Browse Topic: Occupant protection

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Novel Method for Vehicle Crash Pulse prediction2024-26-000201/16/2024
Airbags are crucial elements of passive safety in vehicles that help minimizing occupant injuries during various crash scenarios such as frontal, side, and oblique impacts. Airbags in cars are now mandatory in many countries, and their performance depends on how well the system is designed. A well-tuned airbag deployment algorithm is necessary to score superior NCAP safety ratings. Tuning of airbag deployment algorithms requires several data points which are obtained through actual crash testing. This is a cumbersome and expensive process as it involves crash tests for each scenario (e.g., full front barrier, offset deformable barrier, angled impact, etc.) at multiple test speeds. These tests are destructive and render the vehicles only worthy of scrap. The data gathered from various sensors (acceleration, pressure, etc.) is used to develop robust vehicle model specific algorithms that must correctly identify the crash scenario and send airbag firing signal at the optimal pre-decided
Kumar, Ayush
Auto lock of manual seat track adjustment in passenger vehicles2024-26-000101/16/2024
Vehicle seats are provided with a facility to adjust the seat forward or rearward. Seating positions can be adjusted according to the comfort of the occupants. Seat track position plays an important role in airbag deployment during vehicle crash. A hand lever is used to manually adjust the seat track in some vehicles by pulling up the lever and releasing it after the appropriate seating position has been adjusted. All the safety manuals provided by OEMs warns about the adjustment of seat track position as forward or rearward during vehicle movement. It is high risk because of any rapid movements due to unexpected road conditions might result in driver losing control of the pedals and steering wheel and this may leads to severe injuries and even can cause fatalities. The proposed system in this paper is focused to provide more safety to the driver with a new method " Auto lock of manual seat track adjustment in passenger vehicles”. The proposed system shall be integrated with Body
Nalagatla, Karthik, S, Deepak Kumar, Jamadar, Tohidanjum
Importance of Pole Side Impact Test for Assessment of Curtain Airbags2024-26-001901/16/2024
Government of India, in 2017, mandated a Side Impact Test (AIS 099 technically aligned to UN ECE Regulation No. 95.03 series of amendments) on M1 category Passenger Vehicles to ensure protection of occupants in lateral impact accident scenarios. Later, in 2022, a draft notification has been issued by the Government mandating installation of 6 airbags (2 No.of thorax side airbags, 2 No. of head protection or curtain airbags in addition to already mandated installation of Driver and Passenger Airbags) in all such passenger vehicles. However, the vehicles fitted with side thorax airbag and curtain airbags are proposed to be assessed as per AIS099 test only. Curtain Airbags are typically installed to protect occupant’s head from severe injuries in narrow object impacts simulated in Pole Side Impact Test Configurations. However, at present, India has not notified an equivalent standard to UN R135 demanding performance of the vehicle in pole side impact scenarios. Typically, OEMs may need to
Jaju, Divyan, Kulkarni, Dileep, Mahindrakar, Rahul, Mahajan, Rahul
PERFORMANCE OF FIVE-POINT SEAT BELT ON OCCUPANT SAFETY IN VEHICLE ON FRONTAL CRASH TEST2022-28-049311/18/2022
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
A Study of High Refinement Simulation Prediction on the CAB Development for FMVSS226 Ejection Mitigation Performance2022-01-092203/29/2022
In the side impact crash accident, the curtain airbag (CAB) plays a significant role in the occupant head protection. With the increasing of the rollover accidents, the CAB development is requested to be able to protect the occupant head throughout the whole rollover accident, and to ensure that the occupant head is not partially or totally ejected from the vehicle. NHTSA released the FMVSS226 Standard in 2011, defined the requirements for ejection mitigation systems, which limits the linear travel of headform by 100mm. In China regulations, there are similar requirements starting in 2021. The difference is that it can be replaced by meeting the pressure holding requirements of 6s (up to 50% of the average pressure of 40-70ms). Therefore, on the basis of the existing airbag design, adding the rollover protection function becomes a new challenge for the airbag development. During the development of the curtain airbag, the cushion design, inflator type, and the fold pattern, all have an
Shan, Jinhui, Xue, Lele, Wang, Cheng
Reconstruction of an auto-rickshaw frontal crash using FE simulation with validation using captured crash video from India2021-28-025710/01/2021
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
Seat Design Parameters and Its Influence on Performance Metrics of FMVSS 202a Back Set Retention Test2021-01-092704/06/2021
