流体饱和多孔介质黏弹性动力人工边界  

A VISCOUS-SPRING DYNAMICAL ARTIFICIAL BOUNDARY FOR SATURATED POROUS MEDIA

作　　者：王子辉[1] 赵成刚[1] 董亮[1] 

机构地区：[1]北京交通大学土木建筑工程学院隧道与岩土工程研究所

出　　处：《力学学报》2006年第5期605-611,共7页Chinese Journal of Theoretical and Applied Mechanics

基　　金：北京市自然科学基金重点项目(8052015)资助.~~

摘　　要：基于Biot流体饱和多孔介质本构方程,分别考察具有辐射阻尼性质的外行柱面波和球面波在圆柱面和球面人工边界上引起的法向、切向应力的表达式．在应力表达形式上,固相介质和孔隙流体的法向和切向应力都是由两项组成,它们分别与质点的位移和速度成正比,因此,可在人工边界的法向和切向设置连续分布的并联弹簧-黏滞阻尼器,用来模拟人工边界以外的无限域介质对来自有限计算域的外行波动的能量吸收作用,从而形成了流体饱和多孔介质的黏弹性动力人工边界．流体饱和多孔介质的黏弹性动力人工边界可方便地与大型通用软件结合,用于分析饱和土中复杂的结构-地基动力相互作用问题．算例表明流体饱和多孔介质黏弹性动力人工边界具有较好的精度和稳定性．In the dynamic finite element analysis of saturated porous media in whole space or half-space, a finite region is usually selected for computing, so how to deal with the boundaries of this finite region is the key procedure for simulating and analyzing the open system. Based on the constitutive equations of saturated porous media, this paper discusses the normal and tangent stress formulae on the artificial boundary of cylinder and sphere shapes under the assumption of out-going cylindrical waves and spherical waves, respectively, which attenuate with distance. With regards to the form of the formulae, the normal or tangent stress includes two terms, which are proportional to the particle displacement and velocity, respectively, so the continuously distributed parallel connecting springs and viscous damping dashpots can be placed on the artificial boundaries in the normal and tangential directions to simulate the energy absorbing function of the unbounded media outside the artificial boundaries. The viscous-spring artificial boundary can be easily applied in a large universal finite element software to analyze sophisticated dynamic problems. The examples show that the viscous-spring dynamical artificial boundaries enjoy good accuracy and good stability.

关 键 词：流体饱和多孔介质 黏弹性动力人工边界 有限元法 无限域 辐射阻尼 

分 类 号：O347.4[理学—固体力学] P315.3[理学—力学]