Browse Topic: Frontal collisions

Items (793)
ABSTRACT Seatbelt-mounted airbag is a new type of occupant restraint system, in which the airbag is integrated into the seatbelt and hence can be easily and quickly implemented into the current tactical vehicles without significant vehicle structure or interior changes. The objective of this study was to develop, optimize, and demonstrate seatbelt-mounted airbag designs for reducing occupant injury risks in a light tactical vehicle under frontal crashes. A total of 19 sled tests and over 30 FE simulations were performed to find the optimal seatbelt-mounted airbag designs for protecting occupants represented by three sizes of ATDs and two military gear configurations. Various lap-belt-mounted airbag and shoulder-belt-mounted airbag designs were evaluated for driver, front-seat passenger, and rear-seat passenger locations in a tactical vehicle. The test and simulation results showed that the optimized designs substantially reduced the occupant injury risks to the head, neck, and chest
Hu, JingwenOrton, NicholeBoyle, KyleAshok, NikhilKlima, JulieStaniak, CeliaScherer, RisaReed, Matthew
ABSTRACT The work presented here comprises preliminary results for calibrating the IMPETUS Afea Hybrid III 50th percentile Male ATD for a blast scenario. The calibration of the ATD model based upon the requirements defined for frontal crash impact are presented followed by a discussion of the blast survivability tests that were performed at General Dynamics Edgefield Test Center in South Carolina. The model setup for the calibration based upon the blast tests are presented which includes a discussion of the seating and blast models. Preliminary numerical results for Lumbar and Lower Tibia forces are compared with the experimental results. The correlation was good and calibration of the remaining critical parameters continues
Jensen, Morten RikardHonaker, MikeBoglaev, Alex
ABSTRACT The objective of this study was to optimize the occupant restraint systems (including both seatbelt and airbag) in a light tactical vehicle under frontal crash conditions through a combination of sled testing and computational modeling. Two iterations of computational modeling and sled testing were performed to find the optimal restraint design solutions for protecting occupants represented by three size of ATDs (namely Hybrid-III 5th percentile female ATD, 50th percentile male ATD, and 95th male ATD) and two military gear configurations, namely improved outer tactical vest (IOTV) and SAW Gunner configuration using a tactical assault panel (TAP). The sled tests with the optimized seatbelt and airbag designs provided significant improvement on the head, neck, chest, and femur injury risks compared to the baseline tests. This study demonstrated the benefit of adding a properly designed airbag and advanced seatbelt to improve the occupant protection in frontal crashes for a light
Hu, JingwenOrton, NicholeChen, CongRupp, Jonathan D.Reed, Matthew P.Gruber, RebekahScherer, Risa
ABSTRACT The objective of this study is to understand the occupant kinematics and injury risks in a light tactical vehicle under frontal crash conditions using a combination of physical tests and computer simulations. A total of 20 sled tests were conducted in a representative environment to understand occupant kinematics, and quantify the effects from occupant body size (5th/50th/95th), military gear (helmet/vest/varying gear configurations), seatbelt type (5point/3point), and advanced seatbelt features (pre-tensioner/load limiter) on occupant kinematics and injury risks in frontal crashes. These tests have been used to validate a set of finite element (FE) models of occupants, gear, and restraints. Kinematics exhibited often included submarining due to the lack of knee bolster and the added weight from the military gear. Body size, seatbelt type, and advanced belt features also showed significant effects on occupant kinematics
Hu, JingwenWood, LaurenOrton, NicholeChen, CongRupp, JonathanReed, MatthewGruber, RebekahScherer, Risa
Prevention and diagnosis of traumatic brain injuries (TBI) are reliant on understanding the biomechanical response of the brain to external stimuli. Finite element models (FEM) and artificial head surrogates are becoming a common method of investigating the dynamic response of the brain to injurious impact and inertial stimuli. The accuracy and validity of these models is reliant on postmortem human subject (PMHS) research to produce biofidelic brain tissue responses. Previous PMHS research has been performed to measure intracranial pressures, displacements, and strains when subjected to impact and inertial loading; however, there remains a need for additional PMHS datasets to improve our understanding of the brain’s dynamics. The purpose of this study is to measure the relative brain–skull displacement in a PMHS specimen when subjected to blunt force impacts. A high-speed X-ray (HSXR) imaging system and embedded radiopaque elastomeric markers were used to record PMHS impacts at
Demiannay, Jean-JacquesRovt, JenniferBrannen, MacKenzieXu, ShengKang, GiaYip, AshleyAzadi, Amir HosseinDehghan, ParisaGoodwin, ShannonTaylor, ReggiePoon, KatherineBrien, SusanHoshizaki, BlaineKarton, ClaraPetel , Oren
