土工结构物渐进破坏过程Cosserat连续体有限元分析  

Finite element analysis of progressive failure process in geotechnical engineering structures based on Cosserat continuum

作　　者：唐洪祥[1,2] 李锡夔[3] 

机构地区：[1]大连理工大学海岸和近海工程国家重点实验室,辽宁大连116024 [2]大连理工大学土木工程学院,辽宁大连116024 [3]大连理工大学工程力学系,辽宁大连116024

出　　处：《大连理工大学学报》2010年第3期320-327,共8页Journal of Dalian University of Technology

基　　金：国家自然科学基金资助项目(50808033;90715011);辽宁省教育厅科技研究资助项目(2008Z055)

摘　　要：基于压力相关弹塑性Cosserat连续体模型的有限元过程,有效地模拟了挡土墙、开挖边坡等岩土工程结构中由土体剪胀(非关联塑性流动)或应变软化行为所引起以应变局部化为特征的渐进破坏现象.挡土墙中的土体考虑为非关联的理想弹塑性材料,而边坡开挖中的土体为应变软化弹塑性材料.数值结果表明,基于经典连续体的有限元分析不能完成整个破坏过程的模拟,而所发展的基于Cosserat连续体模型的有限元过程具备保持由非关联塑性或应变软化引起的应变局部化边界值问题的适定性和模拟土工结构物中整个渐进破坏过程的能力.Based on the finite element procedure of proposed pressure-dependent elastoplastic Cosserat continuum model,progressive failure phenomena occurring in typical geotechnical engineering problems such as the retaining wall and the excavation slope,characterized by strain localization due to the material dilatancy （non-associated plasticity） or strain softening,are numerically simulated. The non-associated perfect elastoplastic behavior is particularly considered for the retaining wall and the strain softening behavior for the excavation material. Numerical results validate the inability of classical continuum model in simulating the whole failure progress,while the capability and performance of Cosserat continuum model in keeping the well-posedness of the boundary value problems characterized by the strain localization with strain softening behavior or non-associated perfect elastoplastic behavior incorporated and in simulating the entire progressive failure process occurring in geotechnical engineering structure.

关 键 词：Cosserat连续体模型 应变软化 剪胀 非关联塑性 应变局部化 

分 类 号：TB115[理学—数学]