激光测振有限元反演优化方法测量黏弹材料动态力学参数

基于非接触式光学测振和有限元反演对黏弹材料复模量的测量进行了理论和实验研究。针对反演精度受测点选择影响显著的问题进行了误差分析,推导了灵敏度矩阵的计算公式;得到了反演误差的计算方法;找出了影响反演精度的主要误差来源;通过测点优化,提高了泊松比测试精度。利用温频等效原理,在常压、变温条件下对橡胶样品进行了温频等效测量,实验研究表明,该系统可以以较少的温度台阶获得材料主曲线,反演结果与动态机械分析仪(DMA)测试结果误差在10%以内,进一步印证了反演系统的有效性。 

A study on polymer modulus test using laser-based finite element method

The theoretical research and experiment by using laser-based FEM method to determine the complex dynamic elastic modulus of homogeneous polymer have been conducted.Errors analysis has been done according to the problem that the measurement precisions are different because of different choice of measurement points.The formula of sensitivity matrix has been deduced.The method for error bounds calculation has been obtained.The main factors which influence the measurement precisions have been find out via sensitivity analysis.A laser-based FEM inverse measurement system has been established.Measurement errors of Poisson's ratio have been significantly reduced after the optimization of measurement points.Measurement of time-temperature superposition(TTS) has been achieved by the inverse approach.The difference is within 10%in comparison with the measured date from the DMA,and this validates the accuracy of our system developed in this thesis.