs and serve as validation tests. Upright magnetic resonance imaging (MRI) was conducted with a driver to visualize vertebral body locations with respect to the driver seat. FE modeling was conducted with the 50th percentile male Hybrid III FE model (Humanetics, Plymouth, MI) to validate a motorsport restraint system model. Sprague and Geers analysis was used to quantify and identify the optimally tuned FE model parameters. A 3-factor latin hypercube (LHD) sample space was created for acceleration magnitude and the principal direction of force (PDOF) about the Z-axis and about the Y-axis across 20 simulations. The Toyota Total Human Model for Safety (THUMS) was then used in four unique seat ramp angles in both slouched and upright postures, for a total of eight THUMS seated configurations. All eight configurations were subjected to the 20 variable values of the LHD sample space for a total of 160 simulations. A FE motorsport restraint system model was developed and validated against empirical component and sled test data. The THUMS was used in the validated motorsport restraint system. As seat ramp angles (SRA) increased, peak axial compressive force of T12, L1 and L2 decreased. For each SRA, the slouched THUMS initial position (TIP), which positioned the ischial tuberosities closer to the seat ramp, produced lower peak axial compressive forces. The peak XY resultant bending moment of T12 and L1 also decreased as SRA increased.
Patalak, John, Davis, Matthew, Gaewsky, James, Stitzel, Joel, Harper, Matthew
Effect of Hinge Axis Inclination and Hinge Tolerance on Door Strength under Abuse Loads2018-01-04804/3/2018
As revealed from J. D. Power surveys, today most vehicle owners consider perceived quality as a direct indicator of the vehicle build quality and durability. [5] The problem has become more prominent and noticeable in recent times, due to the desire for reduced cost, reduced weight targets, aesthetic demands, and crash requirements. The performance of the door assembly when subjected to an abuse load of sag and over opening is one such perceived quality indicator which gives the customer the first impression about the engineering and build quality of the vehicle. Door hinge inclination and hinge contact flushness tolerance are the major design parameters affecting this performance. Although these are an important design parameter, the precise quantification of the effect of these design parameters on door performance under abuse loading has remained somewhat elusive. Traditionally, this assessment was done using physical testing, thumb rules and best practices rather than using computer aided techniques. However with the automotive industry moving towards higher durability targets, reduced product cycle time and lower design costs, the need for virtual simulation has increased. The scope of this paper includes, study of load distribution on the top and bottom hinge pair of the door under over opening abuse load due to hinge contact flushness tolerance and the effect of change in door axis inclination on the door performance under door sag abuse loading. The Finite Element Modelling (FEM) techniques, boundary conditions and the interpretation of the changes in design parameters on the door assembly performance under sag and over opening loading are detailed in the subsequent discussion.
Bhagate, Rohit Kuber, Bhirud, Pankaj, Virmalwar, Ajay
Frontal, Lateral, and Free-Operation Impacts of Amusement Bumper Cars: Vehicle Kinematics and Occupant Kinematics2018-01-05434/3/2018
This study conducted a series of rear-impact, side-impact, barrier, and free-operation collisions using a bumper car ride at an active amusement park. Two conditions were studied: staged and free operation. Each staged test included a bullet (impacting) vehicle operated by a rider and a target (impacted) static vehicle or structure. Impact configurations of frontal collisions of the bullet vehicle into the rear and side of a target vehicle were consistent with the existing literature. The free operation condition involved collisions which were not pre-determined, and operators may not have been prepared for collision timing, magnitude, and direction. Results demonstrated high repeatability for vehicle parameters, such as impact velocity, change in velocity, and peak acceleration. Peak changes in velocity during vehicle-to-vehicle collisions were 2.2-2.5 m/s (8-8.9 km/hr; 5-5.5 mph) for the target vehicle and 1.6-1.8 m/s (5.6-6.4 km/hr; 3.5-4 mph) for the bullet vehicle, while those during vehicle-to-retaining barrier collisions were approximately 3.6 m/s (13 km/hr; 8 mph). Coefficients of restitution and overall vehicle and occupant kinematics were similar to prior bumper car studies, and collision magnitudes were similar in the free-operation test to the staged, single-axis collisions. Bumper cars present a model environment to study vehicle and occupant kinematics in vehicle collisions that are within human tolerance and include aware but possibly unprepared occupants. This is relevant to establishing occupant kinematics in and limits to autonomous vehicle emergency handling maneuvers.
Bussone, William R., Moore, Tara, Locey, Caitlin, Cargill, Robert
Plug-in hybrid brings Honda into sharper Clarity18AUTP02_082/1/2018
Honda's recently introduced Clarity plug-in hybrid sedan is the third variant of this revitalized and electrified nameplate. It joins the Clarity Fuel Cell, which debuted in December 2016 and the Clarity Battery Electric that arrived in the U.S. market in August 2017. The Plug-in Hybrid is the only one that's available in all 50 states and the sole version customers can purchase. The base Plug-in is $33,400 with a more upscale Touring model offering features like leather seats and satellite navigation ringing in at $36,600. Available by lease only, the Fuel Cell is just for California consumption and the Battery Electric version is currently offered only in a couple U.S. West Coast states at present. Honda will also offer the Plug-in in Canada.
