Browse Topic: Frontal collisions

Items (407)

Effectiveness of the Load Legs in Enhancing the Passive Safety of Rear-Facing Child Seats in Frontal Crash

2024-26-034301/16/2024

The passive safety performance of a child seat is modulated by the design features of the child seat and the vehicle interior. For example, in the rear-facing configuration, the child seat impacting front structures increases the head injury risk during a frontal crash. Therefore, this study evaluates the effectiveness of the load leg countermeasure in improving the child seat's overall kinematics and its capability to prevent the secondary impact on the vehicle interior structure in a severe frontal crash scenario. An in-depth, real-world crash investigation involving a properly installed rear-facing child seat impacting the center console is selected for the study where the infant sustained a severe brain injury. In addition, this crash is employed to choose the crash parameters for evaluating the effectiveness of the load leg countermeasure in a similar scenario. Finally, crash sled tests are conducted using the crash signature of the vehicle as obtained from the NHTSA NCAP rigid

Thorbole, Chandrashekhar

PERFORMANCE OF FIVE-POINT SEAT BELT ON OCCUPANT SAFETY IN VEHICLE ON FRONTAL CRASH TEST

2022-28-049311/18/2022

In day-to-day life, accidents do occur frequently all-round the globe. It is difficult to prevent these accidents as they occur due to different reasons, which cannot be easily controlled. But the fatal injuries occurring to passengers can be reduced by installing safety systems in vehicles, which will help in saving the life of mankind. There are many safety systems being installed in vehicles such as seat belt restraints, air bags etc. Generally, three-point seat belts are installed in passenger vehicles for safety purposes. This type of seat belt doesn't arrest the entire motion of the occupant body during vehicle crashes, which can lead to fatal injuries and sometimes even death during vehicle crashes. In order to buckle passengers with seats, we can use five-point seat belts which will help in mitigating the injuries as compared to three-point seat belts. In this paper, we evaluate the performance of five-point seat belts on occupant safety during vehicle crash on flat rigid

Jeyakumar, P, CHANDRAN, DINESHKUMAR

Assessment of fetus injury risk during vehicle frontal impact for different lap belt positions

2022-01-102203/29/2022

The paper addresses vehicle safety for pregnant drivers and passengers. The influence of the different positions of the lap part of the seat belt for pregnant female drivers and passengers on the injury risk is assessed. The finite element based pregnant abdomen model is incorporated into the simplified validated rigid body based female body model. The pregnant female model is positioned into a frontal seat and restrained by a safety system such as three-point seat belt and an airbag to simulate the sled test scenario. The deceleration pulse corresponding to a frontal impact related to two impact velocities is applied and the restraint system performance is assessed with focus on the fetus and female injury risk. The uterus is modelled via so called biobag and mechanical loading and injury risk of this particular part and adjacent structures are the main concern of this study.

Spicka, Jan, Hyncik, Ludek, Jansova, Magdalena, Talimian, Abbas

Using Artificial Intelligence to Determine the Speed Change of Frontal Collisions

2022-01-099803/29/2022

The speed change (Delta-V) sustained by a vehicle during a collision is a key element in many traffic collision investigations. Accident reconstructionists have a variety of investigation techniques that can be used to estimate speed change including crush energy, momentum based simulations and event data recorders. This paper proposes that artificial intelligence can be used to analyze photos of damaged vehicles in order to estimate the speed change. An artificial intelligence model was trained using images from over 1000 investigations of frontal collisions (the training set). The resulting model was tested using images from a new set of 250 frontal collision investigations (the test set). In about 85% of the test set, the resulting model predicted the speed change to within ±5mph of the original collision investigation results. By adopting artificial intelligence based algorithms, the accident reconstruction community can gain an additional check on their speed change calculations

Second-Row Children Fatalities in Front and Rear Crashes

2022-01-103603/29/2022

Objective: The protection of children in the second row in automotive crashes remains an important area of safety research. Field data is analyzed on second-row children in front and rear crashes to study fatality trends in 1980-2020 model-year vehicles and to investigate the safety improvements with higher head restraints, stronger front seats and increased use of restraint systems. Methods: 1990 to 2019 FARS was queried to assess the number of fatally injured second-row children (0-15 years old). The children included outboard occupants seated behind an occupied front seat and center occupants. The data was analyzed for rear and frontal crashes by calendar and model year. Results: The number of child fatalities decreased by calendar years and model years. There were 2.95-times more fatally injured children in frontal crashes than in the rear crashes. The relative risk decreased with MY (model year) of the vehicle. For example, it was 3.6-times higher in 1990-1999 MY vehicles and 2.3

Parenteau, Chantal, Viano, David, Lau, edmund

Investigations of Honeycomb and Foam structures of Automotive Front rails During Frontal crashes and its affinity with Optimum Energy Absorption