Seventeen research posters were prepared and presented by student authors. The posters covered a wide breadth of works-in-progress and recently completed projects. Topics included a variety of body regions and injury scenarios: Biofidelity Corridors of Powered Two-Wheeler Rider Kinematics from Full-Scale Crash Testing Using Postmortem Human Subjects, Meringolo et al. Cervical Vertebral and Spinal Cord Injuries Remain Overrepresented in Rollover Occupants, Al-Salehi et al. The Effect of Surfaces on Knee Biomechanics during a 90-Degree Cut, Rhodes et al. Investigating the Variabilities in the Spinal Cord Injury in Pig Models Using Benchtop Test Model and Ultrasound Analyses, Borjali et al. Relationship between Tackle Form and Head Kinematics in Youth Football, Holcomb et al. Comparing Motor Vehicle Collision Injury Incidence between Pregnant and Nonpregnant Individuals: A Case–Control Study, Levine et al. Development of an Automated Pipeline to Characterize Full Rib Cage Shape
Bautsch, Brian T.Cripton, Peter A.Cronin, Duane
Forward-facing child restraint systems (FF CRS) and high-back boosters often contact the vehicle seat head restraint (HR) when installed, creating a gap between the back surface of the CRS and the vehicle seat. The effects of HR interference on dynamic CRS performance are not well documented. The objective of this study is to quantify the effects of HR interference for FF CRS and high-back boosters in frontal and far-side impacts. Production vehicle seats with prominent, removeable HRs were attached to a sled buck. One FF CRS and two booster models were tested with the HR in place (causing interference) and with the HR removed (no interference). A variety of installation methods were examined for the FF CRS. A total of twenty-four tests were run. In frontal impacts, HR interference produced small but consistent increases in frontal head excursion and HIC36. Head excursions were more directly related to the more forward initial position rather than kinematic differences caused by HR
Mansfield, Julie A.
With the current trend of including the evaluation of the risk of brain injuries in vehicle crashes due to rotational kinematics of the head, two injury criteria have been introduced since 2013 – BrIC and DAMAGE. BrIC was developed by NHTSA in 2013 and was suggested for inclusion in the US NCAP for frontal and side crashes. DAMAGE has been developed by UVa under the sponsorship of JAMA and JARI and has been accepted tentatively by the EuroNCAP. Although BrIC in US crash testing is known and reported, DAMAGE in tests of the US fleet is relatively unknown. The current paper will report on DAMAGE in NCAP-like tests and potential future frontal crash tests involving substantial rotation about the three axes of occupant heads. Distribution of DAMAGE of three-point belted occupants without airbags will also be discussed. Prediction of brain injury risks from the tests have been compared to the risks in the real world. Although DAMAGE correlates well with MPS in the human brain model across
Prasad, PriyaBarbat, Saeed D.Kalra, AnilDalmotas, Dainius J.
There are established federal requirements and industry standards for frontal crash testing of motor vehicles. Consistently applied methods support reliability, repeatability, and comparability of performance metrics between tests and platforms. However, real world collisions are rarely identical to standard test protocols. This study examined the effects of occupant anthropometry and passive restraint deployment timing on occupant kinematics and biomechanical loading in a moderate-severity (approximately 30 kph delta-V) offset frontal crash scenario. An offset, front-to-rear vehicle-to-vehicle crash test was performed, and the dynamics of the vehicle experiencing the frontal collision were replicated in a series of three sled tests. Crash test and sled test vehicle kinematics were comparable. A standard or reduced-weight 50th percentile male Hybrid III ATD (H3-50M) or a standard 5th percentile female Hybrid III ATD (H3-5F) was belted in the driver’s seating position. In the crash test
Courtney, AmyCrosby, CharlesMiller, BruceOsterhout, AaronWalker, JamesGondek, Jonathon
This study was conducted to assess the occupant restraint use and injury risks by seating position. The results were used to discuss the merit of selected warning systems. The 1989-2015 NASS-CDS and 2017-2021 CISS data were analyzed for light vehicles in all, frontal and rear tow-away crashes. The differences in serious injury risk (MAIS 3+F) were determined for front and rear seating positions, including the right, middle and left second-row seats. Occupancy and restraint use were determined by model year groups. Occupancy relative to the driver was 27% in the right-front (RF) and 17% in the second row in all crashes. About 39% of second-row passengers were in the left seat, 15% in the center seat and 47% in the right seat. Restraint use was lower in the second row compared to front seats. It was 43% in the right-front and 32% in the second-row seats in all crashes involving serious injury. Restraint use increased with model year groups. It was 63% in the ‘61-‘89 MY vehicles and 90
Parenteau, ChantalBurnett, Roger
There is little prior research into chain-collisions, despite their relatively large contribution to injury and harm in motor-vehicle collisions. This study conducted a series of rear-impact, front-impact, and chain-collision impacts using a bumper car ride at an active amusement park as a proxy for automobiles. The purpose was to begin to identify the threshold time range when separate, discrete collisions transition into a hybrid or combined chain-collision mode and provide bases for future analyses. The test series consisted of rear impacts into an occupied target vehicle from a driven bullet vehicle; frontal impacts into a perimeter barrier (wall); chain-collisions consisting of a driven bullet vehicle striking an occupied primary target vehicle, which then collided with a non-occupied secondary target vehicle; and chain-collisions consisting of a driven bullet vehicle striking an occupied primary target vehicle which then collided with a wall. Time between collisions was adjusted
