Modeling And Application Of A China 50 Percentile Pedestrian Lower Limb Finite Element Model

In car-pedestrian collision accident,the lower limb is the first site to be impacted,thus suffers a greater risk of injury.Although lower limb injuries are generally not fatal,they can cause long-term pain to the victim and bring a heavy financial burden.Pedestrian protection in China started late,and relevant pedestrian protection regulations were formulated with reference to foreign regulations.In particular,the impactor used for the New Car Assessment Program(NCAP)are designed with reference to foreign human body sizes,which lead to the related that pedestrian protection research may not protect Chinese pedestrians.At the same time,some studies have proved that the active muscle plays an important role in human body collision damage.According to the above introduction,this paper mainly completes the following work:Firstly,a large number of anthropometric data were investigated,and the differences of lower limb measurement data between Chinese ? European and American people in 5,50 and 95 percentiles were quantitatively compared.Then,the posture was adjusted on the basis of the existing occupant model,and the dynamic response of the finite element model of lower limbs in collision was improved by adding fat tissue.Then,based on classical biomechanical experiments,the improved finite element model is verified from isolated tissues to sub-segments and the whole lower limb.Finally,using the case of collision with the car,the difference in response with the THUMS model was compared and the difference between the response of the muscle activation and the inactive model was compared.By analyzing and comparing anthropometric data,it is found that there are differences in lower limb measurement between Chinese,European and American,especially the difference between Chinese and Americans in calf data is about 10%.The results of model validation show that the improved finite element model has better kinematic and biomechanical responses.The simulation results are basically consistent with the experimental results.The model can be used for pedestrian lower limb injury analysis.Compared with the response of THUMS model,it is found that the pedestrian kinematics response is significantly different due to their different heights,and the knee joint injury parameters are also different,so the influence of height difference on pedestrian injury should not be ignored.By comparing the responses of muscle activation and inactivation models,it was found that muscle active force had little effect on kinematic response,but muscle active force could slow down the change of knee joint shear displacement and provide some protection for pedestrians.These results will provide some reference for Pedestrian Lower Limb Protection and research direction in the future.