2022-01-104903/29/2022

Energy dissipation in frontal crash of the vehicles normally occurs through the deformation in the engine compartment zone and especially on longitudinal front rails. In this article, the details of the crash tests is presented which involves an interpretation of the damage profiles and understanding the origin of the stiffness coefficients in main particular member which is front rails of a passenger vehicle. Moreover, the present experimental work is used to estimate the energy dissipated during deformation based on crush measurements. Furthermore, it explains the implementation of experimental test to investigate the influence of design characteristics on the deformation behavior of the proposed front rails. The current experimental work deals with the influences of geometric shape modifications of conventional steel members with flange configurations compared to honeycomb structures and structural foam with the same members length. The observations in this work led to conclude the

Elhussieny, Sayed Abbas, Oraby, Walid

A Study on the Robust Crash Performance Structure of Continuous Fiber Thermoplastic Composite Cowl Crossbar

2022-01-105603/29/2022

Since the 1990s, an increasing amount of research has been done in the automotive industry, not only to improve vehicle production efficiency and performance but also for environmental preservation and enhanced recycling. For this reason, recently, keen interest has been focused on the reduction of fuel consumption through the development of eco-friendly and weight-effective vehicles. This is due in part to the strengthening of regulatory standards for fuel efficiency in each country. This study will focus on the high crash safety performance and the optimization of the IP module, in particular, the cowl crossbar, which in most vehicles, can account for more than 33% of the total weight. In fact, the cowl crossbar is the main part of the vehicle that must support the duct system, steering column module as well as the entire IP module. Therefore, it requires a high stiffness to meet the performance requirements for NVH, durability, and crash protection. For example, during a frontal

Kim, Heeseok, KIM, IL SANG, JAE HYUN, AN, IN SOO, HAN, CHOI, IKKEUN, Park, Sanghyeon

Design and Optimization of an Electric Car Chassis and Body using Structural Analysis and CFD

2022-01-033903/29/2022

The transition from traditional gasoline-powered automobiles to electric vehicles (EVs) has taken time, two major challenges of engine- powered vehicles are greenhouse gas emissions and fuel economy. Electric cars require less maintenance. A lot of money can be saved while also helping the environment. In today's world, working with lightweight materials have emerged as a key area for improvement in the automotive industry. The most efficient method for increasing power output is to reduce the weight of vehicle components. Composite materials have benefited greatly from research and development because they are stronger, more recyclable, and easier to integrate into vehicles. The primary goal of this research is to design the body and chassis frame of a two-seater electric car. A CFD analysis was performed to determine the drag coefficient of the body along with structural analysis to obtain the frontal impact and torsional rigidity of the chassis to develop an effective electric car

Aiyan, Mohammed, Raghav S, Sanjay, Sagar, S Sumanth

The Role of Three-Point Restraints for Occupants in Moderate and Higher Severity Frontal Impact Collisions

2022-01-102603/29/2022

Field accident data and vehicle crash testing have shown that kinematics, occupant loading, , and associated injury risk generally increase with crash severity. Further, these data demonstrate that the use of restraints, such as three-point belts, provides mitigation of kinematics and reduction in loading and injury rates. This study evaluated the role of seat belts in controlling occupant kinematics and reducing occupant loading in moderate and higher severity frontal collisions. Frontal tests with belted and unbelted anthropomorphic test devices (ATDs) in the driver and right front passenger seats were performed at delta-Vs of approximately 19 kph and 32 kph with no airbag deployment. At the lower severity, the belted ATDs’ motion was primarily arrested by seat belt engagement, mitigating contact with forward vehicle structures, while the unbelted ATDs’ motion was largely arrested by interaction with forward vehicle structures. Injury metrics were generally lower with belt use than

Isaacs, Jessica L., George, Juff, Campolettano, Eamon, Cutcliffe, Hattie, Miller, Bruce

Reconstruction of an auto-rickshaw frontal crash using FE simulation with validation using captured crash video from India

2021-28-025710/01/2021

The three wheeled “Auto-Rickshaws” [Auto] plays a significant role in road transportation, especially in India. The crash safety and reconstruction studies have been widely used in four wheelers, whereas the availability of such data for Auto was found to be limited. In recent times, accident data processing from available videos is being utilised to observe the crash scenario, from which the crash parameters can be given as inputs to the crash analysis. This paper focusses on process the real-world accident data and study crash characteristics. With limitation in availability of detailed injuries post-crash, the study was restricted to reconstruction of crash kinematics and estimations of indicative injuries to driver. The source of video data is videos of crash available in public domains like YouTube. PYTHON video processing tool has been used to process the set of real-world accident video data. The object detection, Pixel per meter computation and object tracking are the major

S, Ragul, Sankarasubramanian, Hariharan, Kondaveeti, N S V Nikas, Yadav, Pandugayala Nithin

Engineering challenges in Alloy wheel rim for safety simulations

2021-26-036209/22/2021

Aluminium alloy wheels are widely used in the automotive industry over the last decade due to its superior styling and performance. Alloy wheel rim is one of the critical components and plays an important role in a frontal crash scenario. Alloy wheel rim failure prediction in safety simulation is essential to ensure robust safety performance. Determining failure characteristics of an alloy wheel poses many difficulties considering its brittle nature, porosity and inhomogeneity in material properties across different regions of wheel rim due to mould design, cooling rate and other process parameters of the low-pressure die casting process. This paper describes the modelling and simulation methodology developed to predict accurate wheel behaviour. The methodology addresses two distinct areas of challenges such as alloy wheel rim failure prediction and associated tire blow out. Alloy wheel rim material was characterised considering the inhomogeneity of material properties at different