Automotive Seat design is driven by various design factors considering occupant safety, occupant comfort, road visibility etc. Seats are generally a combination of structural frames, foams, suspension wires, adjustment mechanisms etc. to support safety, comfort & road visibility. Most of the regulatory tests on seats are related to safety which demands structural integrity of seat frames, welds and bolts etc. And few tests demand occupant comfort and seat functionality involving foams, suspension wires & adjustment mechanisms. There are few tests which needs design consideration on all seat components discussed above. FMVSS 202a Back Set Retention is one among them. It is a static test with multiple loads in sequence of loading and unloading steps on the seat back and head restraint. Stiffness of the foams, lumbar mats, seat adjustment mechanisms, seat frames contribute a lot to meet performance targets set by the regulation. This technical paper discusses various design factors, their
Purnoo Munuswamy, Ravi, ThamnampudiI, Ramasubba Reddy, Shanmugam, Seenuvasan, Muthupandian, Arunachalam, Holur, Prabhu
Seat Performance in Rear Impacts: Seatback Deflection and Energy Dissipation2021-01-091604/06/2021
Occupant protection in rear crashes is complex. While seatbelts and head restraints are effective in rear impacts, seatbacks offer the primary restraint component to front-seat occupants in rear impacts. Seatback deflection due to occupant loading can occur in a previous rear crash and/or in multiple-rear event crashes. Seatback deflection will in-turn affect the plastic seatback deformation and energy absorption capabilities of the seat. This study was conducted to provide information on seatback deflection and seat energy consumption in low and high-speed rear impacts. The results can be used to examine seatback deflection and energy consumed in a previous rear impact, or in collisions with multiple rear impacts. Prior seatback deflection and energy absorption can affect the total remaining energy absorption and seat performance for a subsequent rear impact. Rear sled tests included eight 16 km/h tests conducted with the BioRID and eight matched 40 km/h tests with the 50th percentile
White, Samuel, Parenteau, Chantal, Burnett, Roger
Effect of ATD Size, Vehicle Interior and Restraint Misuse on Second-Row Occupant Kinematics in Frontal Sled Tests2021-01-091404/06/2021
Interest in rear-seat occupant safety has increased in recent years. Information relevant to rear-seat occupant interior space and kinematics are needed to evaluate injury risks in real-world accidents. This study was conducted to first assess the effect of size and restraint conditions, including belt misuse, on second-row occupant kinematics and to then document key clearance measurements for an Anthropomorphic Test Device (ATD) seated in the second row in modern vehicles from model years 2015-2020. Twenty-two tests were performed with non-instrumented ATDs; three with a 5th percentile female Hybrid III, 10 tests with a 10-year-old Hybrid III, and 9 tests with a 6-year-old Hybrid III. Test conditions included two sled bucks (mid-size car and sport utility vehicle (SUV)), two test speeds (56 and 64 km/h), and various restraint configurations (properly restrained and improperly restrained configurations). Head and knee trajectories were assessed. Head excursion was 38 percent greater
Parenteau, Chantal, Burnett, Roger, Danthurthi, Sri Sai Kameshwari, Andrecovich, Christopher
Incidence and Mechanism of Head, Cervical Spine, Lumbar Spine, and Lower Extremity Injuries for Occupants in Low- to Moderate-Speed Frontal Collisions2021-01-090204/06/2021
Automotive accidents and subsequent personal injury claims incur substantial costs annually. While three-point restraint usage, dual-stage airbags, and knee bolster and side curtain airbags have become more ubiquitous and, in some cases, governmentally mandated for front seat occupants, occupant safety and injury risk assessment continue to be at the forefront of automotive innovation. In this study, we combined analyses of the National Automotive Sampling System Crashworthiness Data System (NASS-CDS; 2007-2015) and the Crash Investigation Sampling System (CISS; 2017) with data acquired from vehicle-to-vehicle crash tests conducted with instrumented anthropomorphic test device (ATD) occupants. Together, these analyses were used to compare and relate field injury rates with potential injury mechanisms in low- to moderate-speed frontal collisions. First, low- to moderate-speed (delta-V ≤ 24 km/h) frontal crash data from NASS-CDS and CISS were analyzed to estimate the rate of AIS 2+ and
Davis, M., Mkandawire, C., Brown, T., Pasquesi, S.
Adapting to Manufacturing Challenges of COVID-19TBMG-3855502/01/2021
The COVID-19 pandemic has caused great changes and challenges, disrupting not only the global marketplace but also the supply chains that keep people and essential businesses healthy and functioning. For example, amid an already growing market for infection-control gear and hygienic products made of nonwoven thermoplastic fabrics, COVID-19 has greatly strained and helped to reshape the global supply chain for nonwoven personal protective equipment (PPE).