Bussone, William R.Koiler, RezaBenda, JamieCarney, NicholasGeffard, AndresSam, Samantha
For the design optimization of the electric bus body frame orienting frontal crash, considering the uncertainties that may affect the crashworthiness performance, a robust optimization scheme considering tolerance design is proposed, which maps the acceptable variations in objectives and feasibility into the parameter space, allowing for the analysis of robustness. Two contribution analysis methods, namely the entropy weight and TOPSIS method, along with the grey correlation calculations method, are adopted to screen all the design variables. Fifteen shape design variables with a relatively high impact are chosen for design optimization. A symmetric tolerance and interval model is used to depict the uncertainty associated with the 15 shape design variables of key components in the bus body frame to form an uncertainty optimization problem in the form of an interval, and a triple-objective robust optimization model is developed to optimize the shape design variables and tolerances
Yang, XiujianLiu, Beizhen
Lane changing is an essential action in commercial vehicles to prevent collisions. However, steering system malfunctions significantly escalate the risk of head-on collisions. With the advancement of intelligent chassis control technologies, some autonomous commercial vehicles are now equipped with a four-wheel independent braking system. This article develops a lane-changing control strategy during steering failures using torque vectoring through brake allocation. The boundaries of lane-changing capabilities under different speeds via brake allocation are also investigated, offering valuable insights for driving safety during emergency evasions when the steering system fails. Firstly, a dual-track vehicle dynamics model is established, considering the non-linearity of the tires. A quintic polynomial approach is employed for lane-changing trajectory planning. Secondly, a hierarchical controller is designed. The upper layer employs a three-stage cascaded proportional integral controller
Lu, AoLi, RunfengYinggang, XuNie, ZexinLi, PeilinTian, Guangyu
Due to the lack of biofidelity seen in GHBMC M50-O in rear-facing impact simulations involving interaction with the seat back in an OEM seat, it is important to explore how the boundary conditions might be affecting the biofidelity and potentially formulate methods to improve biofidelity of different occupant models in the future while also maintaining seat validity. This study investigated the influence of one such boundary condition, which is the seat back foam material properties, on the thorax and pelvis kinematics and injury outcomes of the GHBMC 50th M50-O model in a high-speed rear-facing frontal impact scenario, which involves severe occupant loading of the seat back. Two different seat back foam materials were used – a stiff foam with high densification and a soft foam with low densification. The peak magnitudes of the T-spine resultant accelerations of the GHBMC M50-O increased with the use of soft foam as compared to stiff foam. However, the change in the average biofidelity
Pradhan, VikramRamachandra, RakshitKang, Yun Seok
In day-to-day life, accidents do occur frequently all around the globe. It is difficult to prevent these accidents as they occur due to different reasons, which cannot be easily controlled. However, the fatal injuries occurring to passengers can be reduced by installing efficient safety systems in vehicles, which will help in saving the lives of mankind. Many safety systems are being installed in vehicles such as seat belt restraints, airbags, 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's body during vehicle crashes, which can lead to fatal injuries and sometimes even death during vehicle crashes. 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 crashes on flat rigid
Vinodh, T.Dineshkumar, C.Jeyakumar, P.D.Muthiya, Solomon JenorisVinayagam, Nadana KumarChristu Paul, R.Dhanraj, Joshuva Arockia
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 was 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
Pre-crash vehicle maneuvers are known to affect occupant posture and kinematics, which consequently may influence injury risks during a collision. In this study, the influence of pre-crash vehicle maneuvers on the injury risks of front-seated occupants during a frontal crash was numerically evaluated. A generic buck vehicle model was developed based on a publicly available FE model, which included the vehicle interior and the front passenger airbag (PAB). The pre-crash phase was simulated using specific rigid-body human models with active joints (GHBMCsi-pre models) developed based on exterior shapes of the simplified deformable human model (GHBMCsi) representing a 50th male subject. Two pre-crash maneuvers representing (1) a generic 1g braking and (2) turning-and-braking scenarios were simulated. Then, the kinematics data of belted GHBMCsi-pre models were transferred using a developed switch algorithm to the corresponding GHBMCsi models, which can predict occupant injury risks
Dahiya, AkshayUntaroiu, Costin
Letter from the Special Issue Editors
Mueller, BeckyBautsch, BrianMansfield, Julie