Koralla, Sivaprasad, Tiwari, Sourabh, Khare, Pratyush, Daphal, Pratap, Gese, Helmut

Assessment of the 50th Hybrid III Responses in Blunt Rear Impacts to the Torso

2021-01-091904/06/2021

Blunt impacts to the back of the torso can occur in vehicle crashes due to interaction with unrestrained occupants, or cargo in frontal crashes, or intrusion in rear crashes, for example. Six pendulum tests were conducted on the back of an instrumented 50th percentile male Hybrid III ATD (Anthropomorphic Test Device) to determine kinematic and biomechanical responses. The impact locations were centered with the top of a 15-cm diameter impactor at the T1 or at T6 level of the thoracic spine. The impact speed varied from 16 to 24 km/h. Two 24 km/h tests were conducted at the T1 level and showed repeatability of setup and ATD responses. The 16 and 24 km/h tests at T1 and T6 were compared. Results indicated greater head rotation, neck extension moments and neck shear forces at T1 level impacts. For example, lower neck extension was 2.6 times and 3.8 times greater at T1 versus T6 impacts at 16 and 24 km/h, respectively. A 24 km/h test at T1 was also conducted with a seatback attached to the

Buckman, Jennifer L., Parenteau, Chantal S., Burnett, Roger, Viano, David C., Andrecovich, Christopher

Pedestrian Impact Analysis of Side-Swipe and Minor Overlap Conditions

2021-01-088104/06/2021

This paper presents analyses of 21real-world pedestrian versus vehicle collisions that were video recorded from vehicle dash mounted cameras or surveillance cameras. These pedestrian collisions have in common an impact configuration where the pedestrian was at the side of the vehicle, or with a minimal overlap at the front corner of the vehicle (less than one foot overlap). These impacts would not be considered frontal impacts [1], and as a result determining the speed of the vehicle by existing methods that incorporate the pedestrian travel distance post impact, or by assessing vehicle damage, would not be applicable. This research examined the specific interaction of non-frontal, side-impact, and minimal overlap pedestrian impact configurations to assess the relationship between the speed of the vehicle at impact, the motion of the pedestrian before and after impact, and the associated post impact travel distances. The21analyzed events are categorized according to the type of impact

Neale, William T., Danaher, David, Donaldson, Andrew, Smith, Tegan

Occupant Restraint Dynamic System Evaluation - Frontal Impact Heavy Trucks

J2418_202011 (Current)

11/09/2020

This SAE Recommended Practice describes the test procedures for conducting frontal impact restraint tests for heavy truck applications. Its purpose is to establish recommended test procedures that will standardize restraint system testing for heavy trucks. Descriptions of the test set-up, test instrumentation, photographic/video coverage, and the test fixtures are included.

Truck Crashworthiness Committee

Frontal Crash Worthiness Performance of Bitubular Corrugated Conical Structures under both axial and oblique loads at low velocity

2020-01-098304/14/2020

Vehicle collisions are a major concern in the modern automotive industry. To ensure the passenger safety, major focus have been given on energy absorption pattern during collision, which lead to the implementation of new design of the crash box for low speed collision. The main aim of this research is optimization of the conical shaped bitubular structure based on its mean diameter, graded thickness and semi vertical angle. Further to increase energy absorption characteristics of the conical crash box, corrugations are integrated on both tubes and optimized based on different parameters such as number of corrugations, pattern of corrugation relative to both tubes and depth of corrugation. A finite element model is created to perform parametric study on corrugated conical bitubular structure based on axial and oblique load conditions at low velocity. Optimization to maximize total absorbed energy and minimize peak impact load on the crash box within constraints is conducted. The result

Porwal, Akash, Tripathi, Abhishek, Krishnasamy, Prabu

A Human Body Model Study on Restraints for Side-Facing Occupants in Frontal Crashes of an Automated Vehicle

2020-01-098004/14/2020

This study is to investigate kinematics and responses of side-facing seated occupants in frontal crashes of an automated minivan using Global Human Body Models Consortium (GHBMC) simplified occupant models (50th%ile male and 5th%ile female), and to develop new restraint concepts to protect the occupants. The latest GHBMC M50-OS and F05-OS models (version 2.1) were further validated with the Postmortem Human Subject (PMHS) side sled tests [Cavanaugh 1990] and the PMHS far-side sled tests [Formen 2013], with detailed correlations of the kinematics and the injury measures. Robustness and biofidelity of the GHBMC human models, especially for the pelvis and knee body regions, were further improved. Using the improved M50-OS and F05-OS models, we evaluated the body kinematics and injury measures of the side-facing seated occupants in frontal crashes at severities ranging from 15 mph to 35 mph. Three restraint conditions were studied: 1) no restraint; 2) lap belt only; 3) lap belt and