Editorial20AVEP05_0105/01/2020
Privately-owned vehicles were never so safe as they are today. Nor have they made so much sense. That thought hit me between the nostrils recently, as I sprayed a pungent disinfectant on the steering wheel of my family's B-segment runabout. Carefully wiping down the car's touch points with antibacterial cleaners has become a new pandemic ritual for us after returning home from food shopping and other essential missions. My little tribe generally keeps the interiors of our two vehicles tidy. Finding the occasional French fry buried in a seat track is, however, preferable to the dangerous microbes deposited every minute in the typical bus, train, or ride-share. The term “clean,” as understood by transit passengers, means a few spritzes by a custodial crew racing to meet uptime targets.
Brooke, Lindsay
Evaluation of Corpuscular Particle Method (CPM) in LS-DYNA for Airbag Modeling2020-01-097804/14/2020
This paper presents a systematic study to assess maturity of Corpuscular Particle Method (CPM) to accurately predict airbag deployment kinematics and its overall responses. The study was performed in three phases: (1) a correlation assessment of CPM predicted inflator characteristics to closed tank tests; (2) a correlation assessment of CPM predicted airbag deployment kinematics, airbag pressure, reaction force from a static deployment of a Driver Airbag (DAB) and (3) a correlation prediction of the impactor force by CPM versus impactor force from physical drop tower tests. These studies were repeated using the Uniform Pressure Method (UPM), to compare the numerical methods for their accuracy in predicting the physical test, computational cost, and applicability. Results from the study suggest that CPM satisfies the fundamental energy laws, and accurately captures the realistic airbag deployment kinematics, especially during the early deployment stage, unlike UPM. CPM accurately
Anantharaju, Neeharika, Uduma, Kalu, Shi, Yibing
Products of Tomorrow: February 2020TBMG-3596802/01/2020
This column presents technologies that have applications in commercial areas, possibly creating the products of tomorrow. To learn more about each technology, see the contact information provided for that innovation.
The Effects of Front-Mounted Accessories on Air Bag Sensors and CrashworthinessJ2431_201910 (Current)10/09/2019
Almost all light trucks now are being manufactured with at least a driver side air bag and all will have dual air bags by 1998. The driving forces behind this feature are occupant safety, federal regulations, and competition in the industry. Along with the booming popularity of pickups and SUVs, they are commonly accessorized with a wide variety of products. Many accessories for four-wheel drives in particular are mounted on the front of the vehicle. These products include grille/brush guards, winches, snow plows, replacement bumpers, bicycle carriers, etc. Concerns have arisen over the compatibility of these accessories with the vehicle’s air bag system. The vehicle manufacturers are concerned because of their huge investment in design and crash test verification of the complete vehicle system and keen awareness of the federal regulations. The crushability of the front bumper and supporting structure are key elements in the system, so alterations to that area become logical concerns
Motor Vehicle Council
The Navigator19AVEP05_0305/01/2019
Lessons from the 737 Max-8 Debacle It's always a tragedy when people die as a result of a machine malfunctioning. It's even more tragic if we fail to learn from that failure to make future machines safer. In recent months, two practically new Boeing 737 Max-8 jetliners have crashed claiming more than 300 lives. While we don't yet have the final results of the investigations, early indications point to new automation systems, the way they were validated, and the way operators were trained. As we rush headlong into the era of automated driving, this seems like a remarkably teachable moment.
Abuelsamid, Sam
Effects of Innovation in Automated Vehicles on Occupant Compartment Designs, Evaluation, and Safety: A Review of Public Marketing, Literature, and Standards2019-01-122304/02/2019
In recent years, the discussion around the advent of highly automated vehicles has shifted from “if” to “when.” Commercially available vehicles already incorporate automated vehicle (AV) technologies of varying capability, and the eventual transition to fully automated systems, at least within certain predefined Operational Design Domains, is largely considered inevitable. While the full ramifications of this shift and the eventual depreciation of human driver control are still under intense debate, there is broad agreement on one issue -the advent of driverless systems will remove several constraints on the design of vehicle interior spaces, creating the opportunity for innovation. Even at this early stage, ambitious design concepts of purpose specific vehicles - mobile gyms, offices, bedrooms - have been proposed. More grounded designs, such as rotating passenger seats, have also been put forward. However, there are two other points on which general agreement exists - future AVs will
Filatov, Anton, Scanlon, John M., Bruno, Alexander, Danthurthi, Sri Sai Kameshwari, Fisher, Jacob
A Software Tool for Injury Analysis of Blast and Crash Data2019-01-122504/02/2019
