Analysis of the influence of passenger vehicles front-end design on pedestrian lower extremity injuries by means of the LLMS model

ABSTRACT Objective: This work aims at investigating the influence of some front-end design parameters of a passenger vehicle on the behavior and damage occurring in the human lower limbs when impacted in an accident. Methods: The analysis is carried out by means of finite element analysis using a generic car model for the vehicle and the lower limbs model for safety (LLMS) for the purpose of pedestrian safety. Considering the pedestrian standardized impact procedure (as in the 2003/12/EC Directive), a parametric analysis, through a design of experiments plan, was performed. Various material properties, bumper thickness, position of the higher and lower bumper beams, and position of pedestrian, were made variable in order to identify how they influence the injury occurrence. The injury prediction was evaluated from the knee lateral flexion, ligament elongation, and state of stress in the bone structure. Results: The results highlighted that the offset between the higher and lower bumper beams is the most influential parameter affecting the knee ligament response. The influence is smaller or absent considering the other responses and the other considered parameters. The stiffness characteristics of the bumper are, instead, more notable on the tibia. Even if an optimal value of the variables could not be identified trends were detected, with the potential of indicating strategies for improvement. Conclusions: The behavior of a vehicle front end in the impact against a pedestrian can be improved optimizing its design. The work indicates potential strategies for improvement. In this work, each parameter was changed independently one at a time; in future works, the interaction between the design parameters could be also investigated. Moreover, a similar parametric analysis can be carried out using a standard mechanical legform model in order to understand potential diversities or correlations between standard tools and human models.

[1]  King H Yang,et al.  A field data analysis of risk factors affecting the injury risks in vehicle-to-pedestrian crashes. , 2008, Annals of advances in automotive medicine. Association for the Advancement of Automotive Medicine. Annual Scientific Conference.

[2]  L Thollon,et al.  Pedestrian Lower Limb Injury Criteria Evaluation: A Finite Element Approach , 2005, Traffic injury prevention.

[3]  Massimiliano Avalle,et al.  Stochastic Crash Analysis of Vehicle Models For Sensitivity Analysis and Optimization , 2007 .

[4]  Jikuang Yang,et al.  Safer passenger car front shapes for pedestrians: A computational approach to reduce overall pedestrian injury risk in realistic impact scenarios. , 2017, Accident; analysis and prevention.

[5]  Dietmar Otte,et al.  The influence of passenger car front shape on pedestrian injury risk observed from German in-depth accident data. , 2017, Accident; analysis and prevention.

[6]  Luis Martínez,et al.  Influence of vehicle shape and stiffness on the pedestrian lower extremity injuries: review of current pedestrian lower leg test procedure , 2008 .

[7]  Peter Schuster Current Trends in Bumper Design for Pedestrian Impact , 2006 .

[8]  D. K. Park,et al.  Optimum SUV bumper system design considering pedestrian performance , 2010 .

[9]  Jikuang Yang,et al.  Optimization of Bumper System for Pedestrian Lower Leg Protection from Vehicle Impact , 2012, 2012 Third International Conference on Digital Manufacturing & Automation.

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

[11]  C Haasper,et al.  Characteristics on fractures of tibia and fibula in car impacts to pedestrians and bicyclists - influences of car bumper height and shape. , 2007, Annual proceedings. Association for the Advancement of Automotive Medicine.

[12]  Bernard Laumon,et al.  Pedestrian injury patterns according to car and casualty characteristics in france. , 2011, Annals of advances in automotive medicine. Association for the Advancement of Automotive Medicine. Annual Scientific Conference.

[13]  Jason R. Kerrigan,et al.  Pedestrian Lower Extremity Response and Injury: A Small Sedan vs. A Large Sport Utility Vehicle , 2008 .

[14]  Heng Tao Shen,et al.  Principal Component Analysis , 2009, Encyclopedia of Biometrics.

[15]  Tsai-Jeon Huang,et al.  Design of a bumper system for pedestrian lower-leg protection using the Taguchi method , 2011 .

[16]  N. D. Grew,et al.  The Influence of Car Design on Pedestrian Protection , 1985 .

[17]  Dominique Cesari,et al.  Pedestrian-Vehicle Accident: Analysis of 4 Full Scale Tests with PMHS , 2007 .

[18]  Tsuyoshi Yasuki Mechanism analysis of pedestrian knee-bending angle by sedan-type vehicle using human FE model , 2007 .

[19]  Clive Neal-Sturgess,et al.  APROSYS in-depth database of serious pedestrian and cyclist impacts with vehicles , 2008 .

[20]  J Kajzer,et al.  Simulation of car impact to pedestrian lower extremity: influence of different car-front shapes and dummy parameters on test results. , 1994, Accident; analysis and prevention.

[21]  Tsuyoshi Yasuki An Analysis of Lower Leg Impactor Behavior by Physics Model , 2008 .

[22]  A. R. Noorpoor,et al.  Lower extremity injuries in vehicle-pedestrian collisions using a legform impactor model , 2010 .

[23]  Dominique Cesari,et al.  The failure modelling of knee ligaments in the finite element model , 2012 .

[24]  Dominique Cesari,et al.  Coupling Lateral Bending and Shearing Mechanisms to Define Knee Injury Criteria for Pedestrian Safety , 2013, Traffic injury prevention.

[25]  T Yasuki Mechanism analysis of pedestrian knee-bending angle by SUV type vehicles using human FE model , 2007 .

[26]  Xuejun Liu,et al.  A Study of Influences of Vehicle Speed and Front Structure on Pedestrian Impact Responses Using Mathematical Models , 2002 .

[27]  D S McNally,et al.  The effect of leg fracture level and vehicle front-end geometry on pedestrian knee injury and response , 2006, Proceedings of the Institution of Mechanical Engineers. Part H, Journal of engineering in medicine.

[28]  S. M. Sapuan,et al.  Conceptual design of a polymer composite automotive bumper energy absorber , 2008 .

[29]  Catherine Masson,et al.  Injury tolerance of tibia for the car-pedestrian impact. , 2012, Accident; analysis and prevention.

[30]  A. R. Noorpoor,et al.  Investigation on the Effect of Impact Location Height on Pedestrian Safety using a Legform Impactor Dynamic Model , 2010 .

[31]  Pierre Jean Arnoux,et al.  Knee ligament failure under dynamic loadings , 2002 .

[32]  Ted Belytschko,et al.  Elastic crack growth in finite elements with minimal remeshing , 1999 .

[33]  A I King,et al.  Lower Limb: Advanced FE Model and New Experimental Data. , 2001, Stapp car crash journal.

[34]  Akira Sasaki,et al.  CURRENT SITUATION OF PEDESTRIAN ACCIDENTS AND RESEARCH INTO PEDESTRIAN PROTECTION IN JAPAN , 1991 .

[35]  Jin Ho Choi,et al.  Development of the composite bumper beam for passenger cars , 1995 .

[36]  Pierre Jean Arnoux,et al.  Incidences of various passenger vehicle front-end designs on pedestrian lower limb injuries , 2015 .

[37]  Y Mizuno International harmonized research activities (ihra) status report of the pedestrian safety working group , 1998 .