含气泡弱可压缩弹性材料的等效媒质法

Effective medium method of slightly compressible elastic media permeated with air-filled bubbles

声波在含气泡弹性材料中传播时不仅使固相介质产生形变,而且会使气泡非线性振动,据此建立了含气泡弱可压缩弹性材料的等效媒质法。利用等效媒质的微单元与含气泡材料的微单元具有相同的应力和应变,求得了含气泡材料的等效Lame系数,并得到了含气泡材料的非线性波动方程。其线性化结果与Gaunaurd的经典理论相比较,有很好的一致性。本方法还可给出含气泡弱可压缩弹性材料的另一重要参数——非线性系数。

An effective medium method has been developed for the slightly compressible elastic media permeated with air-filled bubbles, according to the nonlinear oscillation of bubble, which will be happened when compressional wave travels through the porous media. The effective Lame coeificients of the porous medium and the nonlinear elastic wave equation can be deduced, as the micro-unit of effective medium should have the same stress and strain with the microunit of porous media. The linearized properties obtained by this method are in good agreement with the results of Gaunaurd＇s classic theory. Furthermore, the nonlinear coefficient, which is the important property of the porous media, can also be acquired by this method.