两相多孔介质弹塑性动力反应计算分析

Calculation and Analysis of Elasto-plastic Dynamic Response of Fluid-saturated Porous Media

基于增量形式的流体饱和两相多孔介质弹塑性波动方程组,运用显式逐步积分格式与局部透射人工边界相结合的时域显式有限元方法对该波动方程组进行求解,对两相介质在输入地震波作用下的弹塑性动力反应进行计算和分析,从而揭示流体饱和两相多孔介质弹塑性动力反应的规律。计算结果表明:两相介质弹塑性位移反应峰值要大于相应的弹性位移反应的峰值,并且弹塑性位移反应峰值出现的时刻滞后于弹性位移反应峰值出现的时刻;两相介质弹塑性速度反应与相应的弹性速度反应的差别并不显著。数值计算同时表明,时域显式有限元方法是进行流体饱和两相多孔介质弹塑性动力反应计算分析的一种有效的方法。

In this paper, the incremental elasto-plastic wave equations of fluid -saturated porous media are solved by the time - domain explicit finite element method that consists of explicit step-by-step integral format and local transmitting artificial boundary. Then, the elasto - plastic dynamic response of fluid-saturated porous media under the action of earthquake wave input is calculated and analyzed with the method mentioned above. The calculating results show that the peak value of elasto - plastic displacement response of fluid - saturated porous media is greater than that of elastic displacement response, and the time when the peak value of elasto - plastic displacement response appears is behind that of elastic displacement response. The difference between the elasto - plastic velocity response and the elastic velocity response of fluid -saturated porous media is not significant. Meanwhile, numerical calculations indicate that the time - domain explicit finite element method is effective for the calculation and analysis of the elasto -plastic dvnamic response of fluid-saturated porous media.