Sessions, Ron
Wheel Bearing Brinelling and a Vehicle Curb Impact DOE to Understand Factors Affecting Bearing Loads2017-01-25269/17/2017
As material cleanliness and bearing lubrication have improved, wheel bearings are experiencing less raceway spalling failures from rotating fatigue. Warranty part reviews have shown that two of the larger failure modes for wheel bearings are contaminant ingress and Brinell damage from curb and pothole impacts. Warranty has also shown that larger wheels have higher rates of Brinell warranty. This paper discusses the Brinell failure mode for bearings. It reviews a vehicle test used to evaluate Brinell performance for wheel bearings. The paper also discusses a design of experiments to study the effects of factors such as wheel size, vehicle loading and vehicle position versus the bearing load from a vehicle side impact to the wheel. As the trend in vehicle styling is moving to larger wheels and low profile tires, understanding the impact load can help properly size wheel bearings.
Sutherlin, Robert G.
New HAI-Prevention Cleaning Protocols Reinforce Need for Material Consideration for Medical Device HousingsTBMG-273158/1/2017
As in any industry, new technologies and material choices present new opportunities and challenges for OEMs looking to build brand equity, bring products to market faster, and meet consumer demand. Medical device manufacturers are faced with multifaceted challenges to meet the highest degrees of performance, efficacy, regulatory compliance, and safety in the service of protecting the health and well-being of patients. From the integration of advanced technologies all the way through to the type of material used, every design decision has lasting real-world consequences.
Side Impact Pressure Sensor Predictions with Computational Gas and Fluid Dynamic Methods2017-01-03793/28/2017
Three computational gas and fluid dynamic methods, CV/UP (Control Volume/Uniform Pressure), CPM (Corpuscular Particle Method), and ALE (Arbitrary Lagrangian and Eulerian), were investigated in this research in an attempt to predict the responses of side crash pressure sensors. Acceleration-based crash sensors have been used extensively in the automotive industry to determine the restraint system firing time in the event of a vehicle crash. The prediction of acceleration-based crash pulses by using computer simulations has been very challenging due to the high frequency and noisy responses obtained from the sensors, especially those installed in crush zones. As a result, the sensor algorithm developments for acceleration-based sensors are largely based on prototype testing. With the latest advancement in the crash sensor technology, side crash pressure sensors have emerged recently and are gradually replacing acceleration-based sensor for side crash applications. Unlike the acceleration-based crash sensors, the data recorded by the side crash pressure sensors exhibits lower frequency and less noisy responses. The lower frequency and less noisy response characteristics are more suitable for CAE (Computer Aided Engineering) predictions. Fifteen benchmark tests, in three groups, were designed and conducted to better understand the pressure sensor responses under different impact conditions and to provide data for the evaluation of the three computational gas and fluid dynamic methods. The first group of benchmark tests included a piston compression test with two different gases being compressed in a rectangular container. The second group of benchmark tests consisted of a rigid impactor or a deformable barrier hitting a rectangular steel box with and without a hole as well as at different impact speeds. The third group of benchmark tests involved a rigid impactor or a deformable barrier hitting a vehicle side door with different openings and at different impact speeds. To ensure the robustness of CAE predictions for different test conditions, variables such as, structural design, hole size, hole location, sensor location, impactor type, and impact speed, were considered when designing the fifteen benchmark tests. To choose appropriate approaches for side crash pressure sensor predictions, three computational gas and fluid dynamic methods available for SFI (Structure-Fluid Interaction) applications were evaluated in this research. The three methods, including two computational gas dynamic methods, the CV/UP and CPM methods, and one computational fluid dynamic method, the ALE method, were employed to simulate the fifteen benchmark tests and to understand their corresponding numerical performances. The predictions of the benchmark tests including the structure deformation mode and the pressure response are compared to those of the tests. The advantages and limitations of each method for the different variables are discussed in details based on the results obtained from the numerical simulations. In addition, computation efficiency and user-friendliness for the three methods are also compared. In addition, four full vehicle tests were selected to assure that the pressure sensor prediction capability can be used in the full vehicle test environments. The main objective of this research is to identify the most appropriate methods to predict pressure sensor responses and to enable computer simulations for the development of restraint deployment algorithms associated with the side crash pressure sensors. It is also hoped that the enhancements and developments made throughout this research would allow the three methods to be applied to a broader range of SFI problems.
Tyan, Tau, Shaner, Leonard, Niesluchowski, Matt, Kochhar, Nand, Bhalsod, Dilip, Wang, Jason
Numerical Investigation of the Impact of Nozzle Endwall Clearance Distribution on Variable Nozzle Turbine Performance2017-01-10343/28/2017
As the variable nozzle turbine(VNT) becomes an important element in engine fuel economy and engine performance, improvement of turbine efficiency over wide operation range is the main focus of research efforts for both academia and industry in the past decades. It is well known that in a VNT, the nozzle endwall clearance has a big impact on the turbine efficiency, especially at small nozzle open positions. However, the clearance at hub and shroud wall sides may contribute differently to the turbine efficiency penalty. When the total height of nozzle clearance is fixed, varying distribution of nozzle endwall clearance at the hub and shroud sides may possibly generate different patterns of clearance leakage flow at nozzle exit that has different interaction with and impact on the main flow when it enters the inducer. It is possible that variation of the nozzle endwall clearances between hub side and shroud side, e.g. tiny transverse movement of nozzle vanes along their pivotal shafts, results in significant deviations in turbine aerodynamic performances at some operation conditions. In this paper, the deviations of turbine efficiency at three typical nozzle vane openings and different rotational speeds, with different distribution of nozzle endwall clearances were numerically analyzed. It was found that when the total height of nozzle clearances is fixed, changing the nozzle endwall clearance distribution between the hub and shroud sides can impact the turbine performance, and shifting clearance towards hub side can effectively improve the VNT turbine efficiency, especially at high speed ratio and small vane open positions.
