层状粘弹性介质参数反演的同伦方法

以介质的动态时域位移响应作为参数反演的依据,利用大范围收敛的同伦方法对层状粘弹性介质的材料参数进行了反分析研究.动态时域位移响应比拟静态和频域位移响应含有更丰富的信息,而且在实际工程中所测得的信息也多为动态时域信号,因此将时间全过程的位移信息用于层状粘弹性介质参数反分析,将使反演的结果更合理,更接近实际.为保证迭代稳定性、削弱观测噪声的影响,同伦参数的修正采用了连续化修正方法.以三维层状粘弹性半空间介质为例进行了数值模拟,结果表明,反演结果不依赖于初始值的选取,反算过程稳定收敛,说明对反演参数连续修正的同伦反演方法对于层状粘弹性介质的动态参数反演是适用、有效的.

Inversing Physical Parameter of Stratified Viscoelastic Media by Homotopy Method

The physical parameter of stratified viscoelastic media has been inversed by the homotopy method with widely convergence from its dynamic response in time domain,which includes more information than the quasi-static movement or response in frequency domain.The movement in time domain is easy to measure,therefore,the inversion result is reasonable and pragmatic.Moreover,a continuous method is employed to modify the homotopy parameter during iteration in order to ensure the stabilization of the iteration and the capability of the noise resistance.This method is used to inverse material parameters of half-space 3-D stratified viscoelastic media.Numerical results show that the homotopy method is nearly independent of the original value,and this method is of high accuracy and validity to the dynamical viscoelastic parameter identification problems.