柔性头颅模型撞击弹性板的动态响应分析

将柔性接触撞击过程处理为一个振动系统响应,采用机械网络图和求机械阻抗的方法解决了这一动态响应问题。柔性接触撞击模型考虑了头部的实际结构,把头部简化成撞击部位的头皮和头骨的质量、头部其它部分的头骨和脑液的质量、头部的刚度、头皮和脑液的阻尼系数组成的振动模型,弹性板也同样简化成由质量、刚度和阻尼构成的振动模型。采用求激振点速度阻抗的方法,得到了系统的动态撞击力、头部所受到的撞击加速度值,以及板的弹性变形、系统的固有频率等动态响应。实验数据与计算数据符合较好,证明方法是计算撞击作用下系统动态响应的实用方法,从而为头部撞击保护设计提供参考。

Method of Model Analysis for Flexible Head Impacting With Elastic Plane

The process of head impacting with elastic plane was modeled as a response of vibrant system, and the method of mechanical network figure and mechanical impedance was used to resolve this problem.Based on its structure, head was viewed as a vibrant model, which concludes the masses of scalp and bone in the impact area, the masses in the other part of the head and the brain, the stiffness of the head, and the damper of the scalp and brain.Also the elastic plane was simplified as a vibrant model including mass, stiffness and damper.The models were transformed into mechanical girding figure at violent vibration poin.When the initial impact speed is known, the impact force of the system,the impact acceleration of the head, the elastic deformation of the plane and the fixed frequency of the system can be worked out by calculating the velocity impedance at the violent vibration point, the results fit the test data well, which proves that this method is available for the analysis of the dynamic response of the system under impact.