Zhao, Jay Zhijian, Katagiri, Maika, Decker, William, Lee, Sungwoo, Gayzik, Francis

Update on Second-Row Children Responses in Rear and Frontal Crashes with a Focus on the Potential Effect of Stiffening Front Seat Structures

2020-01-121504/14/2020

The protection of children in rear seats is an important issue, but it is a more complex than assessing front seat performance in rear impacts. 1997–2015 NASS-CDS data were analyzed to estimate the distribution and risk of seriously-to-fatally (MAIS 3+F) injured 0-7 year old children in the 2nd row by crash types with 1994+ model year vehicles. The results showed that children were frequently injured in frontal (39.3%) and in side (27.2%) crashes. The injury risk was highest in rollover (1.72% ± 0.36) followed by rear crashes (0.75% ± 0.56%). Individual rear and frontal impact cases were also reviewed to better understand injury mechanisms of children in the 2nd row. The cases were downloaded and reviewed. There were 15 injured children involved in 14 rear impact crashes. Half were associated with significant intrusion (12+ inches) intrusion of their seating area, pushing the child forward. More than half (7 out of 11 cases with known information) of the front seatbacks remained in

Parenteau, Chantal, Viano, David

Seat Performance and Occupant Moving Out of the Shoulder Belt in ABTS (All-Belts-to-Seat) in Rear Impacts

2019-01-103104/02/2019

This study examined occupant and seat responses with ABTS (all-belts-to-seat) in rear end collisions. Some have claimed improved ABTS seat performance and retention in rear impacts than conventional seats. ABTS seats tend to have higher ultimate yield strengths than conventional yielding seats. Most ABTS seats have asymmetric seatback stiffness due to the need for additional structure on one side of the seat to support shoulder belt loads. Many designs use a single-side recliner and single stanchion that anchors the D-ring. This asymmetry results in twisting of the seatback in severe rear impacts. Seatback twist can allow the occupant to move away from the shoulder belt. Rearward pull tests on ABTS seats also demonstrates seatback twisting and in some cases large drops in load during the test. The added strength and stiffness of ABTS seats lead to designs that are vulnerable to sudden force drops from separated parts.

White, Samuel, Viano, David, Burnett, Roger

Comparative Responses of the PIPER 6YO Human Body Model and the Q6 ATD for Simulated Frontal and Lateral Impacts

SC18-22-000611/12/2018

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

AV testing is for DUMMIES

18AUTP11_1211/01/2018

Rapid development of automated vehicles is driving ATD innovations, as Humanetics' CEO explains. A few years ago, Chris O'Connor started to notice a common talking point emerging from within the many autonomous vehicle conferences and meetings he was attending. “It seemed that many people in the industry, and those in Congress, were saying: ‘With autonomous cars, we won't have traffic accidents anymore,’” noted O'Connor, the CEO of Humanetics Innovative Solutions, the leading developer of anthropomorphic test devices (ATDs), commonly known as crash-test dummies. “And since there won't be crashes, we will no longer have to worry about occupant safety,” he recalled many pronouncing.

Brooke, Lindsay

Validation of Crush Energy Calculation Methods for Use in Accident Reconstructions by Finite Element Analysis

09-06-02-000910/04/2018

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

Numata, Shusuke, Mizuno, Koji, Ito, Daisuke, Okumura, Dai

Autonomous vehicles present passive-safety challenges

18AUTP10_0810/01/2018

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.

Optimizing Occupant Restraint Systems for Tactical Vehicles in Frontal Crashes

2018-01-062104/03/2018

The objective of this study was to optimize the occupant restraint systems for a light tactical vehicle in frontal crashes. A combination of sled testing and computational modeling were performed to find the optimal seatbelt and airbag designs for protecting occupants represented by three size of ATDs and two military gear configurations. This study started with 20 sled frontal crash tests to setup the baseline performance of existing seatbelts, which have been presented previously; followed by parametric computational simulations to find the best combinations of seatbelt and airbag designs for different sizes of ATDs and military gear configurations involving both driver and passengers. Then 12 sled tests were conducted with the simulation-recommended restraint designs. The test results were further used to validate the models. Another series of computational simulations and 4 sled tests were performed to fine-tune the optimal restraint design solutions. The sled tests with the

Hu, Jingwen, Ritchie Orton, Nichole, Chen, Cong, Reed, Matthew, Rupp, Jonathan, Gruber, Rebekah, Clark, David, Scherer, Risa

2019 Acura RDX brings world's-first chassis tech

18AUTP08_0901/01/2018

Few words are as inspiring to an engineering team as “all-new.” For the 2019 Acura RDX, the engineers behind the compact SUV's third generation had a host of all-new to manage, including a dedicated platform, five-link rear suspension, torque-vectoring driveline and infotainment interface. Though the turbocharged engine/10-speed transmission combo have recently appeared in other products, the RDX is its first all-wheel-drive (AWD) application.

