Browse Topic: Crash research

Items (475)
With the capability of predicting detailed injury of occupants, the Human Body Model (HBM) was used to identify potential injuries for occupants in car impact events. However, there are few publications on using HBM in the aviation industry. This study aims to investigate and compare the head, neck, lumbar spine and thoracic responses of the Hybrid III and the THUMS (Total Human Model for Safety) model in the horizontal 26g and vertical 19g sled tests required by the General Aviation Aircraft Airworthiness Regulations. The HIC of THUMS and Hybrid III did not exceed the requirements of airworthiness regulations. Still, THUMS had higher intracranial pressures and intracranial stresses, which could result in brain injury to the occupants. In vertical impact, the highest stress of the neck of THUMS appears at the cervical spine C2 and the upper neck is easily injured; in horizontal impact, the cervical spine C7 has the highest load, and the lower neck is easily injured. Due to the low
Shi, XiaopengDing, XiangheGuo, KaiLiu, TianfuXie, Jiang
Pelvic orientation in vehicles is crucial for preventing injuries and creating safer vehicles and restraint systems. A better understanding of pelvic orientation could provide more accurate anthropomorphic test device (ATD) models of underrepresented populations such as obese individuals, children, and small females. Sonomicrometry is the use of piezoelectric transducers that transmit ultrasound signals to each other to measure the distance between them. These signals may be aggregated using triangulation. In this experiment, ultrasound crystals were secured to the surface of a porcine surrogate to evaluate pelvic movement. This data was then processed using Sonometrics software to generate a 3D model of four static positions and three dynamic tests. The test was validated using a camera and a 3D measurement arm (CMM) to validate XYZ positions. This article discusses how this method could be helpful for developing more accurate ATD models, preventing fatalities in vehicle crashes
Mrozek, AllisonSirhan, KaterenaMacDonald, RobertDannaoui, AbdulMazloum, AishaOchocki, Katarzyna‘Dale’ Bass , Cameron R.
Drop tower testing was conducted using 50th percentile male PMHS at 15G peak acceleration in a rigid seat, with a seat pan-to-seatback angle of 90°. Subjects were instrumented with 6DOF motion blocks at T1, T4, T12, L3, and S1 to capture detailed vertebral body kinematics. Pressure sensors were also placed throughout the lumbar spine to estimate force in the intervertebral discs from S1-L2. PMHS were restrained using a pilot torso harness attached to the seat at the shoulders and lap belt, both pretensioned to 89 N. Reaction forces were measured in the seat using six-axis loads under the seat pan. Final positioning of the occupant was documented using a FARO arm point probe and laser scanner. To recreate the experimental setup, CAD models of the experimental fixture were meshed using a commercial FE modeling software (Hypermesh) and imported into LS-Dyna for incorporation with the THUMS model. The belt routing tool in LS-PrePost v4.9.12 was used to develop the torso harness and
DeWitt, Timothy R.Marcallini, Angelo M.Bolte IV, John H.Kang, Yun-Seok
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
Human body models have been used for decades to inform efforts in promoting automobile occupant and pedestrian safety. However, many of these models fail to capture the intricacies of individual variability. Cadaveric subjects typically exceed representative age ranges and hence mechanics. Animal subjects typically require specific setups that stray from that which is representative of human crash scenarios. Computational models can only consider so many practical real-world variables. Artificial surrogates, dummies being popular among them, are very popular for reusability and robust data collection. However, even the biomechanically accurate skeletal surrogates available commercially are limited in that they do not consider human variability and skeletal microstructure local variability. The objective of the work herein is to assess computational methods of metastructural variability mimicry by fabrication material. We implement mimicry approaches focusing on bulk isotropic
Hezrony, Benjamin S.C. F. Lopes, PedroBrown, Philip J.