Objective: This study aimed to optimize restraint systems and improve safety equity by using parametric human body models (HBMs) and vehicle models accounting for variations in occupant size and shape as well as vehicle type. Methodology: A diverse set of finite element (FE) HBMs were developed by morphing the GHBMC midsize male simplified model into statistically predicted skeleton and body shape geometries with varied age, stature, and body mass index (BMI). A parametric vehicle model was equipped with driver, front passenger, knee, and curtain airbags along with seat belts with pretensioner(s) and load limiter and has been validated against US-NCAP results from four vehicles (Corolla, Accord, RAV4, F150). Ten student groups were formed for this study, and each group picked a vehicle model, occupant side (driver vs. passenger), and an occupant model among the 60 HBMs. About 200 frontal crash simulations were performed with 10 combinations of vehicles (n = 4) and occupants (m = 8
Yang, ZhenhaoDesai, AmoghsiddBoyle, KyleRupp, JonathanReed, MatthewHu, Jingwen
Field data has shown that belt-positioning boosters help reduce the risk of injury to children in a crash. This study builds on prior submarining work (Slusher et al. 2022) and aims to analyze kinetic metrics (which can be easily recorded from anthropomorphic test devices in crash tests) in submarining and non-submarining conditions for a 6-year-old pediatric human occupant in frontal crashes
Williams, BethanyMaheshwari, Jalaj
Bilateral knee impacts were conducted on Hybrid III and THOR 5th percentile female anthropomorphic test devices (ATDs), and the results were compared to previously reported female PMHS data. Each ATD was impacted at velocities of 2.5, 3.5, and 4.9 m/s. Knee–thigh–hip (KTH) loading data, obtained either via direct measurement or through exercising a one-dimensional lumped parameter model (LPM), was analyzed for differences in loading characteristics including the maximum force, time to maximum force, loading rate, and loading duration. In general, the Hybrid III had the highest loading rate and maximum force, and the lowest loading duration and time to peak force for each point along KTH. Conversely, the PMHS generally had the lowest loading rate and maximum force, and the highest loading duration and time to peak force for each point along KTH. The force transfer from the knee to the femur was 79.2 ± 0.3% for the Hybrid III 5th female, 82.7 ± 0.4% for the THOR-05F, and 70.6 ± 1.7% for
Carpenter, Randolff L.Berthelson, Parker R.Donlon, John-PaulForman, Jason L.
Rib fractures are associated with high rates of morbidity and mortality. Improved methods to assess rib bone quality are needed to identify at-risk populations. Quantitative computed tomography (QCT) can be used to calculate volumetric bone mineral density (vBMD) and bone mineral content (BMC), which may be related to rib fracture risk. The objective of this study was to determine if vBMD and BMC from QCT predict human rib structural properties. 127 mid-level (5th–7th) ribs were obtained from adult female (n = 67) and male (n = 60) postmortem human subjects (PMHS). Isolated rib QCT scans were performed to calculate vBMD and BMC. Each rib was subsequently tested to failure in a dynamic simulated frontal impact and structural properties, peak force (FPeak), percent displacement (δPeak), linear structural stiffness (K), and total energy (UTot) were calculated. vBMD demonstrated no significant differences between sexes (p > 0.05); however, males had a higher BMC than females (p < 0.001
Haverfield, Z.A.Hunter, R.L.Kang, Y.S.Patel, A.B.Agnew, A.M.
The objective of this study was to compare head, neck, and chest injury risks between front and rear-seated Hybrid III 50th-percentile male anthropomorphic test devices (ATDs) during matched frontal impacts. Seven vehicles were converted to rear seat test bucks (two sedans, three mid-size SUVs, one subcompact SUV, and one minivan) and then used to perform sled testing with vehicle-specific frontal NCAP acceleration pulses and a rear seated (i.e., second row) Hybrid III 50th male ATD. Matched front seat Hybrid III 50th male ATD data were obtained from the NHTSA Vehicle Crash Test Database for each vehicle. HIC15, Nij, maximum chest acceleration, and maximum chest deflection were compared between the front and rear seat tests, as well as between vehicles with conventional and advanced three-point belt restraint systems in the rear seat. Additionally, a modified version of the NCAP frontal star rating was calculated for the front and rear seat tests. All injury metrics, except for chest
Bianco, Samuel T.Albert, Devon L.Guettler, Allison J.Hardy, Warren N.Kemper, Andrew R.
Previous volunteer studies focused on low-speed frontal events have demonstrated that muscle activation (specifically pre-impact bracing) can significantly affect occupant response. However, these tests do not always include a sufficient number of small female volunteers to compare their unique responses to the typically studied midsize male population. The purposes of this study were to quantify the occupant kinetics and muscle responses of relaxed and braced small female and midsize male volunteers during low-speed frontal sled tests and to compare between muscle states and demographic groups. Small female and midsize male volunteers experienced multiple low-speed frontal sled tests consisting of two pulse severities (1 g and 2.5 g) and two muscle states (relaxed and braced) per pulse severity. The muscle activity of 30 muscles (15 bilaterally) and reaction forces at the volunteer-test buck interfaces and seat belt were measured before and during each sled test. Compared to the
Chan, HanaAlbert, Devon L.Gayzik, F. ScottKemper, Andrew R.