Seredynski, Paul

Application of Extreme Value Theory to Crash Data Analysis

2017-22-001111/13/2017

A parametric model obtained by fitting a set of data to a function generally uses a procedure such as maximum likelihood or least squares. In general this will generate the best estimate for the distribution of the data overall but will not necessarily generate a reasonable estimation for the tail of the distribution unless the function fitted resembles the underlying distribution function. A distribution function can represent an estimate that is significantly different from the actual tail data, while the bulk of the data is reasonably represented by the central part of the fitted distribution. Extreme value theory can be used to improve the predictive capabilities of the fitted function in the tail region. In this study the peak-over-threshold approach from the extreme value theory was utilized to show that it is possible to obtain a better fit of the tail of a distribution than the procedures that use the entire distribution only. Additional constraints, on the current use of the

Xu, Lan, Nusholtz, Guy

An Assessment of Inflatable Seatbelt Interaction and Compatibility with Rear-Facing-Only Child Restraint Systems

2017-01-144503/28/2017

Ford Motor Company introduced the inflatable seatbelt system in 2011 and the system is now available in the second row of several Ford and Lincoln models. An important consideration is the interaction of the inflatable seatbelt system with child restraint systems (CRS). A comprehensive series of frontal impact sled tests, using a standardized test method, was conducted to compare the performance of rear-facing-only CRS installed using an inflatable seatbelt to the same CRS installed using a standard seatbelt. CRS models from several manufacturers in the North American market were tested both with and without their bases. CRABI 12 month old or Hybrid III 3 year old anthropomorphic test devices (ATD) were restrained in the CRS. The assessment included the ability to achieve a satisfactory installation with the inflatable seatbelt, comparisons of ATD and CRS kinematics, CRS system integrity, and comparisons of ATD responses. In all cases, acceptable installations of the CRS were achieved

Pline, Kevin, Board, Derek, Muralidharan, Nirmal, Sundararajan, Srinivasan, Eiswerth, Eric, Salciccioli, Katie, Baker, Noelle

Analysis of Driver Kinematics and Lower Thoracic Spine Injury in World Endurance Championship Race Cars during Frontal Impacts

2017-01-143203/28/2017

This study used finite element (FE) simulations to analyze the injury mechanisms of driver spine fracture during frontal crashes in the World Endurance Championship (WEC) series and possible countermeasures are suggested to help reduce spine fracture risk. This FE model incorporated the Total Human Model for Safety (THUMS) scaled to a driver, a model of the detailed racecar cockpit and a model of the seat/restraint systems. A frontal impact deceleration pulse was applied to the cockpit model. In the simulation, the driver chest moved forward under the shoulder belt and the pelvis was restrained by the crotch belt and the leg hump. The simulation predicted spine fracture at T11 and T12. It was found that a combination of axial compression force and bending moment at the spine caused the fractures. The axial compression force and bending moment were generated by the shoulder belt down force as the driver’s chest moved forward. The axial compression force at the spine was also induced by

Katsuhara, Tadasuke, Takahira, Yoshiki, Hayashi, Shigeki, Kitagawa, Yuichi, Yasuki, Tsuyoshi

Occupant Injury Response Prediction Prior to Crash Based on Pre-Crash Systems

2017-01-147103/28/2017

Occupant restraint systems are developed based on some baseline experiments. While these experiments can only represent small part of various accident modes, the current procedure for utilizing the restraint systems may not provide the optimum protection in the majority of accident modes. This study presents an approach to predict occupant injury responses before the collision happens, so that the occupant restraint system, equipped with a motorized pretensioner, can be adjusted to the optimal parameters aiming at the imminent vehicle-to-vehicle frontal crash. The approach in this study takes advantage of the information from pre-crash systems, such as the time to collision, the relative velocity, the frontal overlap, the size of the vehicle in the front and so on. In this paper, the vehicle containing these pre-crash features will be referred to as ego vehicle. The information acquired and the basic crash test results can be integrated to predict a simplified crash pulse. The injury

Luo, Xiao, Du, Wenjing, Li, Hao, LI, Peiyu, Ma, Chunsheng, Xu, Shucai, Zhang, Jinhuan

Influence of Honeycomb Cellular Meso-structure on Frontal Crash Analysis for Passenger Vehicle

2017-01-130103/28/2017

Frontal collisions account for majority of car accidents. Various measures have been taken by the automotive OEMs’ with regards to passive safety. Honeycomb meso-structural inserts in the front bumper have been suggested to enhance the energy absorption of the front structure which is favorable for passive safety. This paper presents the changes in energy absorption capacity of hexagonal honeycomb structures with varying cellular geometries; under frontal impact simulations. Honeycomb cellular metamaterial structure offers many distinct advantages over homogenous materials since their effective material properties depend on both, their constituent material properties and their cell geometric configurations. The effective static mechanical properties such as; the modulus of elasticity, modulus of rigidity and Poisson’s ratio of the honeycomb cellular meso-structures are controlled by variations in their cellular geometry. While the crushing responses in terms of energy absorption and

Patil, Deepak A., Buddhe, Hrishikesh

Study of an Enhanced Body of Small Vehicle in Frontal Crash Test and IIHS Small Overlap Test