Zhao, Ben, Hu, Liangjun, Engeda, Abraham, Sun, Harold
Speedometers and Collision Reconstruction2017-01-14123/28/2017
Various mechanisms have been used to drive speedometers and other instrument gauges. This paper reviews the mechanisms used; in particular investigates the ability of stepper motors which have become the most common instrument motor in the last decade to freeze at the apparent reading prior to impact. Stepper motors require power to drive the needle to any indicated position, including having to return it to zero. Hence if power to the instrument is lost as a result of a collision, there is no power to move the needle and it should be left at the reading shown at the moment the power was lost. However, not all stepper motor instruments are the same and before accepting the reading, a number of criteria need to be considered to give a level of confidence in the result. As part of recent ITAI (Institute of Traffic Accident Investigators) crash test events in the UK, a number of instrument clusters were installed in vehicles to simulate both frontal and side impacts. Impact speeds were recorded up to 75mph (120Kph). The results show that some instrument types will hold their pre-impact position even during high speed side impacts while others produce erratic readings.
Goddard, Christopher H., Price, David
Accuracy of the Momentum Energy Restitution Method for Offset Inline Minor Rear-End Impacts2017-01-14253/28/2017
In minor inline rear-end accidents, vehicle damage is the primary tangible indicator of impact severity or vehicle change in velocity (ΔV). A technique for calculating change in velocity based on vehicle damage for collinear impacts involves application of the Momentum Energy Restitution (MER) method. Offset inline minor rear-end impact testing, wherein minimal vehicle bumper or contact surface engagement occurs, has not been readily published to date. Thus, instrumented offset inline rear-end impacts were performed utilizing a 1997 Ford F-150 Pickup, 1996 Kia Sephia, and 1995 Chrysler LeBaron GTC to determine if the MER method can accurately calculate a vehicle’s ΔV when collinear contact does not occur. Vehicle engagement involved 5.1 cm to 76.2 cm of overlap with impact speeds ranging between 0.7 m/s and 4 m/s. Test results indicated that a 15.2 cm or less overlap between vehicle impacting surfaces promoted sideswipe impacts or an incomplete transfer of momentum relative to the bullet vehicle’s impact speed. An overlap of greater than 15.2 cm between the vehicle impacting surfaces allowed for complete collisions and transfer of momentum relative to the bullet vehicle’s impact speed. The profile and composition of each vehicle’s impact surface also contributed to complete vs. incomplete collisions. With individual vehicle damage documented before and after each test, application of a modified MER method, which accounts for impacts where measurable crush damage does not occur, was performed based on the measured damage to theoretically calculate each vehicle’s ΔV. The calculated results utilizing the modified MER method were then compared to the test vehicle acceleration traces which were integrated for determination of each test vehicle’s actual ΔV. Comparison of the calculated vs. actual data indicated a high accuracy of prediction (i.e., 1.4 - 33.2% error) for a vehicle ΔV greater than 0.8 m/s via the modified MER method with a vehicle overlap greater than 15.2 cm. When vehicle overlaps were less than 15.2 cm, a sideswipe aspect was introduced and an over calculation (i.e., 202.0 - 844.5 % error) of vehicle ΔV occurred.
Jones, Brian, Calabro, Michael, Brink, Justin, Swinford, Scott
A Comprehensive Validation Method with Surface-Surface Comparison for Vehicle Safety Applications2017-01-02213/28/2017
Computer Aided Engineering (CAE) models have proven themselves to be efficient surrogates of real-world systems in automotive industries and academia. To successfully integrate the CAE models into analysis process, model validation is necessarily required to assess the models’ predictive capabilities regarding their intended usage. In the context of model validation, quantitative comparison which considers specific measurements in real-world systems and corresponding simulations serves as a principal step in the assessment process. For applications such as side impact analysis, surface deformation is frequently regarded as a critical factor to be measured for the validation of CAE models. However, recent approaches for such application are commonly based on graphical comparison, while researches on the quantitative metric for surface-surface comparison are rarely found. To deal with this problem, a validation metric, which combines the discrepancies measurements in magnitude and shape, is proposed to evaluate the inconsistence between two deformed surfaces. For magnitude error, an exploited 2-Dimensional Dynamic Time Warping (2D-DTW) method is applied to address the mismatch in surface features between two surfaces. Geometric features, say mean curvatures of surfaces, are extracted for shape comparison. For decision making, the original assessments are then transformed into scores through a linear regression method. An analytical case is employed to verify the employed algorithms in the proposed method. Furthermore, the method is implemented on a real-world case involving surface comparison to show its potential in vehicle safety applications.
Wang, Changsheng, Yang, Junqi, Zhan, Zhenfei, Zheng, Ling, Guo, Gang
Crush Energy and Stiffness in Side Impacts2017-01-14153/28/2017
Crash tests of vehicles by striking deformable barriers are specified by Government programs such as FMVSS 214, FMVSS 301 and the Side Impact New Car Assessment Program (SINCAP). Such tests result in both crash partners absorbing crush energy and moving after separation. Compared with studying fixed rigid barrier crash tests, the analysis of the energy-absorbing behavior of the vehicle side (or rear) structure is much more involved. Described in this paper is a methodology by which analysts can use such crash tests to determine the side structure stiffness characteristics for the specific struck vehicle. Such vehicle-specific information allows the calculation of the crush energy for the particular side-struck vehicle during an actual collision – a key step in the reconstruction of that crash. Based on fundamental principles of physics and engineering, this methodology provides transparency in the calculation of side structure stiffness parameters for the particular vehicle of interest. Additionally, sample calculations are presented. Utilizing widely available computational tools and publicly available test data, the method was applied to a representative sample of recent-model vehicles. The results of this study show that variability in side structure stiffness from vehicle to vehicle appears to be real – not an artifact of computational method or data uncertainty – and not necessarily related to vehicle size or weight, for example. Independent tests of comparable vehicles, while few in number, produce remarkably similar stiffness results. Supported by sensitivity analyses, various simplifications are presented that in most cases will allow a good approximation to more rigorously-derived results.