In recent years the U.S. Army Tank-Automotive Research, Development, and Engineering Center (TARDEC) has been investigating the survivability and injury mechanisms of underbody blast and crash, and their effects on personnel, with the use of Anthropomorphic Test Devices (ATD), or crash test dummies. Injury Assessment Reference Values (IARV) for crash have been researched for decades, and the US Army Research Laboratory (ARL), some years ago, also developed IARVs for underbody blast for the Hybrid III 50th percentile ATD. More recently, TARDEC extended these IARVs for the 5th and 95th percentile. With the advent of TARDEC’s Occupant Protection Laboratory large amounts of data were accumulated, which brought an interest in automating the analysis, and so a software tool was developed. The interactive in-house written software, called ICalc, allows the user to open test data files acquired from blast testing, drop tower testing, and crash testing. Data can be automatically bias corrected
Bryk, Darryl, Foster, Craig
Development of Parametrically Integrated Software Platform for Passenger Car Brake System2019-01-123104/02/2019
The hydraulic servo brake system for passenger car plays a central role in occupant protection, which directly affects the automotive active safety and road handling. In this paper, an integrated parameterized software platform of hydraulic servo brake systems is proposed to realize fast and efficient braking system development. At first, according to the structure and working principle of the hydraulic servo brake system, the relationship among amount of fluid required for brake caliper, pedal feel and performance of the brake system is analyzed. Then, based on kinematics and dynamics of the hydraulic servo brake system, a simulation model for analyze pedal feel and amount of fluid required for brake caliper is built in AMESim, which is composed of brake pedal, vacuum booster, brake master cylinder, brake hoses and brake calipers, etc. In addition, the accuracy of the simulation model is verified by bench tests, and the significantly influential factors on the amount of fluid required
Pan, Jin, Guo, Xuexun, Zhou, Wei, Pei, Xiaofei, Pan, Hao, Zhang, Jie
Evaluation of Occupant Loading in Low- to Moderate-Speed Frontal and Rear-End Motor Vehicle Collisions2019-01-122004/02/2019
Low- to moderate-speed motor vehicle collisions are common roadway occurrences that are generally associated with low rates of reported injury. While such complaints are generally infrequent, claims of injuries resulting from low- to moderate-speed motor vehicle collisions persist. A limited body of literature using quantitative techniques and full-scale crash tests is available to assess the injury potential associated with such collisions. Prior studies have analyzed occupant kinematics and kinetics as well as human injury risk in low- to moderate-speed collisions with older vehicle vintages but do not assess the effects of updated vehicle interior designs and occupant protection devices reflective of efforts to optimize occupant kinematics and reduce occupant loading and injury risk in more modern vehicles. This study was conducted to evaluate the injury potential for occupants of vehicles with modern design elements involved in low- to moderate-speed inline motor vehicle collisions
Toney-Bolger, Megan, Campbell, Ian, Miller, Bruce, Davis, Mathieu, Fisher, Jacob
Analysis of Rear Seat Sled Tests with the 5th Female Hybrid III: Incorrect Conclusions in Bidez et al. SAE 2005-01-17082019-01-061804/02/2019
Objective: Sled test video and data were independently analyzed to assess the validity of statements and conclusions reported in Bidez et al. SAE paper 2005-01-1708 [7]. Method: An independent review and analysis of the test data and video was conducted for 9 sled tests at 35 km/h (21.5 mph). The 5th female Hybrid III was lap-shoulder belted in the 2nd or 3rd row seat of a SUV buck. For one series, the angle was varied from 0, 15, 30, 45 and 60 deg PDOF. The second series involved shoulder belt pretensioning and other belt modifications. Results: Bidez et al. [7] claimed “The lap belts moved up and over the pelvis of the small female dummy for all impact angles tested.” We found that there was no submarining in any of the tests with the production lap-shoulder belts. Bidez et al. [7] claimed “H3-5F dummies began to roll out of their shoulder belt at… 30 degrees. Complete loss of torso support was seen at 45 degrees without significant kinetic energy dissipation.” We found that the
Viano, David, Parenteau, Chantal
The Effects of Inboard Shoulder Belt and Lap Belt Loadings on Chest Deflection2018-22-000211/12/2018
Chest injuries occur frequently in frontal collisions. During impact, tension in the lap belt is transferred to the inboard shoulder belt, which compresses the lower ribs of the occupant. In this research, inboard shoulder belt and lap belt geometries and forces were investigated to reduce chest deflection. First, the inboard shoulder belt geometry was changed by the lap/shoulder belt (L/S) junction for the rear seat occupant in sled tests using Hybrid III finite element simulation, sled tests and THOR simulation. As the L/S junction was closer to the ASIS (anterior superior iliac spine), chest deflection of the Hybrid III was smaller. The L/S junction around the ilium has the potential to reduce chest deflection without significant increase of head excursion. For THOR, although the chest deflection reduction effect due to closer L/S junction to the ASIS was observed, chest deflection was still substantially large since the lap belt overrode the ASIS. Second, measures to hook the ASIS
Mizuno, Koji, Yoshida, Ryoichi, Nakajima, Yutaka, Tanaka, Yoshihiko, Ishigaki, Ryota, Hosokawa, Naruyuki, Hitosugi, Masahito
Performance Standard for Passenger Smoke and Toxic Fumes Respiratory Protective EquipmentAS8048 (Historical)10/18/2018
This SAE Aerospace Standard (AS) defines the performance requirements for equipment to be used by untrained cabin occupants for protection from toxic and irritant atmospheres while on board and during evacuation of an aircraft.