Rear-end vehicle collisions may lead to whiplash-associated disorders (WADs), comprising a variety of neck and head pain responses. Specifically, increased axial head rotation has been associated with the risk of injuries during rear impacts, while specific tissues, including the capsular ligaments, have been implicated in pain response. Given the limited experimental data for out-of-position rear impact scenarios, computational human body models (HBMs) can inform the potential for tissue-level injury. Previous studies have considered external boundary conditions to reposition the head axially but were limited in reproducing a biofidelic movement. The objectives of this study were to implement a novel head repositioning method to achieve targeted axial rotations and evaluate the tissue-level response for a rear impact condition. The repositioning method used reference geometries to rotate the head to three target positions, showing good correspondence to reported interverbal rotations
Reis, Matheus SeifCronin, Duane
Head injuries account for 15% of snowsport-related injuries, and the majority of head impacts occur against ice or snow, low-friction surfaces. Therefore, this study aimed to evaluate how surface friction affects snowsport helmets’ oblique impact kinematics. Ten helmet models were impacted using an oblique drop tower with a 45-degree anvil and NOCSAE headform, at three locations, two surface friction conditions, and a drop speed of 5.0 m/s. Our findings indicate that friction affects peak linear acceleration, peak rotational acceleration, and peak rotational velocity during helmet impacts, with changes in post-impact rotation and impact response varying by location. Surface friction affects head impact kinematics, underscoring the need for sport-specific lab testing and emphasizing the need for friction-specific and sport-specific testing, particularly for snowsports, where surface conditions like snow and ice can alter kinematics
Stark, Nicole E.-P.Calis, AndrewWood, MatthewPiwowarski, Summer BlueDingelstedt, KristinBegonia, MarkRowson, Steve
Mitigating both neck and head injuries in the pediatric population relies heavily on improving our understanding of the underlying biomechanics of the pediatric cervical spine. The tensile response for individual motion segments and the whole cervical spine (WCS) has been reported, but there is no data characterizing the intersegmental kinematics of pediatric WCS under axial loading conditions. The structural response of motion segments and WCS provide valuable data for the design and validation of biofidelic physical and computational models for the pediatric population. However, the use of motion segment data to construct WCS response or the use of WCS axial response to accurately characterize intersegmental response may present limitations to accurately modeling the pediatric cervical spine response. In this secondary analysis of the work of Luck et al. (2008, 2013), the fixed-fixed, low load, quasi-static tensile response of the WCS and individual motion segments (O-C2, C4-C5, and
Liu, MirandaLuck, Jason F.
Thorax injuries are a significant cause of mortality in automotive crashes, with varying susceptibility across sex and age demographics. Finite element (FE) human body models (HBMs) offer the potential for injury outcome analysis by incorporating anthropometric variations. Recent advancements in material constitutive models, cortical bone fracture and continuum damage mechanics model (CFraC) and an orthotropic trabecular bone model (OrthoT), offer the opportunity to further improve rib models. In this study, the CFraC and OrthoT material modes, coupled with age-specific material properties, were progressively implemented to the Global Human Body Model Consortium small female 6th rib. Four distinct 6th rib models were developed and compared against sex and age-specific experimental data. The updated material models notably refined the predictions of force–displacement responses, aligning them more closely with the experimental averages. The CFraC model significantly improved the
Corrales, Miguel A.Holcombe, SvenAgnew, Amanda M.Kang, Yun-SeokMarkusic, CraigSugaya, HisakiCronin, Duane S.
Ongoing research in simulated vehicle crash environments utilizes postmortem human subjects (PMHS) as the closest approximation to live human response. Lumbar spine injuries are common in vehicle crashes, necessitating accurate assessment methods of lumbar loads. This study evaluates the effectiveness of lumbar intervertebral disc (IVD) pressure sensors in detecting various loading conditions on component PMHS lumbar spines, aiming to develop a reliable insertion method and assess sensor performance under different loading scenarios. The pressure sensor insertion method development involved selecting a suitable sensor, using a customized needle-insertion technique, and precisely placing sensors into the center of lumbar IVDs. Computed tomography (CT) scans were utilized to determine insertion depth and location, ensuring minimal tissue disruption during sensor insertion. Tests were conducted on PMHS lumbar spines using a robotic test system for controlled loading in flexion
Burns, Michael R.Caldwell, A. JamesShin, JeesooSochor, Sara H.Kopp, Kevin P.Shaw, GregGepner, BronislawKerrigan, Jason R.
