重力坝-地基-库水系统动态断裂分析  

DYNAMIC FRACTURE ANALYSIS OF THE GRAVITY DAM-FOUNDATION-RESERVOIR SYSTEM

作　　者：刘钧玉[1,2] 林皋[1] 胡志强[1] 

机构地区：[1]大连理工大学海洋与近海工程国家重点实验室,辽宁大连116024 [2]沈阳工业大学建筑工程学院,辽宁沈阳110178

出　　处：《工程力学》2009年第11期114-120,共7页Engineering Mechanics

基　　金：国家自然科学基金重点项目(90510018);辽宁省博士启动基金项目(20051077);教育部创新团队项目(IRT0518);沈阳工业大学博士启动基金项目(521101302)

摘　　要：应用比例边界有限元法(Scaled Boundary Finite Element Method-SBFEM)对重力坝进行动态断裂分析。通过数值算例验证了比例边界有限元法计算动应力强度因子的有效性和精度。在频域利用一种新的高阶透射边界对无限地基进行模拟,该透射边界是基于无限域动力刚度矩阵的连分式解形式,具有良好的收敛性和精度。最后对重力坝-无限地基-库水系统进行频域分析,给出了坝体最大拉应力分布和坝踵裂纹应力强度因子的时程变化规律,将最大拉应力计算结果与无裂纹情况下重力坝-地基-库水系统的结果和无质量地基模型的结果进行了对比,对比结果表明该文计算结果比无质量地基模型的计算结果降低20%―25%。Dynamic fracture analysis of gravity dam is carried out by the scaled boundary finite element method （SBFEM）. The effectiveness of the proposed approach for the evaluation of dynamic stress intensity factors is validated by the numerical benchmark examples. The influence of the unbounded foundation is modeled by a high-order transmitting boundary based on the continued-fraction solution of the dynamic-stiffness matrix, which is characterized by its good convergence and high degree of accuracy. Finally, the earthquake response of the gravity dam-reservoir-foundation is analyzed and the time history of the dynamic stress intensity factors （DSIFs） is provided. The results are compared with those of the mass-less base model and those for the case of intact dam. It is demonstrated that the dynamic stress modeled by mass-less foundation overestimates the earthquake response of the dam by 20%--25%.

关 键 词：动应力强度因子 结构-地基相互作用 比例边界有限元法 透射边界 重力坝 

分 类 号：O346.1[理学—固体力学] TV312[理学—力学]