A-10 Aircraft Oxygen Equipment Committee
Autonomous vehicles present passive-safety challenges18AUTP10_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.
Buchholz, Kami
Development of Component Level Transfer Equations of Simplified Human and ATD Occupant Models09-06-01-000506/05/2018
Safety systems have historically been evaluated with anthropomorphic test devices for research, development, or regulatory concerns. Human body models are another avenue for use in the investigation of occupant safety. In this study, transfer equations are developed to quantify the response of a human model (Global Human Body Models Consortium average male simplified model) and dummy model (Hybrid-III) in equivalent environments. Environments were selected based on certification test setups used for the Hybrid III ATD as well as a basic frontal sled environment. The tests include a head drop, neck flexion/extension, and chest and knee impacts. Furthermore, models were positioned within a simplified occupant interior for sled tests. In all, 30 matched pair simulations were run, 60 in total. Peak metrics between human and anthropomorphic test device models showed strong linear correlation in component testing however, as the complexity of the simulations increased, agreement tended to
Guleyupoglu, Berkan, Koya, Bharath, Gayzik, Francis Scott
Optimizing Occupant Restraint Systems for Tactical Vehicles in Frontal Crashes2018-01-062104/03/2018
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
A Fast Running Loading Methodology for Ground Vehicle Underbody Blast Events2018-01-062004/03/2018
A full-system, end-to-end blast modeling and simulation of vehicle underbody buried blast events typically includes detailed modeling of soil, high explosive (HE) charge and air. The complex computations involved in these simulations take days to just capture the initial 50-millisecond blast-off phase, and in some cases, even weeks. The single most intricate step in the buried blast event simulation is in the modeling of the explosive loading on the underbody structure from the blast products; it is also one of the most computationally expensive steps of the simulation. Therefore, there is significant interest in the modeling and simulation community to develop various methodologies for fast running tools to run full simulation events in quicker turnarounds of time. This paper discusses investigation of a fast running blast loading methodology wherein the effects of the soil can be adequately captured without having to employ a highly detailed and computationally intensive soil
Ramalingam, Jaisankar, Thyagarajan, Ravi
Using Shoulder Bolster and Knee Bolster to Achieve Protection Effect Comparable to Seatbelt and Airbag2018-01-117004/03/2018
Seatbelt and airbags provide effective occupant restraint, but are also potential to induce intrusive deformation and submarining injuries in motor vehicle crashes. To address these issues, this study puts forward a new restraint concept that applies restraint loads on shoulders and knees/femurs, i.e., the sturdiest regions of human body, via a combined use of shoulder bolster and knee bolster based on biomechanical computational analysis. The load characteristics of the two bolsters were optimized to obtain protection effectiveness superior to conventional use of seatbelt and airbag. Occupant kinematics and kinetics were taken into account, including the excursions of head, shoulders and knees, the accelerations of head and chest, and the compressions of thorax on several locations on the ribcage. The injury risk of rib fractures was monitored based on the strain levels of ribcage. Results show that applying adaptive restraint loads on the sturdy regions of human body using shoulder
Huang, Yuan, Zhou, Qing, Ji, Peijun, Nie, Bingbing
Stable and Accurate LS-DYNA Simulations with Foam Material Models: Optimization of Finite Element Model Parameters2017-01-133803/28/2017
Cellular foams have found a predominant application in automotive industry for efficient energy absorption so as to meet stringent and continuously improving vehicle crashworthiness and occupant protection criteria. The recent inclusion of pedestrian protection regulations mandate the use of foams of different densities for impact energy absorption at identified impact locations; this has paved the way for significant advancements in foam molding techniques such as dual density and tri-density molding. With increased emphasis on light-weighting, solutions involving the use of polymeric or metallic foams as fillers in hollow structures - foam encapsulated metal structures - are being explored. Another major automotive application of foams is in the seat comfort area, which again involves foams of intricate shapes and sizes. In addition, a few recently developed foams are anisotropic, adding on to the existing complexities. Complexities associated with controlled/ uncontrolled spatial
Ramaswamy, Karthik, Patham, Bhaskar, Savic, Vesna, Tripathy, Biswajit
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
Sanchez, Jacob, Malivern, Melcior, Parera, Núria, Fornells, Alba