This study compares statistical models for frontal crash injuries based on delta-v data reported by the vehicle event data recorder (EDR) with injury probability models based on delta-v reconstructed by Crash Investigation Sampling System (CISS) investigators. Injury probabilities and their follow-on use in advanced automatic crash notification (AACN) systems have traditionally been based on delta-v obtained through accident reconstruction of field crashes in the National Automotive Sampling System Crash Data System (NASS-CDS) database. Field delta-v from EDRs in the CISS database is an alternative source of information for crash injury probability modeling. In this study, frontal impact injury risk probabilities computed from EDR and reconstructed delta-v were compared. All data came from the years 2017–2021 of the CISS database, which contains EDR downloads and also reconstructed delta-v using crush measurements and NHTSA’s WinSmash software. On average, CISS reconstructions
Watson, Richard A.Bonugli, EnriqueGreenston, Mathew
The reality of the autonomous vehicle in a near future is growing and is expected to induce significant change in the occupant posture with respect to a standard driving posture. The delegated driving would allow sleeping and/or resting in a seat with a reclined posture. However, the data in the literature are rare on the body kinematics, human tolerance, and injury types in such reclined postures. The current study aims at increasing the knowledge in the domain and providing useful data to assess the relevance of the standard injury assessment tools such as anthropomorphic test devices or finite element human body models. For that purpose, a test series of three male Post-Mortem Human Subjects (PMHS) were performed in frontal impact at a 13.4 m/s delta V. The backseat inclination was 58 degrees with respect to the vertical axis. The semi-rigid seat developed by Uriot et al. (2015) was used with a stiffer seat ramp. The restraint was composed of a lap belt equipped with two 3.5 kN load
Baudrit, PascalUriot, JérômeRichard, OlivierDebray, Matthieu
The American population is getting heavier and automated vehicles will accommodate unconventional postures. While studies replicating mid-size and upright fore-aft seated occupants are numerous, experiments with post-mortem human subjects (PMHS) with obese and reclined occupants are sparse. The objective of this study was to compare the kinematics of the head-neck, torso and pelvis, and document injuries and injury patterns in frontal impacts. Six PMHS with a mean body mass index of 38.2 ± 5.3 kg/m2 were equally divided between upright and reclined groups (seatback: 23°, 45°), restrained by a three-point integrated belt, positioned on a semi-rigid seat, and exposed to low and moderate velocities (15, 32 km/h). Data included belt loads, spinal accelerations, kinematics, and injuries from x-rays, computed tomography, and necropsy. At 15 km/h speed, no significant difference in the occupant kinematics and evidence of orthopedic failure was observed. At 32 km/h speed, the primary
Somasundaram, KarthikHumm, John R.Yoganandan, NarayanHauschild, HansDriesslein, KlausPintar, Frank A.
In order to evaluate the THOR-50M as a front impact Anthropomorphic Test Device (ATD) for vehicle safety design, the ATD was compared to the H3-50M in matching vehicle crash tests for 20 unique vehicle models from 2 vehicle manufacturers. For the belted driver condition, a total of fifty-four crash tests were investigated in the 56.3 km/h (35 mph) front rigid barrier impact condition. Four more tests were compared for the unbelted driver and right front passenger at 40.2 km/h (25 mph) in the flat frontal and 30-degree right oblique rigid barrier impact conditions. The two ATDs were also evaluated for their ability to predict injury risk by comparing their fleet average injury risk to Crash Investigation Sampling System (CISS) accident data for similar conditions. The differences in seating position and their effect on ATD responses were also investigated. This study showed that the belted THOR-50M injury responses were higher than the H3-50M by 25%-180%, in all reported ATD responses
O’Connor, ChrisKim, AgnesBarrette, TimDix, Jeff
TOC
Tobolski, Sue
Frontal crashes are the most common crash mode in the US vehicle fleet, and a large proportion of these crashes are “fender-benders” or low-speed collisions. This, among other considerations, led the Insurance Institute for Highway Safety (IIHS) to conduct a series of low-speed front and rear bumper impact tests. These crash tests have been performed on passenger vehicles manufactured by various manufacturers since 1970 and continuing through the 2009 model year. Test data and video for individual tests are available through IIHS’s online data portal, most extensively for model years 2007 to 2009. While IIHS’s test protocol varied over the years, these tests specified, in part, a full engagement impact of the tested vehicle into a rigid, bumper-shaped barrier covered with an energy absorber. Although IIHS reported the closing speed for each test, they did not report the separation speed or crash pulse duration. These values have been determined, in the current study, by analyzing the
Paradiso, MarcMcDowell, Eric
Airbag and seat belt pretensioner deployment characteristics depend on multiple factors, such as the magnitude, direction, and rate of vehicle deceleration as detected by vehicle crash sensors and evaluated by vehicle-specific algorithms. Frontal airbag and pretensioner deployments are likely to be commanded during frontal crash events with high initial vehicle deceleration typically associated with high vehicle change in velocity (delta-V). However, within a range of moderate changes in vehicle speeds, referred to as the “gray zone,” a vehicle-specific algorithm may or may not command deployment depending on crash pulse parameters and occupant sensing, among other items. Publicly available testing in the moderate-speed range is lacking and would be useful to evaluate the effects of airbag and pretensioner deployment on occupant kinematics and loading. In this study, sled tests were performed using a standard passenger vehicle buck simulating frontal deceleration impact events in a
