【摘要】 对于大型结构地震响应分析,结构-无限地基耦合系统动力分析的数值实现,往往由于有限元网格过多,以及地基无限域时域计算模型中存在的复杂卷积运算,严重限制了求解规模.为解决此问题,提出了基于阻尼溶剂抽取法的三维结构-地基相互作用分析的分区时域逐步求解模型.并针对三维大规模工程问题的数值求解,在积分算法及矩阵存储格式等方面,结合阻尼溶剂抽取法的特点进行了详细的探讨,以推进动力相互作用时域数值分析的实用化.以三维全空间球形空腔动力变形及大岗山拱坝的地震响应分析为例,针对上述数值实现算法进行了具体验证,并就不同的地基弹模及地震波输入方式对坝体响应的影响进行了探讨.计算结果表明,地基辐射阻尼以及河谷散射效应对结构的动力响应有很大影响,而该模型表现出了良好的精度和计算效率.更多还原

【Abstract】 The dynamic analysis of structure-unbounded foundation system in the time domain often involves excessive finite elements and convolution integrals,and they severely limit the application to large 3-D engineering problems.A sub-regional progressive algorithm for 3-D problems is presented on the basis of the damping solvent extraction method.What′s more,some research work was done on the integral arithmetic and storage style of matrices such that convolutional integrals can be fully avoided,the discretization of the system′s equations of motion can be simplified and the computation capacity can be expanded.A spherical cavity embedded in full-space under radial even load and the Dagangshan Arch Dam under seismic load were analyzed as verification.In addition,the influence of elastic modulus and input mode of the seismic wave on the response of the dam was discussed.It′s shown that the radiation damping of unbounded foundation and scattering effect of the river valley have great influence on the response of structure.In the meantime,the algorithm proposed exhibits good accuracy and efficiency.更多还原