Exploring the mechanical properties of soft tissues under compressive loading is crucial for understanding their role in automobile incidents. Soft tissues, which serve as cushions or padding between bone and vehicle interiors, significantly influence contact duration and forces, thereby altering incident kinematics and injury. In this investigation, muscle and soft connective tissues from post-mortem human subjects (PMHS) forearms were excised and subjected to compression and indentation testing methods at various rates and strains. Specific samples with higher proportions of muscle were compared against samples without muscle tissues to evaluate the role of compositional changes. Anthropomorphic test device (ATD) upper extremity foam and vinyl–foam composite analog tissues underwent similar testing for comparison. High impact rates simulating those in high-speed automotive collisions were achieved using a custom-built drop tower impactor setup. The results revealed significantly
Dennis, Cole J.Quenneville, Cheryl E.
Extreme out-of-position pre-crash postures may need high-force pre-pretensioner (PPT) for effective repositioning (Mishra et al., 2023). To avoid applying a high force on the chest, we hypothesized that in case of these extreme postures the PPT may be activated in the absence of a pre-crash motion as a cautionary measure. Therefore, the aims of this study were: (1) to understand the effect of the PPT in repositioning a forward-leaning occupant in static conditions and (2) to characterize occupants’ kinematic variability during repositioning. Sixteen healthy volunteers (8 males, 8 females, 23.8 ± 4.2 years old) were seated with a 40° forward posture on a vehicle seat and restrained with a 3-point seat belt equipped with a PPT. Two PPT seatbelt conditions were examined: low PPT (100 N) and high PPT (300 N). Head and trunk rearward displacements relative to the initial forward-leaning position at 350 ms from PPT onset were collected with a 3D motion-capture system and compared between
Witmer, MaitlandGriffith, MadelineGraci, Valentina
Fragility fracture of the hip is a global health concern with generally poor outcomes. Clinical studies have shown prophylactic augmentation of the femur to be a plausible intervention with success in some approaches; however, its use is not yet widespread in the clinical community. We aimed to evaluate the efficacy and clinical safety of prophylactic intramedullary nailing for hip fracture prevention after a fall impact in six cadaveric pelvis–femurs. Post-fall fracture status of the native specimens was determined in a virtual control group built using a validated and peer-reviewed finite element method. A commercially available intramedullary nailing system was prophylactically implanted in all specimens. After augmentation, specimens were subjected to an experimental sideways fall impact and inspected for fracture. Overall, fracture status was unchanged or lowered in severity in the augmented group compared to the native control group. No sign of femur fracture was found in the
Bliven, Emily K.Fung, AnitaBaker, AlexanderHelgason, BenediktGuy, PierreCripton, Peter A.
Athletes may sustain numerous head impacts during sport, leading to potential neurological consequences. Wearable sensors enable real-world head impact data collection, offering insight into sport-specific brain injury mechanisms. Most instrumented mouthguard studies focus on a single sport, lacking a quantitative comparison of head impact biomechanics across sports. Additionally, direct comparison of prior studies can be challenging due to variabilities in methodology and data processing. Therefore, we gathered head impact data across multiple sports and processed all data using a uniform processing pipeline to enable direct comparisons of impact biomechanics. Our aim was to compare peak kinematics, impulse durations, and head impact directionality across ice hockey, American football, rugby, and soccer. We found that American football had the highest magnitude of head impact kinematics and observed directionality differences in linear and angular kinematics between sports. On the
Masood, Zaryan Z.Luke, David S.Kenny, Rebecca A.Bondi, Daniel R.Clansey, Adam C.Wu, Lyndia C.