Sharpe, Sarah S.Grijalva, SandraAllin, LeighCourtney, AmyToney-Bolger, MeganPokutta-Paskaleva, AnastassiaCrosby, Charles L.Carhart, Michael
This SAE Recommended Practice describes common definitions and operational elements of Event Data Recorders. The SAE J1698 series of documents consists of the following: SAE J1698-1 - Event Data Recorder - Output Data Definition: Provides common data output formats and definitions for a variety of data elements that may be useful for analyzing vehicle crash and crash-like events that meet specified trigger criteria. SAE J1698-2 - Event Data Recorder - Retrieval Tool Protocol: Utilizes existing industry standards to identify a common physical interface and define the protocols necessary to retrieve records stored by light duty vehicle Event Data Recorders (EDRs). SAE J1698-3 - Event Data Recorder - Compliance Assessment: Defines procedures that may be used to validate that relevant EDR output records conform with the reporting requirements specified in Part 563, Table 1 during the course of FMVSS-208, FMVSS-214, and other applicable vehicle level crash testing
Event Data Recorder Committee
Human thoracic injury under frontal collisions is an inevitable problem in vehicle safety research. Compared with the Multiple Rigid-Body Models (MRBMs) and Finite Element Human Body Models (FEHBMs), Mathematical Equivalent Models (MEMs) can not only provide important data but also improve the research efficiency. The current thoracic MEMs usually adapted the mechanical isolation method to isolate the thorax from the human body; therefore, the effects of the head, neck, and lower body internal organs on the mechanical responses of the thorax are not considered. In this article, a new thoracic MEM, named as Improved Consistent Lobdell Model (ICLM), is developed based on the concentrated mass-spring-damping system to consider the energy absorbed by the deformation of the internal soft tissue and the motion hysteresis of the head, neck, and lower body. Thorax equivalent stiffness curve predicted by the ICLM has a good fit with the corridor obtained by the Post-Mortem Human Subjects (PMHS
Liu, ZhixinZheng, HongMa, Weijie
Though there are active safety features in the passenger cars, unfortunately not all accidents are avoidable. Airbags are the passive safety feature which avoid occupants in colliding with the car interiors and help to mitigate the fatal injuries. Trend and interest in the recent times is to study the occupant injury for front row seats. The second-row occupants are usually protected with the passive safety systems by Seat belts, Inflatable Curtain airbags, seat airbags, Windshield airbags etc. These are installed in the side and rear areas of car to pass on the regulations like FMVSS, ECE and other global standards. This particular case study is to evaluate or say how effective are the occupants in the second rows if they are unbelted. In few of the crash tests and experiment of frontal impact collision, the child dummies will be placed on female dummy lap without wearing the seat belt. In this, we see the second-row occupants will be seriously injured in most of the cases. Though the
Srinivasa, PraveenSundaram, BalachandarPatil, Shubham
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
This SAE Recommended Practice describes the dynamic testing procedures required to evaluate the integrity of patient compartment interior Storage Compartments such as cabinets, drawers, or refillable supply pouch systems when exposed to a frontal, side or rear impact (i.e., a crash impact). Its purpose is to provide component manufacturers, ambulance builders, and end-users with testing procedures and, where appropriate, acceptance criteria that, to a great extent, ensure interior Storage Compartments or systems meet the same performance criteria across the industry. Descriptions of the test set-up, test instrumentation, photographic/video coverage, test fixture, and performance metrics are included
Truck Crashworthiness Committee
This SAE Recommended Practice describes the dynamic and static testing procedures required to evaluate the integrity of the ambulance substructure, to support the safe mounting of an SAE J3027 compliant litter retention device or system, when exposed to a frontal, side or rear impact (i.e., a crash impact). Its purpose is to provide manufacturers, ambulance builders, and end-users with testing procedures and, where appropriate, acceptance criteria that to a great extent ensure the ambulance substructure meets the same performance criteria across the industry. Prospective manufacturers or vendors have the option of performing either dynamic testing or static testing. Descriptions of the test set-up, test instrumentation, photographic/video coverage, test fixture, and performance metrics are included
Truck Crashworthiness Committee
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
This procedure establishes a recommended practice for performing a Low Speed Thorax Impact Test to the Hybrid III Small Female Anthropomorphic Test Device (ATD or crash dummy). This test was created to satisfy the demand by the industry to have a certification test which results in peak chest deflection similar to current full vehicle, frontal impact tests. An inherent problem exists with the current certification procedure because the normal (6.7 m/s) thorax impact test has test results for peak chest deflection that are greater than those currently seen in full vehicle, frontal tests. The intent of this document is to develop a low speed thorax certification procedure for the H-III5F dummy with a 3.0 m/s impact similar to the SAE J2779 procedure for the H-III50M dummy