Struble, John D., Struble, Donald E.
Application of Lateral Pole Impact Force-Displacement Data to the Reconstruction of Side Impacts with Narrow Objects2017-01-14163/28/2017
Reconstruction of passenger vehicle accidents involving side impacts with narrow objects has traditionally been approached using side stiffness coefficients derived from moveable deformable barrier tests or regression analysis using the maximum crush in available lateral pole impact testing while accounting for vehicle test weight. Current Lateral Impact New Car Assessment Program (LINCAP) testing includes 20 mph oblique lateral pole impacts. This test program often incorporates an instrumented pole so the force between the vehicle and pole at several elevations along the vehicle - pole interface is measured. Force-Displacement (F-D) characteristics of vehicle structures were determined using the measured impact force and calculated vehicle displacement from on-board vehicle instrumentation. The absorbed vehicle energy was calculated from the F-D curves and related to the closing speed between the vehicle and the pole by the vehicle weight. The presented approach resulted in approximately a 2% underestimation of closing speed in large four-door sedans and approximately a 9 to 10% underestimation in large four-door pickup trucks. Accounting for structural restoration is important when assessing accident severity using this methodology. The nominal restoration of the vehicle structures was generally calculated to be in the 17 to 21% range. Furthermore, comparison of F-D curves between vehicle classes and different elevations on a given vehicle is useful for assessment of field crashes, which can occur in various orientations.
Ault, B. Nicholas, Toomey, Daniel E.
Ambulance Litter Integrity, Retention, and Patient RestraintJ3027_201611 (Historical)11/1/2016
This SAE Recommended Practice describes the testing procedures required to evaluate the integrity of a ground ambulance-based patient litter, litter retention system, and patient restraint when exposed to a frontal, side or rear impact. Its purpose is to provide litter manufacturers, ambulance builders, and end-users with testing procedures and, where appropriate, acceptance criteria that, to a great extent ensures the patient litter, litter retention system, and patient restraint utilizes a similar dynamic performance test methodology to that which is applied to other vehicle seating and occupant restraint systems. Descriptions of the test set-up, test instrumentation, photographic/video coverage, test fixture, and performance metrics are included.
Truck Crashworthiness Committee
Full Instrumentation of Side Impact Pole and In-Depth Analysis of Vehicle Structural Behavior2016-36-012810/25/2016
In order to obtain more information from the side impact tests, a pole was fully instrumented with triaxle load cells. Also, a sled modification was carried out providing a sub-frame view of the vehicle during the entire test and making possible to compare the structure and element deformations with the obtained data. An in-depth analysis of vehicle structural behavior focused on the forces received by the vehicle during the pole side impact test was made. A crash test was set to validate the acquisition system of the instrumented pole. The obtained data like the forces and the deformations were analyzed in depth and used for a structural study of the vehicle. The data acquired by the acquisition system was used to obtain a force diagram from the pole and a comparison was made with the vehicle absorption mechanisms and structural elements involved. Moreover, the force data was compared with the sub-frame view and with the structural element’s deformation. With the results, it was possible to have a complete view of the interaction between the vehicle and the pole and how it affects the vehicle structure during the entire test. In order to obtain those results, frame to frame with the high-velocity videos form different positions were obtained and the sub-frame view of the car during the test was used This kind of study are carried out for the clients, due to confidentiality reasons no pictures will be sown in this paper. The fully instrumentation of the pole and the sub-frame vision will make it possible to know the most critical parts of the vehicle structure in the side impact pole test and their performance. Also, it will help to define the structural parts that need to be improved in the vehicle and the different aspects that need to be taken into account in order to guarantee the safety of the occupants.
Sanchez, Jacob, Malivern, Melcior, Parera, Núria, Fornells, Alba
Advanced Heavy Truck Frame Design and Opportunities for Fuel System Impact Protection2016-01-80499/27/2016
Frame rail design advances for the heavy truck industry provide numerous opportunities for enhanced protection of fuel storage systems. One aspect of the advanced frame technology now available is the ability to vary the frame rail separation along the length of the truck, as well as the depth of the frame. In this study, the effect of incorporating the fuel storage system within advanced technology tapered frame rails was evaluated using virtual testing under impact conditions. The impact performance was evaluated under a range of horizontal impacts conditions. The performance observed was quantified and then compared with previous testing of baseline diesel tank systems. Fuel storage system impact performance metrics over the range of crash conditions considered were quantified using virtual testing methods. The results obtained from the application of the impact performance evaluation methodology were then described. The results indicated that substantial improvements in fuel storage system impact protection were available utilizing the advanced tapered frame rail technology. Opportunities available with the use of advanced frame technologies were described.