A Semi-Automated Approach to Real World Motor Vehicle Crash Reconstruction Using a Generic Simplified Vehicle Buck Model2016-01-148804/05/2016
Computational finite element (FE) modeling of real world motor vehicle crashes (MVCs) is valuable for analyzing crash-induced injury patterns and mechanisms. Due to unavailability of detailed modern FE vehicle models, a simplified vehicle model (SVM) based on laser scans of fourteen modern vehicle interiors was used. A crash reconstruction algorithm was developed to semi-automatically tune the properties of the SVM to a particular vehicle make and model, and subsequently reconstruct a real world MVC using the tuned SVM. The required algorithm inputs are anthropomorphic test device position data, deceleration crash pulses from a specific New Car Assessment Program (NCAP) crash test, and vehicle interior property ranges. A series of automated geometric transformations and five LSDyna positioning simulations were performed to match the FE Hybrid III’s (HIII) position within the SVM to reported data. Once positioned, a baseline simulation using the crash test pulse was created. A Latin
Jones, Derek, Gaewsky, James, Weaver, Ashley, Stitzel, Joel
Preliminary study of uniform restraint concept for protection of rear-seat occupant under mid and high crash severities2016-01-152804/05/2016
As the restraint technologies for front-seat occupant protection advance, such as seatbelt pre-tensioner, seatbelt load limiter and airbag, relative effectiveness of rear-seat occupant protection decreases, especially for the elderly. Some occupant protection systems for front-seat have been proved to be effective for rear-seat occupant protection as well, but they also have some drawbacks. Seatbelt could generate unwanted local penetrations to the chest and abdomen. And for rear-seat occupants, it might be difficult to install airbag and set deployment time. For crash protection, it is desirable that the restraint loads are spread to the sturdy parts of human body such as head, shoulders, rib cage, pelvis and femurs, as uniformly as possible. This paper explores a uniform restraint concept aiming at providing protection in wide range of impact severity for rear-seat occupants. In this study, we use THUMS 50th percentile occupant model to simulate response under sled test frontal
Ji, Peijun, Zhou, Qing
Load-Limiters Effect on Occupant Restraint System Performance2016-01-150504/05/2016
This paper investigates the role that load-limiters play with respect to the performance of occupant protection systems, with focus on performance in frontal crashes. Modern occupant protection systems consist of not just the seat belt, but also airbags, interior vehicle surfaces and vehicle structure. Modern seat belts very often incorporate load-limiters as well as pretensioners. Published research has established that load-limiters and pretensioners increase the effectiveness of occupant protection systems. Some have argued that load-limiters with higher deployment thresholds are always better than load-limiters with lower deployment thresholds. Through testing, modeling and analysis, we have investigated this hypothesis, and in this paper we present test and modeling data as well as a discussion to this data and engineering mechanics to explain why this hypothesis is incorrect. Research presented in this paper shows that because load-limiters are just one component of a multi
Van Arsdell, William W., Weber, Paul, Stankewich, Charles, Larson, Brian, Hoover, Ryan, Watson, Richard
Optimization of Seatbelt Anchorage Mount Locations for Occupant Injury Reduction in Frontal Crash2016-28-025102/01/2016
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
Comparison of ATD to PMHS Response in the Under-Body Blast Environment2015-22-001711/09/2015
A blast buck (Accelerative Loading Fixture, or ALF) was developed for studying underbody blast events in a laboratory-like setting. It was designed to provide a high-magnitude, high-rate, vertical loading environment for cadaver and dummy testing. It consists of a platform with a reinforcing cage that supports adjustable-height rigid seats for two crew positions. The platform has a heavy frame with a deformable floor insert. Fourteen tests were conducted using fourteen PMHS (post mortem human surrogates) and the Hybrid III ATD (Anthropomorphic Test Device). Tests were conducted at two charge levels: enhanced and mild. The surrogates were tested with and without PPE (Personal Protective Equipment), and in two different postures: nominal (knee angle of 90°) and obtuse (knee angle of 120°). The ALF reproduces damage in the PMHS commensurate with injuries experienced in theater, with the most common damage being to the pelvis and ankle. Load is transmitted through the surrogates in a
Danelson, Kerry A., Kemper, Andrew R., Mason, Matthew J., Tegtmeyer, Michael, Swiatkowski, Sean A., Bolte IV, John H., Hardy, Warren N.
Finite Element Analysis and Validation of Bus Seat Structure as per AIS023: Safety Features Evaluation of Bus Seat using Hybrid III Dummy2015-01-286909/29/2015
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 Impact2015-36-026309/22/2015
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.