Dummy Testing and Equipment Committee
The Test Device for Human Occupant Restraint (THOR) is an advanced crash test dummy designed for frontal impact. Originally released in a 50th percentile male version (THOR-50M), a female 5th version (THOR-05F) was prototyped in 2017 (Wang et al., 2017) and compared with biofidelity sub-system tests (Wang et al., 2018). The same year, Trosseille et al. (2018) published response corridors using nine 5th percentile female Post Mortem Human Subjects (PMHS) tested in three sled configurations, including both submarining and non-submarining cases. The goal of this paper is to provide an initial evaluation of the THOR-05F biofidelity in a full-scale sled test, by comparing its response with the PMHS corridors published by Trosseille et al. (2018). Significant similarities between PMHS and THOR-05F were observed: as in Trosseille et al. (2018), the THOR-05F did not submarine in configuration 1, and submarined in configurations 2 and 3. The lap belt tension and seat forces were similar in
Richard, OlivierLebarbé, MatthieuUriot, JérômeTrosseille, XavierPetit, PhilippeWang, Z. JerryLee, Ellen
Vehicles with automated driving systems (ADS) may allow nontraditional seating arrangements, such as a reclined seat that is rear facing in a frontal impact. Currently, there is not a widely accepted, commercially available, anthropomorphic test device (ATD) that is designed for a reclined, rear-facing, high-speed crash situation. To begin to identify what modifications are needed for candidate ATDs to exhibit human-like characteristics in these nontraditional scenarios, ATDs should be tested and compared to available postmortem human subject (PMHS) biofidelity response corridors in these seating arrangements. The first objective of this study was to present and discuss updates to the Biofidelity Ranking System (BRS). The second objective was to use the updated BRS to evaluate the responses of the THOR 50th percentile male (Test device for Human Occupant Response, THOR-50M) ATD in the rear-facing condition. Quantitative comparisons were made between the THOR responses and biofidelity
Hagedorn, AlenaStammen, JasonRamachandra, RakshitRhule, HeatherThomas, ColtonSuntay, BrianKang, Yun-SeokKwon, Hyun JungMoorhouse, KevinBolte IV, John H.
The first objective of this study, addressed in Part 1, is to use finite element (FE) human body modeling (HBM) to evaluate the tangent of the Belt-to-Pelvis angle (tanθBTP) as a submarining predictor in frontal crashes for occupants in reclined seats. The second objective, addressed in Part 2, is to use this predictor to assess two technical solutions for reducing submarining risks for two different occupant anthropometries. In Part 1, tanθBTP (the lap belt penetration from the anterior superior iliac spine [ASIS] in the abdominal direction) was evaluated in impact simulations with varying seat belt anchor positions. Sled simulations with a 56 km/h full-frontal crash pulse were performed with the SAFER HBM morphed to the anthropometry of a small female and average male. A correlation was found between the submarining predictor and submarining. In Part 2, the anti-submarining solutions (i) split buckle belt system and (ii) anchor moving system were evaluated using the submarining
Saito, HiroyukiPipkorn, BengtLubbe, Nils
While historically the rear seat has been considered safer than the front seat, recent studies have suggested that adult occupants have a higher relative risk of injury and death in the rear seat compared to the front seat. Advancements in safety technologies in the front seat have outpaced those in the rear seat, where they vary greatly between vehicle makes and models. Of particular concern is occupant submarining, for which the lap belt slips off of the pelvis and directly loads the abdomen. In this study, frontal crash sled tests with seven vehicle bucks were conducted to assess submarining protection for two rear-seated 50th-percentile male anthropomorphic test devices (ATDs), the Hybrid III-50M and THOR-50M. Tests involved either a ΔV of 56 kph or 32 kph. Submarining incidence and severity for the Hybrid III and THOR were assessed using post-test photographs, high-speed videos, and seat belt loads. Abdominal pressure (using the ABdominal Injury and SUbmarining Prediction [ABISUP
Guettler, Allison JeanBianco, Samuel T.Kemper, Andrew R.Albert, Devon L.Hardy, Warren N.
The objective of this study was to evaluate the thoracic response and injury metrics of the Hybrid III (HIII-50M) and Test device for Human Occupant Restraint (THOR-50M) 50th-percentile male Anthropomorphic Test Devices (ATDs) during frontal, rear-seated sled tests using modern vehicles with various rear seat characteristics. Test bucks were fabricated from seven vehicles (two sedans, three midsize sport utility vehicles [SUVs], one SUV, and one minivan) that represented varying levels of rear seat designs and safety technologies, e.g., three vehicles had advanced restraints with pretensioners (PT) and load limiters (LL). Twenty-four frontal sled tests were conducted using three sled pulses derived from the vehicle-specific New Car Assessment Program (NCAP) crash pulses (NCAP85 ΔV = 56 kph, Scaled ΔV = 32 kph, and Generic ΔV = 32 kph). The HIII-50M and THOR-50M ATDs were positioned in the right and left rear seats, respectively. Maximum chest acceleration (3 ms clip), maximum chest
Bianco, SamuelGuettler, Allison J.Hardy, Warren N.Albert, Devon L.Kemper, Andrew R.
