前碰撞中髋关节姿态对乘员骨盆骨折影响的数值研究

A Numerical Investigation into the Influence of Hip Posture on Occupant Pelvis Fracture in Vehicle Frontal Impact

本文旨在建立一种在汽车前碰撞中乘员骨盆损伤评价的虚拟试验方法,以便为乘员安全设计提供相关的生物力学参数。基于LS-DYNA和某一50百分位美国男性下肢解剖学结构信息,建立了一个较为精细的乘员下肢有限元模型,并通过骨盆侧向冲击和膝-大腿-髋部的膝部轴向冲击模拟试验验证了模型的有效性。对该模型进行了虚拟试验,以研究不同屈曲角和外展角的髋关节姿态对骨盆在前碰撞的失效值的影响。结果表明:由于髋臼壁各受力点强度的不同,膝部轴向冲击下的骨盆损伤部位和失效值也随着髋关节姿态的改变而变化。随着髋关节屈曲角和外展角的增大,骨盆损伤部位由髂骨转移到髋臼;骨盆失效值随屈曲角的增加而增大;而随外展角的增加先增大后减小。研究结果为汽车前碰撞安全设计中的乘员骨盆损伤评价提供了参考依据。

This paper aims to develop a virtual test method for assessing occupant pelvis injury in vehicle frontal crash, in order to provide relevant biomechanical parameters for occupant safety design. Accordingly, based on the anatomical structure information of a 50th percentile American male and using LS-DYNA code, a relatively refined finite element model for occupant lower extremity is created with its effectiveness verified by the simulation tests of side impact on pelvis and axial impact on knee-thigh-hip complex. Then a series of virtual tests are conduc-ted on the model to investigate the influence of hip posture with different flexion angles and abduction angles on the failure force of pelvis. The results show that the pelvis fracture location and failure force under axial impact on knee depend on hip posture due to the different strength of various loaded points on acetabulum wall. With the increase of thigh flexion and abduction angles, pelvis fracture location shifts from ilium to acetabulum. The failure force of pel-vis goes up with the increase of thigh flexion angle, while it goes up first and then falls down with the rise of thigh abduction angle. The findings of this study provide a reference basis for pelvis injury assessment in vehicle frontal crash safety design.