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
University of Waterloo Chemical Engineering Researcher Dr. Elisabeth Prince teamed up with researchers from the University of Toronto and Duke University to design the synthetic material made using cellulose nanocrystals, which are derived from wood pulp. The material is engineered to replicate the fibrous nanostructures and properties of human tissues, thereby recreating its unique biomechanical properties
The increased use of computational human models in evaluation of safety systems demands greater attention to selected methods in coupling the model to its seated environment. This study assessed the THUMS v4.0.1 in an upright driver posture and a reclined occupant posture. Each posture was gravity settled into an NCAC vehicle model to assess model quality and HBM to seat coupling. HBM to seat contact friction and seat stiffness were varied across a range of potential inputs to evaluate over a range of potential inputs. Gravity settling was also performed with and without constraints on the pelvis to move towards the target H-Point. These combinations resulted in 18 simulations per posture, run for 800 ms. In addition, 5 crash pulse simulations (51.5 km/h delta V) were run to assess the effect of settling time on driver kinematics. HBM mesh quality and HBM to seat coupling metrics were compared at kinetically identical time points during the simulation to an end state where kinetic
Wade von Kleeck, B.Caffrey, JulietteWeaver, Ashley A.Gayzik, F. ScottHallman, Jason
The advent of neck braces for the helmeted motorcycle rider has introduced a pertinent research question: To what extent do they reduce measures related to the major mechanism of neck injury in unrestrained torso accidents, i.e., compression flexion (CF)? This question requires a suitable method of testing and evaluating the measures for a load case resulting in the required mechanism. This study proposes a weighted swinging anvil striking the helmeted head of a supine HIII ATD by means of a near vertex impact with a low degree of anterior head impact eccentricity to induce CF of the neck. The applied impact was chosen for the baseline (no neck brace) so that the upper and lower neck axial forces approached injury assessment reference values (IARV). The head impact point evaluated represents those typically associated with high-energy burst fractures occurring within the first 20 ms, with possible secondary disruption of posterior ligaments. The proposed test can be used to evaluate
de Jongh, Cornelis U.Basson, Anton H.Knox, Erick H.Leatt, Christopher J.
Animal–vehicle collisions (AVCs) can result in devastating injuries to both humans and animals. Despite significant advances in crash prediction models, there is still a significant gap when it comes to injury severity prediction models in AVCs, especially concerning small animals. It is no secret that large mammals can pose a significant threat to road safety; however, researchers tend to overlook the impact of domestic and small animals wandering along the roads. In this study, STATS19 road safety data was used containing any type of live animal, and a radial basis function (RBF) model was used to predict different severities of injury regardless of whether the animal was hit, or not. As a means of better understanding the factors contributing to severities, regression trees were used to identify and retain only the most useful predictors, removing the less useful ones. A comparison was made between the performance of the trees across a range of severity classes, and the model
Siami Doudaran, MeisamKonuralp, Hilmiye
Scientists at Osaka University, in cooperation with Joanneum Research (Weiz, Austria), have introduced wireless health monitoring patches that use embedded piezoelectric nanogenerators to power themselves with harvested biomechanical energy. This work may lead to new autonomous health sensors as well as battery-less wearable electronic devices
With population aging and life expectancy increasing, elderly drivers have been increasing quickly in the United States and the heterogeneity among them with age is also increasingly non-ignorable. Based on traffic crash data of Pennsylvania from 2011 to 2019, this study was designed to identify this heterogeneity by quantifying the relationship between age and crash characteristics using linear regression. It is found that for elderly driver-involved crashes, the proportion leading to casualties significantly increases with age. Meanwhile, the proportions at night, on rainy days, on snowy days, and involving driving under the influence (DUI) decrease linearly with age, implying that elderly drivers tend to avoid traveling in risky scenarios. Regarding collision types, elderly driver-involved crashes are mainly composed of angle, rear-end, and hit-fixed-object collisions, proportions of which increase linearly, decrease linearly, and keep consistent with age, respectively. The increase
Zhang, ZihaoLiu, Chenhui
For taking counter measures in advance to prevent accidental risks, it is of significance to explore the causes and evolutionary mechanism of ship collisions. This article collects 70 ship collision accidents in Zhejiang coastal waters, where 60 cases are used for modeling while 10 cases are used for verification (testing). By analyzing influencing factors (IFs) and causal chains of accidents, a Bayesian network (BN) model with 19 causal nodes and 1 consequential node is constructed. Parameters of the BN model, namely the conditional probability tables (CPTs), are determined by mathematical statistics methods and Bayesian formulas. Regarding each testing case, the BN model’s prediction on probability of occurrence is above 80% (approaching 100% indicates the certainty of occurrence), which verifies the availability of the model. Causal analysis based on the backward reasoning process shows that H (Human error) is the main IF resulting in ship collisions. The causal chain that maximizes
