为了深入研究汽车-行人碰撞过程中下肢的生物力学响应和损伤机理,基于人体解剖学结构建立了具有完整下肢组织结构和高仿生精度的成年男性行人下肢有限元模型.包括股骨、胫骨、腓骨、髌骨等下肢骨骼以及皮肤、肌肉、韧带、关节囊、半月板等重要软组织.针对长骨骨干断面几何不均匀的特征,提出以CT断面影像数据为依据,建立以真实皮质骨内外表面为边界实现皮质骨断面厚度和形状连续变化的长骨数值模型,对不同建模方式进行了对比,采用两层实体单元模拟皮质骨以获得相对较高的计算精度和计算效率.通过模拟相关生物力学实验,获得了行人下肢各部位的损伤参数,分析了皮质骨厚度变化以及不同撞击方向对下肢损伤参数和损伤机理的影响.上述损伤参数的获得可为我国汽安全性设计提供参考. In order to further study the biomechanical response and injury mechanism of the lower limbs during the car-pedestrian collision, a finite element model of adult male pedestrians with intact lower limbs and high bionic accuracy was established based on human anatomy, including the femur, tibia, fibula, Patella and other lower limb bones and skin, muscle, ligaments, joint capsule, meniscus and other important soft tissue.Because of the feature of uneven geometry of the long bone, we propose to use cortical CT data to establish the cortex The long bone numerical model with continuously changing thickness and shape of bone section was used to compare the different modeling methods and the two-layer solid unit was used to simulate the cortical bone to obtain relatively high accuracy and computational efficiency.By simulating the related biomechanical experiments, The damage parameters of lower extremity and the damage mechanism of lower extremity were analyzed by the change of cortical bone thickness and the impact direction of different crabs.The acquisition of the above damage parameters can provide a reference for the design of steam safety in our country.