基于振动冲击响应法的生物力学等效仿真软质材料的力学性能测试与分析

Analysis of Mechanical Properties Test for Biomechanical Equivalent Artificial Soft Materials Based on Vibration and Shock Response

生物力学等效仿真软质材料力学性能的研究是研制动态仿真假人过程中的重要课题。针对软质材料硬度低、模量小和极易变形等特点,以纵向振动理论和共振原理为基础,提出了采用动态振动冲击响应试验法测试硅橡胶基软质材料的力学性能,搭建了软质材料力学性能的振动冲击测试平台,分析了对测试结果可能存在的影响因素。并对3组不同硬度的硅橡胶基圆柱形试件进行了测试,求得其固有频率和弹性模量。在试验的基础上,应用有限元软件对试件进行模态分析,提取出试件的1阶固有频率。将此参数与试验结果对比,两者误差很小,验证了所提方法的有效性和可行性。测试结果还表明软质圆柱形试件的固有频率与其长度成反比,与硬度成正比,这一结论对于软质圆柱形试件的动态分析研究有着重要的意义。

The mechanical properties of biomechanical equivalent artificial soft materials is very important to the study of dynamical experiment dummies.Based on longitudinal vibration theory and resonance principle,an experimental method was developed to measure the mechanical properties of silicon rubber soft materials according to shock response.The test platform for testing mechanical properties of soft materials was established and factors influencing test results were analyzed.Three set of specimens with different hardness were tested and the inherent frequency and elastic modulus of the specimens were obtained.On the basis of experiments,the inherent frequencies of the specimens were obtained by mode analysis using finite element analysis software.Comparing the inherent frequencies obtained by experiment and calculation showed that the error is very little,which verifies that the experimental method is correct and validated.The research results also showed that the inherent frequency of soft test bar is the inverse ratio of its length and the direct ratio of its hardness,which is important to the dynamic research and analysis of soft cylinder test bar.