有缝重力坝动力非线性数值计算模型及其应用
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摘要
对于有缝重力坝的分析,基于连续介质力学的界面单元-有限元方法难于比较精确地模拟缝间的接触应力,从而无法合理地估算坝体应力与变形。作者对于多体系统和分区连续介质所发展的非连续变形计算力学模型能够根据接触界面的本构特性及其力学和运动学约束条件精确地再现受力过程中界面相互作用力的传递与非连续变形状态,本文将其应用于有缝重力坝的动力分析。实例数值分析表明该模型的计算结果从定性上讲是合理的,并且为判断坝体缝隙的工作状态与界面应力提供了有力的依据。
The interface elements such as joint elements are widely used in common practice to analyze the stresses and deformations of a concrete gravity dam with joints. However such models cannot authentically simulate the actual dynamic behavior of joints and interface between different media subjected to earthquake-induced irregular loading. In this paper, the new mechanical model together with mathematical formulations for analyzing discontinuous deformation system developed by the authors in recent years is briefly presented. It is based on the generalized finite elements and contact-force elements. In this method, both the yielding conditions on stresses in continuous media and interaction forces along the discontinuous interface and deformation constraints on the sliding and debonding of interface are taken into consideration. Then this method is applied to dynamic analyses of nonlinear seismic responses of the concrete gravity dam with joints to earthquake shaking. Numerical computations for a practical dam as an illustrative example are performed and meaningful results associated with the normal and shear stresses along the interfaces and along the dam-foundation interface are presented together with the stresses and deformations of dam. It has been shown that the computational results of the model are reasonable. Thus it is shown that the discontinuous deformation mechanics model is not only suited to static analyses, but also can be adapted to dynamic simulations of nonlinear behavior of multi-body with material surfaces and joints. The model can predict stresses and deformations of the continuous media and as well as the interaction forces and displacements of contact surfaces.
The interface elements such as joint elements are widely used in common practice to analyze the stresses and deformations of a concrete gravity dam with joints. However such models cannot authentically simulate the actual dynamic behavior of joints and interface between different media subjected to earthquake-induced irregular loading. In this paper, the new mechanical model together with mathematical formulations for analyzing discontinuous deformation system developed by the authors in recent years is briefly presented. It is based on the generalized finite elements and contact-force elements. In this method, both the yielding conditions on stresses in continuous media and interaction forces along the discontinuous interface and deformation constraints on the sliding and debonding of interface are taken into consideration. Then this method is applied to dynamic analyses of nonlinear seismic responses of the concrete gravity dam with joints to earthquake shaking. Numerical computations for a practical dam as an illustrative example are performed and meaningful results associated with the normal and shear stresses along the interfaces and along the dam-foundation interface are presented together with the stresses and deformations of dam. It has been shown that the computational results of the model are reasonable. Thus it is shown that the discontinuous deformation mechanics model is not only suited to static analyses, but also can be adapted to dynamic simulations of nonlinear behavior of multi-body with material surfaces and joints. The model can predict stresses and deformations of the continuous media and as well as the interaction forces and displacements of contact surfaces.
引文
[1] 迟世春,胡志强,林皋.有缝重力坝静动力特性研究[A].第五届全国地震工程学术会议论文[C].北京,1998.
[2] 黎勇,栾茂田.非连续变形计算力学模型的基本原理及其线性规划解[J].大连理工大学学报,2000,40(3):352-360.
[3] 栾茂田,黎勇.多体非连续变形系统的计算力学模型及其应用.待发表.
[2] 黎勇,栾茂田.非连续变形计算力学模型的基本原理及其线性规划解[J].大连理工大学学报,2000,40(3):352-360.
[3] 栾茂田,黎勇.多体非连续变形系统的计算力学模型及其应用.待发表.
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