有限元法研究高坠中躯干不同部位着地的肋骨骨折机制

Exploring of the Mechanism of Rib Fracture Caused by Landing on Different Parts of the Trunk after Falls from Height Using Finite Element Method

目的利用有限元法研究躯干不同部位着地的肋骨损伤机制,对重建高坠过程提供新技术与新方法。方法采用有限元法观察全人类安全模型THUMS4.0在躯干部不同部位着地时的肋骨损伤情况,并与实际案例进行比较,从生物力学角度分析高坠导致的肋骨骨折形成机制。结果不同部位着地所形成的应力、应变分布及肋骨骨折部位存在一定差异。躯干前侧着地时双侧均发生肋骨骨折,骨折主要位于肋骨-肋软骨交界处和腋中线区域;躯干右前侧着地时,着地一侧首先发生肋骨骨折,骨折分布于右侧腋中线至腋后线区域以及双侧肋骨-肋软骨交界处;躯干后侧着地时,骨折主要位于双侧肋骨后侧;躯干右后侧着地时,着地部位易发生多发性肋骨骨折。塑性应变多集中于骨折处,von Mises应力除集中于骨折处,也可位于其他部位。结论躯干部不同部位着地时,肋骨骨折部位及损伤机制具有一定差异。

Objective To study the mechanism of rib fracture caused by landing on different parts of the trunk using finite element method,and to provide some new techniques and new ideas for the reconstruction of the whole process of falls from height.Methods The finite element method was used to study the rib fracture of human security model THUMS4.0 caused by landing on different parts of the trunk.Then the model was compared with actual cases and the mechanism of rib fracture caused by falls from height was analyzed from a biomechanical point of view.Results There were some differences in the stress and strain distribution as well as the rib fracture sites when different parts touched the ground.Ribs on both sides of the body were fractured when the front of the trunk touched the ground,and the fractures were mainly located in the junction of the ribs and costal cartilage and the midaxillary line area.When the right anterior part of the trunk touched the ground,rib fracture occurred first on the side that touched the ground,and rib fractures were mainly located in the area from the right midaxillary line to the posterior axillary line,and junction of ribs on both sides and costal cartilage.When the back of the trunk touched the ground,the fracture sites were mainly located on the back of the ribs on both sides.When the right posterior part of the trunk touched the ground,multiple rib fractures were likely to occur in the parts that touched the ground.The plastic strains were mainly concentrated at the fracture sites,while the von Mises stresses were not only concentrated at the fracture sites,but also at other sites.Conclusion There are some differences in rib fracture location sites and injury mechanisms when different parts of the trunk touch the ground.