The preeminent obligation of the automotive engineers, while designing a car, is to assure the driver’s well-being during any kind of impact by suppressing intrusions into the cockpit or minacious deceleration levels. Technologists and designers are advancing various modern active and passive safety systems to augment vehicle occupants’ safety. To mitigate the research and development expenditure in time and money, it is recommended to utilize computational crash simulations for the early evaluation of safety behavior under vehicle impact tests. Therefore, in this research study, an attempt is made to simulate crashworthiness and design the impact attenuator utilized in Formula SAE (FSAE) vehicles to absorb the kinetic energy of a car during a frontal collision. Closed-cell aluminum foam is selected as its material because of its less density than solid metals and ability to undergo large deformations at almost constant load. CAE software is used to carry out explicit dynamic impact
Arora, PiyushVenkatachalam, Gopalan
One potential nonstandard seating configuration for vehicles with automated driving systems (ADS) is a reclined seat that is rear facing in a frontal collision. However, there are very limited biomechanical data in the rear-facing seating configuration in high-speed frontal collisions. The objectives of this study are (1) To investigate biomechanical responses and injuries from postmortem human subjects (PMHS) seated in an original equipment manufacturer (OEM) seat with a fixed D-ring (FDR) in a rear-facing frontal impact with ΔV of 56 km/h and (2) To compare PMHS responses and injuries from the FDR condition to those from an all-belts-to-seat (ABTS) condition tested in a previous study. The seat was rigidized in the rearward direction using a reinforcing frame that contained instrumentation to measure occupant loads applied to the seats. PMHS kinematics were measured using accelerometers and angular rate sensors that were installed at various body regions. Strain gages were attached
Kang, Yun-SeokStammen, JasonBendig, AlexanderAgnew, AmandaHagedorn, AlenaThomas, ColtonRamachandra, RakshitKwon, Hyun JungMoorhouse, KevinBolte, John
Frontal collision is the leading cause of passenger vehicle occupant death in the recent years. Active safety systems like automatic emergency braking has been demonstrated to be able to mitigate frontal collision or to reduce collision impact. However, braking is not as effective as steering when host vehicle is at high speed, since it typically requires more minimum safety distance for braking than for steering to avoid a frontal collision. Evasive steering assist (ESA) is designed to improve driver’s steer maneuver in the case of a potential imminent front collision with another vehicle or VRU. If driver initiates a steering maneuver but that steering input is not enough to avoid the collision, then evasive steering assist will kick in to apply an additional steering in the direction of the driver’s input, to help driver complete the evasive steering maneuver stably and safely. This paper discusses our recent development effort in ESA, including architecture design, path planning
Zhang, GuoguangWang, QianMujumdar, TapanSugiarto, Tanto
Field data was analyzed on second-row children in front, side and rear impacts to study fatality trends by model year (MY) and calendar year (CY) with 1980-2020 MY vehicles. The different MY and CY perspectives show changes in rates that are useful for setting priorities for second-row child safety in rear impacts. 1990 to 2019 FARS was queried to assess the number of fatally injured and non-ejected second-row children (0-15 years old) in crashes without fires. The children included outboard occupants seated behind an occupied front seat and center occupants. The data was analyzed for rear, front and side impacts to assess crash frequency. 1990-2015 POLK was queried to assess exposure of registered vehicles and estimate a fatality rate. The FARS and POLK data were sub-grouped by MY of the vehicle and CY of the crash. There were 2.8-times more fatally injured children in frontal crashes than in the rear crashes. The ratio of frontal and rear crashes varied with CY sub-groups. It was 3.9
Parenteau, ChantalViano, DavidLau, Edmund
Four crash modes are overrepresented in traffic fatalities: run-off-road crashes, non-tracking run-off-road crashes, head-on crashes, and pedestrian crashes. Two advanced driver assist systems developed to help prevent tracking run-off-road crashes and head-on crashes are lane departure warning (LDW) and lane keeping assist (LKA). LDW acts to warn the driver when they are encroaching the lane boundary, whereas LKA performs automatic steering to prevent the vehicle from departing the lane. The objective of this research was to use real-world crash data to estimate current LDW and LKA system effectiveness in reducing run-off-road crashes and cross-centerline head-on crashes. All passenger vehicles that experienced a lane departure from 2017 to 2019 in the Crash Investigation Sampling System (CISS) were analyzed. The effectivenesses of the LDW and LKA systems were computed using the quasi-induced exposure method, where the exposure group was vehicles that were rear-struck in rear-end
Dean, Morgan E.Riexinger, Luke E.
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