Evaluation of biofidelity of THUMS pedestrian model under a whole-body impact conditions with a generic sedan buck

ABSTRACT Objective: The goal of this study was to evaluate the biofidelity of the Total Human Model for Safety (THUMS; Ver. 4.01) pedestrian finite element models (PFEM) in a whole-body pedestrian impact condition using a well-characterized generic pedestrian buck model. Methods: The biofidelity of THUMS PFEM was evaluated with respect to data from 3 full-scale postmortem human subject (PMHS) pedestrian impact tests, in which a pedestrian buck laterally struck the subjects using a pedestrian buck at 40 km/h. The pedestrian model was scaled to match the anthropometry of the target subjects and then positioned to match the pre-impact postures of the target subjects based on the 3-dimensional motion tracking data obtained during the experiments. An objective rating method was employed to quantitatively evaluate the correlation between the responses of the models and the PMHS. Injuries in the models were predicted both probabilistically and deterministically using empirical injury risk functions and strain measures, respectively, and compared with those of the target PMHS. Results: In general, the model exhibited biofidelic kinematic responses (in the Y–Z plane) regarding trajectories (International Organization for Standardization [ISO] ratings: Y = 0.90 ± 0.11, Z = 0.89 ± 0.09), linear resultant velocities (ISO ratings: 0.83 ± 0.07), accelerations (ISO ratings: Y = 0.58 ± 0.11, Z = 0.52 ± 0.12), and angular velocities (ISO ratings: X = 0.48 ± 0.13) but exhibited stiffer leg responses and delayed head responses compared to those of the PMHS. This indicates potential biofidelity issues with the PFEM for regions below the knee and in the neck. The model also demonstrated comparable reaction forces at the buck front-end regions to those from the PMHS tests. The PFEM generally predicted the injuries that the PMHS sustained but overestimated injuries in the ankle and leg regions. Conclusions: Based on the data considered, the THUMS PFEM was considered to be biofidelic for this pedestrian impact condition and vehicle. Given the capability of the model to reproduce biomechanical responses, it shows potential as a valuable tool for developing novel pedestrian safety systems.

[1]  Ivan Prebil,et al.  Failure properties and damage of cervical spine ligaments, experiments and modeling. , 2014, Journal of biomechanical engineering.

[2]  Masami Iwamoto,et al.  DEVELOPMENT OF A FINITE ELEMENT MODEL OF THE TOTAL HUMAN MODEL FOR SAFETY (THUMS) AND APPLICATION TO INJURY RECONSTRUCTION , 2002 .

[3]  Jason R. Kerrigan,et al.  Dynamic Response Corridors and Injury Thresholds of the Pedestrian Lower Extremities , 2004 .

[4]  Ren-Jye Yang,et al.  Objective Rating Metric for Dynamic Systems , 2013 .

[5]  Roger C. Haut,et al.  Determination of ligament strain during high ankle sprains due to excessive external foot rotation in sports , 2012 .

[6]  Jeffrey Richard Crandall,et al.  Component‐level Biofidelity Assessment of Morphed Pedestrian Finite Element Models , 2015 .

[7]  B. Winkelstein,et al.  Cervical facet capsular ligament yield defines the threshold for injury and persistent joint-mediated neck pain. , 2007, Journal of biomechanics.

[8]  Pierre Jean Arnoux,et al.  Investigation of the injury threshold of knee ligaments by the parametric study of car–pedestrian impact conditions , 2014 .

[9]  Jess G Snedeker,et al.  Assessment of pelvis and upper leg injury risk in car-pedestrian collisions: comparison of accident statistics, impactor tests and a human body finite element model. , 2003, Stapp car crash journal.

[10]  J. Stitzel,et al.  Injury prediction in a side impact crash using human body model simulation. , 2014, Accident; analysis and prevention.

[11]  Richard Kent,et al.  Chest deflection tolerance to blunt anterior loading is sensitive to age but not load distribution. , 2005, Forensic science international.

[12]  Rikard Fredriksson,et al.  Development and Component Validation of a Generic Vehicle Front Buck for Pedestrian Impact Evaluation , 2014 .