2017-01-146803/28/2017

Previous work identified a relationship between vehicle drop and dummy injury under the high-speed frontal impact condition [1]. The results showed that vehicle drop greater than 60mm made the dummy injury worse. Moreover, that work identified the front side member as the crucial part affecting the vehicle drop. In this study, the body structure mechanism was studied to reduce vehicle drop by controlling the front side member, shotgun, and A-pillar. By analyzing full vehicles, it was recognized that the arch shape of the front side member was very important. Furthermore, if the top of the arch shape of front side member, shotgun, and A-pillar were connected well, then the body deformation energy could lift the lower part of A-pillar, effectively reducing vehicle drop. This structure design concept is named “Body Lift Structure” (BLS). The BLS was applied to B and C segment platforms. Additionally, a “Ring” shape was defined by the front side member, dash panel, and A-pillar. The BLS

Truck Deformation Classification

J1301_201702 (Historical)02/23/2017

The scope and purpose of this SAE Recommended Practice is to provide a classification system for deformation sustained by trucks involved in collisions on the highway. Application of the document is limited to medium trucks, heavy trucks, and articulated combinations.1 The TDC classifies collision contact deformation, as opposed to induced deformation, so that the deformation is segregated into rather narrow limits or categories. Studies of collision deformation can then be performed on one or many data banks with assurance that data under study are of essentially the same type.2 Many of the features of the SAE J224 MAR80 have been retained in this document, although the characters within specific columns vary. Each document must therefore be applied to the appropriate vehicle type. It is also important to note that the Truck Deformation Classification (TDC) does not identify specific vehicle configurations and body types. The TDC is an expression, useful to persons engaged in vehicle

Data Collection and Archiving Standards Committee

Collision Deformation Classification

J224_201702 (Historical)02/23/2017

The purpose and scope of this SAE Recommended Practice is to provide a basis for classification of the extent of vehicle deformation caused by vehicle accidents on the highway. It is necessary to classify collision contact deformation (as opposed to induced deformation) so that the accident deformation may be segregated into rather narrow limits. Studies of collision deformation can then be performed on one or many data banks with assurance that the data under study are of essentially the same type.1 The seven-character code is also an expression useful to persons engaged in automobile safety, to describe appropriately a field-damaged vehicle with conciseness in their oral and written communications. Although this classification system was established primarily for use by professional teams investigating accidents in depth, other groups may also find it useful. The classification system consists of seven characters, three numeric, and four alphameric, arranged in a specific order. The

Data Collection and Archiving Standards Committee

Occupant Restraint System Evaluation - Frontal Impact System-Level Heavy Trucks

J2419_201701 (Current)01/18/2017

This SAE Recommended Practice describes the test procedures for conducting frontal impact restraint system tests for heavy truck applications. Its purpose is to establish recommended test procedures that will standardize restraint system testing for heavy trucks. Descriptions of the test set-up, test instrumentation, photographic/video coverage, and the test fixtures are included.

Truck Crashworthiness Committee

Methodology to Derive National Estimates of Injuries and Fatalities in Road Traffic Crashes in India

2017-26-001601/10/2017

The Road Accident Sampling System - India (RASSI) accident database being developed by an international consortium of manufacturers and safety researchers is currently India’s only source of in-depth crash data. The database includes information on accident, vehicle, and driver factors associated with each crash, which is collected through on-scene crash investigations conducted by trained crash investigators, from four key sample regions (Coimbatore, Pune, Ahmedabad, and Kolkata). As the RASSI database continues to grow, the next step is to ensure that the sample data can be reliably extrapolated to the whole of India. This paper is an initial attempt to develop national estimates by crash type based on a few sampling locations currently being investigated by the RASSI teams in India. RASSI data was treated as a stratified sample of Indian accidents, and the locations, where the crash data is being collected, were considered as primary sampling units. The “mark and recapture

Padmanaban, Jeya, Ravishankar, R., Dandapani, Ajit

Ambulance Litter Integrity, Retention, and Patient Restraint

J3027_201611 (Historical)11/01/2016

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

Occupant Restraint and Equipment Mounting Integrity – Frontal Impact Ambulance Patient Compartment

J2917_201608 (Historical)08/17/2016

This SAE Recommended Practice describes the test procedures for conducting frontal 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

Uncertainty Assessment in Restraint System Optimization for Occupants of Tactical Vehicles

2016-01-031604/05/2016

We have recently obtained experimental data and used them to develop computational models to quantify occupant impact responses and injury risks for military vehicles during frontal crashes. The number of experimental tests and model runs are however, relatively small due to their high cost. While this is true across the auto industry, it is particularly critical for the Army and other government agencies operating under tight budget constraints. In this study we investigate through statistical simulations how the injury risk varies if a large number of experimental tests were conducted. We show that the injury risk distribution is skewed to the right implying that, although most physical tests result in a small injury risk, there are occasional physical tests for which the injury risk is extremely large. We compute the probabilities of such events and use them to identify optimum design conditions to minimize such probabilities. We also show that the results are robust to various

Drignei, Dorin, Mourelatos, Zissimos, Kosova, Ervisa, Hu, Jingwen, Reed, Matthew, Rupp, Jonathan, Gruber, Rebekah, Scherer, Risa