Friedman, Keith, Bui, Khanh, Hutchinson, John, Stephens, Matthew, Gonzalez, Francisco
Occupant Restraint and Equipment Mounting Integrity – Side Impact Ambulance Patient CompartmentJ2956_201608 (Historical)8/23/2016
This SAE Recommended Practice describes the test procedures for conducting side impact occupant restraint and equipment mounting integrity tests for ambulance patient compartment applications. Its purpose is to describe crash pulse characteristics and establish recommended test procedures that will standardize restraint system and equipment mounting testing for ambulances. Descriptions of the test set-up, test instrumentation, photographic/video coverage, and the test fixtures are included.
Truck Crashworthiness Committee
Impact of Light-Weight Design on Manufacturing Cost - A Review of BMW i3 and Toyota Corolla Body Components2016-01-13394/5/2016
OEMs are investigating opportunities to reduce vehicle mass, driven by a need to meet upcoming CAFE targets, increase the range and reduce battery size of EVs. A number of lightweight materials including high strength steels, aluminum alloys, plastics and composites are now in production. To facilitate development of corporate R&D and commercialization plans for new materials, it is beneficial to understand the current manufacturing costs for production components, and their impact on piece price at different volumes. This paper investigates design and cost impact of light-weighting with respect to front door and floor assembly of Toyota Corolla and BMW i3. Toyota Corolla has a traditional steel body and is sold in high volumes while BMW i3 has relatively low annual sales and is primarily made of composite, aluminum and plastic parts. This study identifies good practices by BMW for both light-weighting and low / medium volume production where reduction in tooling costs become significant. Differences in design, manufacturing processes, production costs as well as cost of light-weighting ($/lb saved) between the Corolla and i3 subassemblies are discussed. The analysis was performed under ARPA-E funding and is based on review of component teardown data, identification of manufacturing and assembly processes. Ricardo developed a database and detailed analysis model to calculate cost to manufacture at various production volumes.
Bubna, Piyush, Wiseman, Marc
Body-in-White Reinforcements for Light-Weight Automobiles2016-01-03994/5/2016
Automotive OEMs are proactively working on vehicle light-weighting, powertrain optimization, alternate/renewable energy sources and combinations of the three to meet challenging corporate average fuel economy (CAFE) standards. Light-weighting of the body-in-white (BIW) is an obvious choice for vehicle light-weighting as this structure contributes to more than 30-35% of the total weight of a car. Changing manufacturing and assembly lines requires substantial investment. As such, OEMs are exploring short-term light-weighting strategies that do not require any major changes to the BIW. Local reinforcement for the BIW are pertinent solutions that does not require any major changes in the existing assembly lines. This paper focuses on the development of BIW reinforcement solutions using engineering thermoplastic materials that can be mounted at appropriate locations on a vehicle’s BIW to achieve significant weight savings without compromising crash performance. Various design and material configurations - including plastic, metal-plastic and composite-plastic structural members - mounted on the BIW are evaluated through CAE studies for various crash scenarios such as high-speed frontal crashes, side impact, pole impact and rollover. The CAE studies, performed using generic vehicle models, quantify the potential weight-savings in a vehicle by either replacing the existing reinforcements using a lighter system or by incorporating additional reinforcements in the BIW by down-gauging the existing BIW. Approaches to correlate the CAE studies using component level testing and validation of generic reinforcements are also investigated. Data from all of this work indicate that the use of BIW reinforcements can achieve significant weight reduction (∼ 1.5%) in a vehicle, while also ensuring no compromise in crash performance.
Munjurulimana, Dinesh, Kulkarni, Amit, Nagwanshi, Dhanendra, Thambi, Joel Luther, Winters, Ruud, Delaney, Matthew
Alternative Approaches to Occupant Response Evaluation in Frontal Impact Crash Testing2016-01-15404/5/2016
The National Highway Traffic Safety Administration has performed research investigating the Test Device for Human Occupant Restraint 50th male (THOR-50M) response in Oblique crash tests. This research is being expanded to investigate THOR-50M in the driver position in a 56 km/h frontal impact crash. Hybrid III 5th percentile adult female (AF05) anthropomorphic test devices (ATDs) were used in this testing to evaluate the RibEye Deflection Measurement System. The AF05 ATDs were positioned in the right front passenger and right rear passenger seating positions. For the right front passenger, the New Car Assessment Procedure (NCAP) seating procedure was used, except the seat fore-aft position was set to mid-track. For the right rear passenger, the seating followed the FMVSS No. 214 Side Impact Compliance Test Procedure. The NCAP frontal impact test procedure was followed with additional vehicle instrumentation and pre/post-test measurements. Results from this test series were compared with previous NCAP crash tests. The THOR-50M showed similar kinematics to the Hybrid III 50th but predicted a higher risk of chest and femur injury. The mid-track seat position of the right front passenger AF05 led to lower levels of femur compression loading due to additional distance to the dash. BrIC for the driver and front passenger showed higher injury risk than HIC15. In all vehicles, the rear seat AF05 predicted a substantially higher risk of head, neck and chest injury than the right front passenger. The AF05 RibEye output showed a higher peak deflection (x-axis) than the chest potentiometer.
Keon, Timothy
A Research on the Prediction of Door Opening by the Inertia Effect during a Side Impact Crash2016-01-15324/5/2016
The purpose of this study is to develop a dynamic model that can accurately predict the motion of the door handle and counterweight during side impact crash tests. The door locking system, mainly composed of the door outside handle and door latch, is theoretically modeled, and it is assumed that the door outer panel can rotate and translate in all three directions during a side impact crash. Additionally, the numerical results are compared with real crash video footage, and satisfactory qualitative agreement is found. Finally, the simplified test rig that efficiently reflects the real crash test is introduced, and its operation is analyzed.