Tian, YanfeiQiao, HuiHua, LinAi, Wanzheng
Compared to other age groups, older adults are at more significant risk of hip fracture when they fall. In addition to the higher risk of falls for the elderly, fear of falls can reduce this population’s outdoor activity. Various preventive solutions have been proposed to reduce the risk of hip fractures ranging from wearable hip protectors to indoor flooring systems. A previously developed rubberized asphalt mixture demonstrated the potential to reduce the risk of head injury. In the current study, the capability of the rubberized asphalt sample was evaluated for the risk of hip fracture for an average elderly male and an average elderly female. A previously developed human body model was positioned in a fall configuration that would give the highest impact forces toward regular asphalt. Three different rubber contents with 14, 28, 33 weight percent (% wt.) were implemented as the ground alongside one regular non-rubberized (0%) asphalt mixture, one baseline, and one extra-compliant
Sahandifar, PooyaWallqvist, VivecaKleiven, Svein
A research program has been launched in Iran to develop an evaluation method for comparing the safety performance of vehicles in real-world collisions with crash test results. The goal of this research program is to flag vehicle models whose safety performance in real-world accidents does not match their crash test results. As part of this research program, a metric is needed to evaluate the severity of side impacts in crash tests and real-world accidents. In this work, several vehicle-based metrics were analyzed and calculated for a dataset of more than 500 side impact tests from the NHTSA crash test database. The correlation between the metric values and the dummy injury criteria was studied to find the most appropriate metric with the strongest correlation coefficient values with the dummy injury criteria. Delta-V and a newly created metric T K 200 Y , which is an indicator of the kinetic energy transferred to occupants in a 200 ms time interval and in the lateral direction, were
Sadeghipour, Emad
Letter from the Special Issue Editors
Mueller, BeckyBautsch, BrianMansfield, Julie
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.
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.
The human body models consisting of bone, soft tissue, and skin were created based on the latest anthropometry data. The mechanical modeling of vehicle seat cover was studied, as well as the simulation of human-seat interface pressure. As a case study, the seat finite element (FE) model was established using the real-vehicle seat geometric data considering the condition with and without seat cover. The seat and body were assembled to conduct the simulation of human-seat interface pressure. By comparing the simulative result with those of the test, the accuracy of the simulation and the important role of cover material in body pressure simulation were validated. The result also showed that the cover material could not be ignored in the simulation of human-seat interface pressure. The method of interface pressure simulation presented in this article is a systematic and useful way of predicting the human-seat interface pressure, which can be further used for functional verification and
Zhang, TianmingRen, JindongQi, ShiminYuan, BaoguoHuang, Hao
The purpose and scope of this SAE Recommended Practice is to provide a basis for classification of the extent of vehicle deformation caused by vehicle accidents on the highway. It is necessary to classify collision contact deformation (as opposed to induced deformation) so that the accident deformation may be segregated into rather narrow limits. Studies of collision deformation can then be performed on one or many data banks with assurance that the data under study are of essentially the same type.1 The seven-character code is also an expression useful to persons engaged in automobile safety, to describe appropriately a field-damaged vehicle with conciseness in their oral and written communications. Although this classification system was established primarily for use by professional teams investigating accidents in depth, other groups may also find it useful. The classification system consists of seven characters, three numeric, and four alphameric, arranged in a specific order. The
Crash Data Collection and Analysis Standards Committee
The THOR-AV dummy is a modified THOR dummy being developed for occupant safety testing in upright and reclined seating postures. The dummy has a new neck with improved biofidelity in rear impact, a pelvis/abdomen/lumbar design to improve seating posture, and a pelvis anthropometry that mimics human submarining responses for reclined seat testing. The dummy was evaluated against postmortem human subject (PMHS) corridors in rearward facing impact conditions (56 km/h impact speed, 38g acceleration) in both 25° and 45° seatback configurations. Biofidelity Ranking System (BRS) scores were calculated in accordance with NHTSA’s latest calculation algorithm. The BRS scores for THOR-AV seat loading are 1.58 (“good” biofidelity) and 2.94 (“marginal” biofidelity) for the 25° and 45° configurations respectively. The BRS scores for THOR-AV occupant responses are 1.95 and 1.38 for the 25° and 45° configurations respectively, both corresponding to “good” biofidelity. From the evaluation, the dummy