Uncertainty Optimization of Thin-walled Beam Crashworthiness Based on Approximate Model with Step Encryption Technology

2016-01-040404/05/2016

Crashworthiness is one of the most important performances of vehicles, and the front rails are the main crash energy absorption parts during the frontal crashing process. In this paper, the front rail was simplified to a thin-walled beam with a cross section of single-hat which was made of steel and aluminum. And the two boards of it were connected by riveting without rivets. In order to optimize its crashworthiness, the thickness (t), radius (R) and the rivet spacing (d) were selected as three design variables, and its specific energy absorption was the objective while the average impact force was the constraint. Considering the error of manufacturing and measurements, the parameters σs and Et of the steel were selected as the uncertainty variables to improve the design reliability. The algorithm IP-GA and the approximate model-RBF (Radial Basis Function) were applied in this nonlinear uncertainty optimization. In order to improve the accuracy of the RBF model, a new step-encryption

Comparison of the Accuracy and Sensitivity of Generation 1, 2 and 3 Toyota Event Data Recorders in Low-Speed Collisions

2016-01-149404/05/2016

The accuracy of the speed change reported by Generation 1 Toyota Corolla Event Data Recorders (EDR) in low-speed front and rear-end collisions has previously been studied. It was found that the EDRs underestimated speed change in frontal collisions and overestimated speed change in rear-end collisions. The source of the uncertainty was modeled using a threshold acceleration and bias model. This study compares the response of Generation 1, 2 and 3 Toyota EDRs from Toyota Corolla, Camry and Prius models. 19 Toyota airbag control modules (ACMs) were mounted on a linear sled. The ACMs underwent a series of frontal and rear-end haversine crash pulses of varying severity, duration and peak acceleration. The accuracy and trigger thresholds of the different models and generations of EDRs were compared. There were different accuracy trends found between the early Generation 1 and the more modern Generation 2 and 3 EDRs. There were also differences found in the threshold and trigger

Xing, Peter, Lee, Felix, Flynn, Thomas, Wilkinson, Craig, Siegmund, Gunter

Alternative Approaches to Occupant Response Evaluation in Frontal Impact Crash Testing

2016-01-154004/05/2016

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

Crashworthiness Design of Automotive Body in White using Topology Optimization

2016-01-153504/05/2016

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

Tian, Linli, Gao, Yunkai

Uncertainty Assessment in Restraint System Optimization for Occupants of Tactical Vehicles

2016-01-0316-TEST-REC04/05/2016

We have recently obtained experimental data and used them to develop computational models to quantify occupant impact responses and injury risks for military vehicles during frontal crashes. The number of experimental tests and model runs are however, relatively small due to their high cost. While this is true across the auto industry, it is particularly critical for the Army and other government agencies operating under tight budget constraints. In this study we investigate through statistical simulations how the injury risk varies if a large number of experimental tests were conducted. We show that the injury risk distribution is skewed to the right implying that, although most physical tests result in a small injury risk, there are occasional physical tests for which the injury risk is extremely large. We compute the probabilities of such events and use them to identify optimum design conditions to minimize such probabilities. We also show that the results are robust to various

Drignei, Dorin, Mourelatos, Zissimos, Kosova, Ervisa, Hu, Jingwen, Reed, Matthew, Rupp, Jonathan, Gruber, Rebekah, Scherer, Risa

Crash testing advances on many fronts

16MEIP03_1803/01/2016

Traffic fatalities have declined significantly over the last several years, but the U.S. is on track to have its deadliest year since 2007, according to the National Safety Council. That's shining the spotlight on crash testing, which helps automakers create the safest vehicles possible. Crash-testing research being done by testing groups and tool developers is extending its reach to crash avoidance. Some of the latest developments in collision avoidance and protection were recently explored by four industry experts in “The Future of Crash Testing” Technical Webinar Series from the Editors of SAE, which is now available for on-demand viewing.

Optimization of Seatbelt Anchorage Mount Locations for Occupant Injury Reduction in Frontal Crash

2016-28-025102/01/2016

In the event of a frontal car crash, occupant sitting in a car meets various types of injuries like Head injury, Chest compression, Neck injury etc. These injuries may lead to the death of an occupant if exceeded beyond biomechanical limits. Seat belt is a primary restraint system, which when worn controls the motion of occupant sitting inside the car during the event of a car crash. An Anchorage location of three point seat belt system has significant effect on occupant injuries during the crash event. By changing the mount locations of a seat belt anchor points i.e. D-ring, Anchor & Buckle, performance of seatbelt system can be enhanced further thereby reducing occupant injuries to certain extent. As per regulation AIS015, locations of safety belt anchorage points should be within prescribed zone. This paper explains effect of changing mounting location of each anchorage points on occupant injuries & also explains how to find optimized seat belt anchorage mount locations within

Patil, Kantilal, Reddy, Siva, Zafar, Nadeem

Effects of Excitation Voltage on Piezoresistive and Resistive Sensor Output Characteristics