Improved Seat Belt Restraint Geometry for Frontal, Frontal Oblique and Rollover Incidents2015-01-074004/14/2015
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
Simulation Fidelity Improvement of H350 Lower Tibia Indices2015-01-057804/14/2015
Finite element dummy models have been more and more widely applied in virtual development of occupant protection systems across the automotive industry due to their predictive capabilities. H350 dyna dummy model [1] is a finite element representation of the Hybrid III male dummy [2], which is designed to represent the average of the United States adult male population. Lower extremity injuries continue to occur in front crash accidents despite increasing improvement of vehicle crashworthiness and occupant restraint system. It is therefore desirable to predict lower tibia injury numbers in front occupant simulations. Though lower tibia loading/index predictions are not studied as much as the FMVSS 208 regulated injury numbers, the tibia indices are injury criteria that need to be assessed during IIHS and Euro NCAP frontal offset occupant simulations. However during front crash simulations, it is very difficult to achieve good correlations or predictions of lower tibia loadings. A common
Li, Wei, Cheng, Yi-Pen, Furton, Lisa
The Application of Hybrid III 5 th Percentile Dummy FE Model for Rear Row Occupant Simulation in Frontal Crash Test2015-01-145804/14/2015
A Finite Element (FE) model for analysis of the rear row occupant injury assessment parameters in a frontal crash test was developed by using the LSTC Hybrid III 5th percentile FE dummy model. Three cases were studied using three different rear seatbelt retractor configurations, which were as follows: an ordinary retractor without load limiter or pretensioner (Case 1), a retractor with load limiter only (Case 2), and a retractor with load limiter and pretensioner (Case 3). The simulation results of each of these three cases were compared respectively to the results obtained from two frontal 50-kph full rigid barrier impact tests and one sled test. It turned out that the dummy kinematics and injury assessment parameters of the head, neck, chest, pelvis and femurs were all similar between test and simulation in the three cases. Thus, FE simulation models can be used to predict dummy injury assessment parameters. The chest and pelvis accelerations and chest deflection reduced, while the
Hu, Jia
Effects of Crash Pulse, Impact Angle, Occupant Size, Front Seat Location, and Restraint System on Rear Seat Occupant Protection2015-01-145304/14/2015
In this study, two sled series were conducted with a sled buck representing a compact vehicle. The first series of tests focused on the effects of crash pulse, impact angle, occupant size, and front seat location on rear seat occupant restraint with a generic rear-seat belt system without pre-tensioner or load limiter. The second series of tests focused on investigating the benefit of using advanced features for rear-seat occupant restraint in the most severe crash condition in the first sled series. The first series of tests include 16 test conditions with two impact angles (0° and 15°), two sled pulse (soft and severe), and four ATD sizes (HIII 6YO, HIII 5th female, HIII 95th male, and THOR-NT) with two ATDs in each test. The driver seat was located at the mid position, while the front passenger seat was positioned such that a constant distance between the ATD knee and the front seat is achieved. In all the tests, a generic rear-seat belt system without pre-tensioner, load limiter or
Hu, Jingwen, Fischer, Kurt, Lange, Paul, Adler, Angelo
Safety Belt Testing Apparatus2015-01-148504/14/2015
A new apparatus for testing modern safety belt systems was developed. The apparatus design, dynamic behavior and test procedure are described. A number of tests have been conducted using this apparatus. These tests allowed identification of key performance parameters of pretensioners and load limiting retractors which are relevant to occupant protection in a crash environment. Good test repeatability was observed, which allowed comparison of different safety belt designs. The apparatus may be used for better specification and verification of safety belt properties on a subsystem level as well as for the validation of CAE models of safety belts used in simulations of occupant response to crash events.