Kwak, Kyoungtaek, Seo, Seungwoo, Potekin, Randi, Blanchard, Antoine, Vakakis, Alexander, McFarland, Donald, Bergman, Lawrence
Crashworthiness Design of Automotive Body in White using Topology Optimization2016-01-15354/5/2016
Based on equivalent static loads method (ESL), a nonlinear dynamic topology optimization is carried out to optimize an automotive body in white (BIW) subjected to representative legislative crash loads, including frontal impact, side barrier impact, roof crush and rear impact. To meet the crashworthiness performances, two evaluation indexes are defined to convert the practical engineering problems into mathematic optimization problems. The strain energy is treated as the stiffness evaluation index of the BIW and the relative displacement is employed as the compliance index of the components and parts. The optimization problem could be changed into maximizing structural stiffness of the design space while constraining the relative displacements of the passenger cabin lower than a certain value to guarantee the stiffness of passenger cabin, constraining the relative displacements of the front and rear cabin greater than a certain value to increase the energy absorption during the crash process. The results provide a conceptual design which emphasizes the most efficient load paths and could be served as an effective guidance to the next-step BIW detailed design.
Tian, Linli, Gao, Yunkai
Multidisciplinary Optimization under Uncertainty Using Bayesian Network2016-01-03044/5/2016
This paper proposes a novel probabilistic approach for multidisciplinary design optimization (MDO) under uncertainty, especially for systems with feedback coupled analyses with multiple coupling variables. The proposed approach consists of four components: multidisciplinary analysis, Bayesian network, copula-based sampling, and design optimization. The Bayesian network represents the joint distribution of multiple variables through marginal distributions and conditional probabilities, and updates the distributions based on new data. In this methodology, the Bayesian network is pursued in two directions: (1) probabilistic surrogate modeling to estimate the output uncertainty given values of the design variables, and (2) probabilistic multidisciplinary analysis (MDA) to infer the distributions of the coupling and output variables that satisfy interdisciplinary compatibility conditions. A copula-based sampling technique is employed for efficient sampling from the joint and conditional distributions. The proposed MDO methodology is implemented within a framework of reliability-based design optimization. The proposed Bayesian network surrogate model and copula sampling are used for efficient reliability assessment within the optimization framework. A mathematical example and an aeroelastic aircraft wing design are used to demonstrate the proposed probabilistic MDO methodology
Liang, Chen, Mahadevan, Sankaran
Surface Generation speeds composites throughput with one-shot stamp-forming process16AUTP02_072/1/2016
Surface Generation is working with research group WMG, an academic department of the University of Warwick, and AGC AeroComposites to develop new composite press-forming processes for automotive and aerospace manufacturers. Surface Generation, a U.K.-based provider of advanced carbon-fiber processing technologies, is developing new press-forming mold faces that incorporate its patented PtFS (Production to Functional Specifications) technology for the production of high-performance thermoplastic composite components. By integrating Surface Generation's active thermal management technologies into the mold face itself, WMG and AGC are able to continuously adapt heating and cooling levels for each mold area and process stage in real time. The companies believe that this enhanced capability will improve both the quality and throughput of compression molding applications.
Gehm, Ryan
Surface Generation speeds composites throughput with one-shot stamp-forming process16OFHP02_062/1/2016
Surface Generation is working with research group WMG, an academic department of the University of Warwick, and AGC AeroComposites to develop new composite press-forming processes for automotive and aerospace manufacturers. Surface Generation, a U.K.-based provider of advanced carbon-fiber processing technologies, is developing new press-forming mold faces that incorporate its patented PtFS (Production to Functional Specifications) technology for the production of high-performance thermoplastic composite components. By integrating Surface Generation's active thermal management technologies into the mold face itself, WMG and AGC are able to continuously adapt heating and cooling levels for each mold area and process stage in real time. The companies believe that this enhanced capability will improve both the quality and throughput of compression molding applications.
Gehm, Ryan
Responses of the Q6/Q6s ATD Positioned in Booster Seats in the Far-Side Seat Location of Side Impact Passenger Car and Sled Tests2015-22-001211/9/2015
Passenger car side impact crash tests and sled tests were conducted to investigate the influence of booster seats, near-side occupant characteristics and vehicle interiors on the responses of the Q6/Q6s child ATD positioned in the rear, far-side seating location. Data from nine side impact sled tests simulating a EuroNCAP AEMD barrier test were analyzed with data obtained from 44 side impact crash tests. The crash tests included: FMVSS 214 and IIHS MDB, moving car-to-stationary car and moving car-to-moving car. A Q6 or prototype Q6s ATD was seated on the far-side, using a variety of low and high back booster seats. Head and chest responses were recorded and ATD motions were tracked with high-speed videos. The vehicle lateral accelerations resulting from MDB tests were characterized by a much earlier and more rapid rise to peak than in tests where the bullet was another car. The near-side seating position was occupied by a Hybrid III 10-year-old ATD in the sled tests, and a rear or front facing child restraint or a 5th percentile side impact ATD in the crash tests. Head impacts occurred more frequently in vehicles where a forward facing child restraint was present behind the driver seat for both the low and high back booster seats. Pretensioners were found to reduce lateral head displacements in all sled test configurations but the greatest reduction in lateral excursion was obtained with a high back booster seat secured with LATCH and tested in combination with pretensioners.