2016-28-018202/01/2016

In laboratory car crash tests, Anthropomorphic Test Devices (ATD) are equipped with piezoresistive and resistive sensors for occupant injury assessment. Accelerometers are inertial transducers that convert acceleration into electrical output which can be easily recorded by a Data Acquisition System (DAS). For an accelerometer, this electrical output mainly depends upon subjected acceleration, sensitivity of the accelerometer, excitation voltage and gain provided. Before use in testing, accelerometers are calibrated at a standard excitation (manufacturer decided) voltage to determine characteristics like Sensitivity, Sensitivity per unit excitation voltage, Zero Measurand Output (ZMO), Transverse Sensitivity etc. It is observed that these characteristics are highly dependent on the excitation voltage. In testing, due to limitations of DAS and/or other unwanted noise in the excitation voltage, these accelerometers are sometimes used at a different excitation voltage. This paper studies

Reddy, Indrakaran, Singh, Niraj Kumar, Singh, Sonu Kumar

Lighter, more powerful 2016 Honda Pilot

15AUTP10_0210/01/2015

The third-generation SUV gets a sleek new look and plenty of slick technology for enhanced performance and safety. Programs for new re-engineered vehicles pose a great challenge for the engineers and other professionals assigned to them: load the vehicle with more advanced technology, consumer-friendly amenities, and safety features required to meet stringent requirements, all while trimming weight from any area necessary to maintain-or ideally decrease-overall weight compared to the previous generation. The 2016 Honda Pilot development team, faced with said challenge, succeeded brilliantly. The new three-row SUV is 289 lb (131 kg) lighter-the previous Pilot Touring weighed 4632 lb (2101 kg) vs. the new Pilot Elite, which includes more features but weighs 4343 lb (1970 kg)-while recently earning a 2015 Top Safety Pick+ rating from the Insurance Institute for Highway Safety (IIHS).

Finite Element Analysis and Validation of Bus Seat Structure as per AIS023: Safety Features Evaluation of Bus Seat using Hybrid III Dummy

2015-01-286909/29/2015

Buses are always one of the main and favorite sources of public transit. Thousands of people die or injure every year in bus accidents. Bus seat can also cause severe injury to the occupants in case of frontal impact. Seat structure of the bus should absorb sufficient energy to minimize the passenger injury. Most of the occupants seated in the second row or further back were injured by hitting the seat back in the row in front of them. In India, AIS023 (Automotive Industry Standards) is one of the several mandatory standards from CMVR (Central Motor Vehicles Rules) to ensure the seat strength and occupant safety during accidents. This standard specifies minimum and maximum deformations range for the seat back to minimize the passenger injury with adequate seat strength. Present study includes the Finite Element Analysis (FEA) and correlation of bus seat as per AIS023 test setup with LS-Dyna explicit tool. Reasonable correlation was found between test and simulation results. This

Sharma, Sumit, Sharma, Sandeep, Gupta, Umashanker, Joshi, Ravi, Pawar, Shailesh

Driver Restraint System Optimization for Vehicle Frontal Impact

2015-36-026309/22/2015

In 2010, the UN General Assembly proclaimed the period 2011-2020 as the Decade of Action for Road Safety, with a goal to stabilize and then reduce the forecast level of road traffic fatalities around the world. Road traffic accidents are the 8th cause of death in Brazil, according to World Health Rankings. There are few studies around the world with respect to cost due to traffic accidents, however a study performed in 2011 estimates that were spent R$ 44.6 billion in Brazil. So, the recent Brazilian regulations updates have enforced the automakers to develop vehicles safer to passengers and pedestrians. These regulations focus on prevent, reduce or minimize the traumas and injuries caused by different types of vehicular accidents. The present work was developed to optimize the driver restraint system, while focusing on minimizing the trauma during a vehicle frontal impact. The driver restraint system was optimized considering the complex interaction between the ATD and the different

de Lima, Anderson, Almeida, Eduardo L., Gouvea, Marco A.

Occupant Restraint Dynamic System Evaluation - Frontal Impact Heavy Trucks

J2418_201508 (Historical)

08/27/2015

This SAE Recommended Practice describes the test procedures for conducting frontal impact restraint tests for heavy truck applications. Its purpose is to establish recommended test procedures that will standardize restraint system testing for heavy trucks. Descriptions of the test set-up, test instrumentation, photographic/video coverage, and the test fixtures are included.

Truck Crashworthiness Committee

Improved Seat Belt Restraint Geometry for Frontal, Frontal Oblique and Rollover Incidents

2015-01-074004/14/2015

Throughout the first decade of the twenty first century, large improvements in occupant safety have been made in NASCAR®'s (National Association for Stock Car Auto Racing, Inc) race series. Enhancements to the occupant restraint system include the development and implementation of head and neck restraints, minimum performance requirements for belts and seats and the introduction of energy absorbing foam are a few highlights, among others. This paper discusses nineteen sled tests used to analyze hypothesized improvements to restraint system mounting geometry. The testing matrix included three sled acceleration profiles, three impact orientations, two Anthropomorphic Test Device (ATD) sizes as well as the restraint system design variables.

Patalak, John, Gideon, Thomas, Melvin, John W., Rains, Mike

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