Kral, Jiri, Kondel, Theresa, Morra, Mark, Cassatta, Stephen, Bidolli, Peter, Stebbins, Patrick, Joshi, Vikas
Evaluation of Air Bag Electronic Sensing System Collision Performance through Laboratory Simulation2015-01-148404/14/2015
Since their inception, the design of airbag sensing systems has continued to evolve. The evolution of air bag sensing system design has been rapid. Electromechanical sensors used in earlier front air bag applications have been replaced by multi-point electronic sensors used to discriminate collision mechanics for potential air bag deployment in front, side and rollover accidents. In addition to multipoint electronic sensors, advanced air bag systems incorporate a variety of state sensors such as seat belt use status, seat track location, and occupant size classification that are taken into consideration by air bag system algorithms and occupant protection deployment strategies. Electronic sensing systems have allowed for the advent of event data recorders (EDRs), which over the past decade, have provided increasingly more information related to air bag deployment events in the field. To further aid in the evaluation of air bag field performance and interpretation of EDR downloads, a
Toomey, Daniel E., Winkel, Eric S., Krishnaswami, Ram
Sled Test Development and Occupant Protection Evaluation Based on the Frontal Crash Response of Heavy Trucks2014-01-242309/30/2014
Full-scale vehicle crash testing is an accurate method to reproduce many real-world crash conditions in a controlled laboratory environment. However, the costs involved in performing full-scale crash tests can be prohibitive for some purposes. Dynamic sled testing is a lower cost and widely used method to obtain multiple, useful data sets for development of frontal crash mitigating technologies, systems and components. Wherever possible, dynamic sled tests should use vehicle-specific deceleration pulses determined from full-scale vehicle crash tests. This paper establishes a dynamic sled test protocol based on data collected from eight full-scale heavy vehicle frontal crash tests. The sled test protocol is intended to be utilized as a basis for building a body of knowledge needed to update heavy vehicle frontal impact test recommended practices. These recommended practices provide direction for the development of frontal crash mitigating technologies, systems and components
Chinni, James, Hoover, Ryan
Implementation and importance of ISOFIX and Latch System in the Brazilian Automotive Market2014-36-016509/30/2014
The increase in crash tests done for independent entities of consumer protection, such as the Euro NCAP (Europe) or IIHS (United States) have shown increasingly importance for safety regarding the occupant protection. The consumer of the automotive market in developed countries, as United States or countries of European Union for example, they seek for a safer vehicle when buying a new one. On the other hand in Brazil, the consumer does not have the culture of buying a vehicle thinking in safety performance, but they choose the cars because of body style and accessories. The regulation of the Brazilian government's obligation to Air Bag and ABS brakes for all vehicles produced in the country from January 2014 and the INOVAR AUTO program, aims to bring more safety to vehicles produced in the country. And certainly the ISOFIX system will be one of the items that should be implemented in the coming years, because the government agency INMETRO, has made the rules for child seats with
Marcial, Mauro, Pereira, André Luiz, Jr, Eduardo Orfale, Freitas, Rodrigo Martins, Yamada, William
Uniform Provisions Concerning the Approval of: Vehicles with Regard to the Protection of the Occupants in the Event of a Frontal Collision.INT-REG-62207/04/2014
Occupant Protection in Frontal Collision.
A Methodology for Characterization of the Strain Rate-Dependent Behavior of PU Foam2014-01-053904/01/2014
Polymeric foams are known to be sensitive to strain rate under dynamic loads. Mechanical characterization of such materials would not thus be complete without capturing the effect of strain rate on their stress-strain behaviors. Consistent data on the dynamic behavior of foam is also necessary for designing energy-absorbing countermeasures based on foam such as for vehicle occupant safety protection. Strain rates of the order of 100-500 s−1 are quite common in such design applications; strain rates of this range cannot be obtained with an ordinary UTM (universal testing machine) and a special test set-up is usually needed. In the current study, a unique approach has been suggested according to which quasi-static tests at low strain rates and low velocity drop tests at medium strain rates are utilized to arrive at an empirical relation between initial peak stress and logarithm of strain rate for a rigid closed-cell PU foam. Using a stress-scaling methodology and the empirical relation
Shivakumar, N., Deb, Anindya, Chou, Clifford, Chittappa, H.
Uniform Provisions Concerning the Approval of: Vehicles with Regard to the Protection of the Occupants in the Event of a Frontal Collision.INT-REG-56902/28/2014
Occupant Protection in Frontal Collision.
Uniform Provisions Concerning the Approval of: Vehicles with Regard to the Protection of the Occupants in the Event of a Frontal Collision.INT-REG-52710/10/2013
Occupant Protection in Frontal Collision.
Vehicle Restraint System Optimization for Frontal Impact2013-36-047310/07/2013
The Brazilian Automotive regulations that are aimed towards the safety of drivers, passengers and pedestrians have gone through recent changes to prevent and/or minimize injury and trauma from different types of accidents. Until now, National Traffic Council (CONTRAN) Resolution n° 14/98 required vehicles to only have safety belts for an occupant restraint system, and frontal airbags were not required. Since the recent CONTRAN n° 311/09 Resolution requires mandatory frontal airbags, the occupant restraint system must be tuned due to the interaction with different components that may make up the system, like safety belts with pretensioners and seatbelt load limiting devices. The present study was developed to optimize the restraint system of a current vehicle in production, while focusing on minimizing the vehicle complexity. The optimization tool helped to develop a robust restraint system for the frontal passenger during a frontal impact [1]. The numerical computational model created
Rosa, Mateus A. Santa, Callaghan, Brian, Guido, Carlos A. Prado, de Lima, Anderson
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