Wang, Zhenwen Jerry
The biomechanical injury assessment for an occupant in a planar vehicle-to-vehicle collision often requires a kinematic analysis of impact-related occupant motion. This analysis becomes more complex when the collision force is eccentric to the center of gravity on a struck vehicle because the vehicle kinematics include both translation and potentially significant yaw rotational rates. This study examines the significance of vehicle yaw on occupant kinematics in eccentric (off-center) planar collisions. The paper describes the calculation of the instantaneous center of rotation (ICR) in a yawing vehicle post-impact and explores how mapping this quantity may inform an occupant’s trajectory when using a free particle “occupant” analysis. The study initially analyzed the impact-related occupant motion for all the outboard seat positions in a minivan using several hypothetical examples of eccentric vehicle-to-vehicle crash configurations with varying PDOF, delta-V, and yaw rate. The ICR and
Rapp van Roden, ElizabethZolock, John
Many motorcycle crashes involve the motorcycle capsizing, impacting the ground, and sliding on the road surface. When performing speed calculations, the energy or speed loss for the ground impact and sliding phases may need to be calculated. To perform these calculations, the reconstructionist will typically determine the slide distance based on the physical evidence and then apply a range of decelerations over that distance based on test data in the literature. Decelerations can be selected for motorcycles with similar characteristics (crash bars, panniers, fairings, etc.) sliding on similar surfaces (asphalt, concrete, dirt, gravel, etc.). This approach is adequate but sometimes results in a wide range due to the variability in reported decelerations in prior studies. It could be helpful to narrow the likely range of decelerations, and thus, the speed range. Many past studies, however, describe their tests with inadequate detail to parse out precisely what factors were most
Rose, NathanPalmer, JacobSmith, ConnorCarter, NealWalter, Kevin
Field accident data and vehicle crash and sled testing indicate that occupant kinematics, loading, and associated injury risk generally increase with crash severity. Further, these data demonstrate that the use of restraints, such as three-point belts, provides mitigation of kinematics and reduction in loading and injury potential. This study evaluated the role of seat belts in controlling occupant kinematics and reducing occupant loading in moderate severity frontal collisions. Frontal tests with belted and unbelted anthropomorphic test devices (ATDs) in the driver and right front passenger seats were performed at velocity changes (delta-Vs) of approximately 19 kph (12 mph) and 32 kph (20 mph) without airbag deployment. At the lower-moderate severity (19 kph), motion of the belted ATDs was primarily arrested by seat belt engagement, while motion of the unbelted ATDs was primarily arrested by interaction with forward vehicle structures. Occupant loading and injury risk was generally
Isaacs, Jessica L.George, JuffCampolettano, EamonCutcliffe, HattieMiller, Bruce
Exoskeletons, many of which are powered by springs or motors, can cause pain or injury if their joints are not aligned with the user’s. To mitigate these risks, a new measurement method was developed to test whether an exoskeleton and the person wearing it are moving smoothly and in harmony
We recently developed a three-direction (vertical, longitudinal, and lateral) coupled biodynamic model of seated posture under vibration. However, in that study we only tested one algorithm to identify the model parameters. This article investigates four different optimization solvers in Matlab®, i.e., particle swarm optimization (particleswarm), particle swarm and local optimization method (fmincon), genetic algorithm (ga) and local optimization method (fmincon), and local optimization method (fmincon) to identify coupled biodynamic model parameters. Based on the obtained parameters, it further compares experimental and simulation results to determine the best optimization solver in terms of the root mean square error (RMSE), linear regression (R 2), goodness of fit (ε), and Central Processing Unit (CPU) time. The results show that particle swarm optimization is the best one for identifying the biodynamic model’s parameters
Yang, YanwenZhao, QinghaiYang, James
Reliable online recognition and prediction of human actions and activities in temporal sequences has many potential applications in a wide range of Army-relevant fields, ranging from video surveillance, warfighter assistance, human computer interface, intelligent humanoid robots, and unmanned and autonomous vehicles, to diagnosis, assessment and treatment of musculoskeletal disorders, etc. A computational approach for action prediction can extend these findings to machines and also promote further research in human prediction and intention sensing
Monitoring the progression of multiple sclerosis-related gait issues can be challenging in adults over 50 years old, requiring a clinician to differentiate between problems related to MS and other age-related issues. To address this problem, researchers integrated gait data and machine learning to advance the tools used to monitor and predict disease progression
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