基于数字手臂的冲击力扩散机制建模与分析

Modeling and analysis of the diffusion mechanism of impact force on digital forearm

目的:分析在爆炸冲击与侧向瞬时倾倒时,人体手臂内部的损伤效应。方法:以中国数字人中肩部到指尖的727张影像数据作为数据基础,经过组织分割、三维建模以及逆抄数的方式获得组织结构几何实体,在COMSOL Multiphysics 5.5有限元仿真软件中建立人体前臂损伤机制模型,通过在载荷面加载1.4×10^(6)N/m^(2)的冲击力,响应时间2×10^(-5)s,以此分析前臂受到应力时的冲击力扩散机制。结果:通过建模分析发现,由于皮肤、脂肪、肌肉是粘弹性组织,当机体受到应力冲击时,应力会通过变形的方式将能量释放出来,在应力冲击下这些组织损伤并不明显。然而,由于骨骼是刚性组织,外界施加的能量在此处没法转化成位移消散,从而导致在骨骼处会有大量能量蓄积,骨骼处的应力张量最大。当应力张量超过骨骼最大承受值时,就会引起骨折来进行能量转移。结论:在应力冲击中,由于粘弹性组织可以将应力能量转化成位移来实现能量消散,而刚性组织无法实现,从而导致在应力冲击中,骨骼的损伤是非常明显的。

Objective To analyze the damage effect inside human arm when suffering from explosion impact and lateral instantaneous toppling.Methods Taking the 727 images from the shoulder to the fingertip of the Chinese Digital Human as the data basis,the geometric entity of the tissues was obtained through tissue segmentation,3D modeling,and reverse engineering.Subsequently,the injury mechanism model of stress on human forearm was established using the finite element simulation software COMSOL Multiphysics 5.5.The diffusion mechanism of impact force on human forearm was analyzed by loading the impact force of 1.4×10^(6)N/m^(2) on the surface,with the response time of 2×10^(-5)s.Results Through modeling and analysis,it was found that because of the viscoelastic properties of skin,fat and muscle,when the body was subjected to stress impact,the generated energy could be released by deformation,so that the body would not be seriously damaged,and that the damage of stress impact to these tissues was not obvious.However,the bone is a kind of rigid tissue,and the energy exerted externally could not be converted into displacement and dissipated here,which caused a large amount of energy accumulated at the bone,so that the stress tensor at the bone was the largest.When the stress tensor exceeded the maximum bearing value of the bone,it would lead to fractures for energy transfer.Conclusion Under stress impact,the viscoelastic tissue can convert stress energy into displacement for energy dissipation,while rigid tissue cannot.Therefore,the damage of stress impact to the bone is very obvious.