Tylko, Suzanne, Bohman, Katarina, Bussières, Alain
A Study on New Approach of Optimization for the Automotive Plastic Interior Parts2015-01-04764/14/2015
Carmakers have tried to lower the vehicle weight for raising fuel efficiency. This trend involves a trade-off with the vehicle stiffness. In automobile interior parts, the thickness has needed to be decreased for the weight reduction but this makes the stiffness worse. A new approach for improving the stiffness due to the weight reduction is required and various optimization methods at early development stage have been introduced currently. However, it is difficult to apply optimization for the interior parts since many interior parts' structures generally depend on the design. But as studying the structure in detail, we discovered some factors that affect the performance without depending on design. The door trim is selected for optimization item because it has many characteristics of automobile interior parts. In our case study, the factors that improve the performance of door trim without changing design are considered as fastener position and flange rib layout. The optimization process for door trim was established. Size optimization is used for Fastener position and Topology optimization is used for Flange rib layout. As a result, the 1st mode frequency is improved by about 5% and thermal displacement is reduced by about 25% in comparison with the initial model.
Jo, Hyunkwon, Kim, Youngseung, Lee, Hyunchul, Park, Hyunmin, Song, Suckin
Injury Sources for Second Row Occupants in Frontal Crashes Considering Age and Restraint Condition Influence2015-01-14514/14/2015
The current study examined field data in order to document injury rates, injured body regions, and injury sources for persons seated in the second row of passenger vehicles. It was also intended to identify whether these varied with respect to age and restraint use in vehicles manufactured in recent years. Data from the 2007-2012 National Automotive Sampling System (NASS/CDS) was used to describe occupants seated in the second row of vehicles in frontal crashes. Injury plots, comparison of means and logistic regression analysis were used to seek factors associated with increased risk of injury. Restraint use reduced the risk of AIS ≥ 2 injury from approximately 1.8% to 5.8% overall. Seventy nine percent of the occupants in the weighted data set used either a lap and shoulder belt or child restraint system. The most frequently indicated injury source for persons with a MAIS ≥ 2 was “seat, back support”, across restraint conditions and for all but the youngest occupants. The factors most strongly associated with injury risk in the crash dataset were the velocity difference (delta V) and age, which had significant association with injury risk in restrained occupants of the second row. These data suggest that prevention of injurious contact with the back of the front seat may be an important factor in efforts to reduce the injury rate in second row passengers regardless of age and restraint condition.
Gudlur, Anand Sai, Atkinson, Theresa
Development of a Small Rear Facing Child Restraint System Virtual Surrogate to Evaluate CRS-to-Vehicle Interaction and Fitment2015-01-14574/14/2015
Automotive interior design optimization must balance the design of the vehicle seat and occupant space for safety, comfort and aesthetics with the accommodation of add-on restraint products such as child restraint systems (CRS). It is important to understand the range of CRS dimensions so that this balance can be successfully negotiated. CRS design is constantly changing. In particular, the introduction of side impact protection for CRS as well as emphasis on ease of CRS installation has likely changed key design points of many child restraints. This ever-changing target creates a challenge for vehicle manufacturers to assure their vehicle seats and occupant spaces are compatible with the range of CRS on the market. To date, there is no accepted method for quantifying the geometry of child seats such that new designs can be catalogued in a simple, straightforward way. In this project, we propose to quantify the geometry of a selection of CRSs currently on the market and develop an easily implementable method to continue to collect this data as new CRSs become available. Computer Aided Design (CAD) data was collected for 40 CRS models (Rear-facing infant seats, convertible, and combination CRS). These 40 models represent 72 CRS models on the US market as of April 2013. Twenty-two CRS were scanned and digitized using a novel approach with the Microsoft Kinect Sensor. The scans were converted into surface models and finite element (FE) models using Hypermesh 12.0 (Altair Inc., MI). CRS manufacturers provided digital drawings of 18 additional CRS. The scans and digital drawings were overlapped at typical seat angles from literature data to create virtual surrogates. The use of virtual surrogates by vehicle manufacturers in the design and development of the rear-seat vehicle environment early on in the design-development cycle has the potential to facilitate improved CRS-vehicle fitment.
Belwadi, Aditya, Hanna, Richard, Eagle, Audrey, Martinez, Daniel, Kleinert, Julie, Dahle, Eric
The Development of a Non-Linear Pressure Model of the FMVSS 214D Moving Deformable Barrier for Use in HVE2015-01-14304/14/2015
The analysis and modeling of vehicle crush in accident reconstruction has traditionally been based upon the use of linear, crush-based, stiffness coefficients. Recent advances have allowed for the calculation and implementation of non-linear crush coefficients in the accident reconstruction software Human-Vehicle-Environment (HVE) by Engineering Dynamics Corporation (EDC). HVE contains the collision algorithm called DyMESH (DYnamic MEchanical SHell), which is capable of using the non-linear coefficients. These non-linear coefficients have shown to increase the accuracy of a predicted crash pulse. Published research on non-linear crush coefficients for the use in HVE has been limited to frontal impacts. Calculating side stiffness coefficients is more complex since most side impact crash tests involve two vehicles that can crush and absorb impact energy. One type of side impact test is described in Federal Motor Vehicle Safety Standard (FMVSS) 214D, which involves a crabbed Moving Deformable Barrier (MDB) impacting a stationary subject vehicle. To calculate the crush coefficients of the subject vehicle, the crush characteristics of the MDB must first be established. Once the MDB coefficients are calculated, the side stiffness of the subject vehicle can be calculated. The aim of this research was to develop an MDB model for use in HVE and to calculate the non-linear crush coefficients for the MDB. The model, and established crush coefficients, were used in HVE to simulate MDB-to-rigid barrier tests. The simulation results regarding crash pulse duration and peak values, vehicle kinematics, and predicted crush to the MDB were compared to the actual crash test to assess the quality of the non-linear coefficients of the MDB.