[13]  Johan Davidsson,et al.  Head Kinematics and Shoulder Biomechanics in Shoulder Impacts Similar to Pedestrian Crashes—A THUMS Study , 2015, Traffic injury prevention.

[14]  Rahul Goyal,et al.  Repositioning the Knee Joint in Human Body FE Models Using a Graphics-Based Technique , 2012, Traffic injury prevention.

[15]  Rolf H Eppinger,et al.  Development of Side Impact Thoracic Injury Criteria and Their Application to the Modified ES-2 Dummy with Rib Extensions (ES-2re). , 2003, Stapp car crash journal.

[16]  Rikard Fredriksson,et al.  Full‐scale Validation of a Generic Buck for Pedestrian Impact Simulation , 2014 .

[17]  Brian Overby,et al.  Whole-body Response for Pedestrian Impact with a Generic Sedan Buck. , 2015, Stapp car crash journal.

[18]  Glenn Paskoff,et al.  Failure Properties of Cervical Spinal Ligaments Under Fast Strain Rate Deformations , 2007, Spine.

[19]  Pierre-Jean Arnoux,et al.  Injury criteria implementation and evaluation in FE models applications to lower limb segments , 2008 .

[20]  Jeffrey Richard Crandall,et al.  Pedestrian response with different initial positions during impact with a mid-sized sedan , 2015 .

[21]  Jikuang Yang,et al.  The influence of gait stance on pedestrian lower limb injury risk. , 2015, Accident; analysis and prevention.

[22]  Johan Davidsson,et al.  Which Pragmatic Finite Element Human Body Model Scaling TechniqueCan Most Accurately Predict Head Impact Conditions in Pedestrian-Car Crashes? , 2015 .

[23]  Matthew B. Panzer,et al.  Geometrical Personalization of Pedestrian Finite Element Models Using Morphing Increases the Biofidelity of Their Impact Kinematics , 2016 .

[24]  Yukou Takahashi,et al.  Examination of human body mass influence on pedestrian pelvis injury prediction using a human FE model , 2012 .

[25]  Richard W. Kent,et al.  Development of a computational framework to adjust the pre-impact spine posture of a whole-body model based on cadaver tests data. , 2015, Journal of biomechanics.

[26]  Junji Hasegawa,et al.  DEVELOPMENT OF A FINITE ELEMENT MODEL OF THE TOTAL HUMAN MODEL FOR SAFETY (THUMS) AND APPLICATION TO CAR-PEDESTRIAN IMPACTS , 2001 .

[27]  Jason Forman,et al.  Biofidelity corridors for whole‐body pedestrian impact with a generic buck , 2015 .

[28]  Rolf H Eppinger,et al.  The effects of axial preload and dorsiflexion on the tolerance of the ankle/subtalar joint to dynamic inversion and eversion. , 2002, Stapp car crash journal.

[29]  Ciaran K Simms,et al.  Assessment of model-based image-matching for future reconstruction of unhelmeted sport head impact kinematics , 2018, Sports biomechanics.

[30]  Koichi Kamiji,et al.  Pedestrian-vehicle interaction: kinematics and injury analysis of four full scale tests , 2008 .

[31]  Roger C. Haut,et al.  AXIAL COMPRESSIVE LOAD RESPONSE OF THE 90 DEGREE FLEXED HUMAN TIBIOFEMORAL JOINT , 1999 .

[32]  Jeffrey Richard Crandall,et al.  A study of the pedestrian impact kinematics using finite element dummy models: the corridors and dimensional analysis scaling of upper-body trajectories , 2008 .

[33]  James T. Patrie,et al.  Tolerance of the human leg and thigh in dynamic latero-medial bending , 2004 .

[34]  T. Yasuki,et al.  Research of the relationship of pedestrian injury to collision speed, car-type, impact location and pedestrian sizes using human FE model (THUMS Version 4). , 2012, Stapp car crash journal.

[35]  Yasuo Yamamae,et al.  Validation of kinematics and lower extremity injuries estimated by total human model for safety in SUV to pedestrian impact test , 2010 .