Gilbert, Brian, McCarthy, Joseph, Jadischke, Ron
Research on Three Main Lightweight Approaches for Automotive Body Engineering Considering Materials, Structural Performances and Costs2015-01-05804/14/2015
Lightweight automotive body can be obtained by developing new body constructions, using lightweight materials and structural optimizations, etc. Usually, lighter materials and structural optimizations are main aspects considered in lightweight automotive body engineering. In fact, material costs and manufacturability play more important roles than others in lightweight design. Three lightweight design approaches are considered. The first approach of lightweight design is to replace steels with lighter materials using equal rigidity design method. The second approach is a single objective optimization of mass reduction with materials selection and cost penalty. The third approach is a multi-objective optimization of mass reduction and cost reduction using multi-material concept. These three approaches are applied to an automotive body design problem considering the side impact. Different optimization methods are used to obtain different results. Design aspects, such as sizes of components, types of materials and costs can be optimized. Type of lightweight optimization is then a choice of manufacturer's concern.
Lei, Fei, Chen, Xin, Xie, Xiao Ping, Zhu, Jing
Development and Implementation of a Quasi-Static Test for Seat Integrated Seat Belt Restraint System Anchorages2015-01-07394/14/2015
Over the last decade large safety improvements have been made in crash protection for motorsports drivers. It has been well established that in side and rear impacts the driver seat provides the primary source for occupant retention and restraint. Beginning in the 2015 season, NASCAR®'s (National Association for Stock Car Auto Racing, Inc) Sprint Cup Series will require driver seats which have all seat belt restraint system anchorage locations integrated internally to the seat with a minimum of seven anchorage locations. This paper describes the development of the quasi-static test for the seat integrated seat belt restraint system portion of the NASCAR Seat Submission and Test Protocol Criteria. It reviews the methodology used to develop the testing including the developmental dynamic sled tests.
Patalak, John, Gideon, Thomas
Structure Optimization For Installation Position of Side Impact Sensor Using Frequency Response Analysis2015-01-06184/14/2015
Based on the modal frequency response theory and experiment, the installation layout evaluation and structural optimization method for SIS(side impact sensors) installation position is studied. Establish the finite element model including B-pillar, roof and floor with local constraint. Than study the key parameter's influence on the frequency response analysis results, and the simulation results are correlated by experiment. In view of the installation layout requirements of side impact sensors, the structure optimization method for installation position of side impact sensor is put forward. The optimal scheme is confirmed by the finite element analysis, and a final experimental verification was implemented by a real vehicle test.
Dong, Zhihong, Sun, Ying, Zhu, Guitao, Wang, Shihu, Zeng, Jian, Yang, Yuliang
Assessment of Similarity of a Set of Impact Response Time Histories2015-01-14414/14/2015
Two methods of assessing the similarity of a set of impact test signals have been proposed and used in the literature, which are cumulative variance-based and cross correlation-based. In this study, a normalized formulation unites these two approaches by establishing a relationship between the normalized cumulative variance metric (v), an overall similarity metric, and the normalized magnitude similarity metric (m) and shape similarity metric (s): v=1 − m · s. Each of these ranges between 0 and 1 (for the practical case of signals acquired with the same polarity), and they are independent of the physical unit of measurement. Under generally satisfied conditions, the magnitude similarity m is independent of the relative time shifts among the signals in the set; while the shape similarity s is a function of these. An optimal alignment is defined as the relative shifts corresponding to the minimum of the cumulative variance metric, or equivalently, to the maximum of the shape similarity metric. This system therefore quantifies the similarity of a given set of signals with an “as given” relative time alignment with the following: v = 1− m(p + sa), i.e., its overall similarity is partitioned into the shift-invariant normalized magnitude metric m, and the inherent (optimally aligned) normalized shape metric sa, and a normalized phase metric p which reflects the alignment. An algorithm is provided for automatic search of the optimal shifts for a given set of signals using the cumulative variance as the objective function. The shifts are treated as real numbers instead of integers so that standard continuous variable optimization functions can be used to treat the discrete signals. This is facilitated by an interpolation procedure for shifting a signal with a real-valued time shift. Numerical examples are presented to demonstrate the general effectiveness of the algorithm, and also specific limitations on consistent convergence to the global optimal. Practical measures that would mitigate the limitations and alternative numerical methods that would fundamentally remove these are suggested.
Shi, Yibing, Nusholtz, Guy
A Data Mining-Based Strategy for Direct Multidisciplinary Optimization2015-01-04794/14/2015
One of the major challenges in multiobjective, multidisciplinary design optimization (MDO) is the long computational time required in evaluating the new designs' performances. To shorten the cycle time of product design, a data mining-based strategy is developed to improve the efficiency of heuristic optimization algorithms. Based on the historical information of the optimization process, clustering and classification techniques are employed to identify and eliminate the low quality and repetitive designs before operating the time-consuming design evaluations. The proposed method improves design performances within the same computation budget. Two case studies, one mathematical benchmark problem and one vehicle side impact design problem, are conducted as demonstration.
Xu, Hongyi, Chuang, Ching-Hung, Yang, Ren-Jye
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