摘要
在地下结构地震响应的简化分析模型中,无限地基的辐射阻尼通常以附加阻尼罐的形式与结构动力刚度阵耦合在一起,其阻尼形式不同于结构阻尼或比例阻尼.由于复杂地质条件以及计算规模的限制,采用理论或数值分析方法得到的无限地基辐射阻尼参数与实际情况往往有较大的差别.引入节点阻尼,并提出利用复特征对进行参数识别的思想.同时为了解决由于阻尼阵与刚度阵的耦合而产生的非线性问题,构造了一种迭代算法.结果表明,算法能够比较准确地识别各类参数.
The radiation damping induced by an infinite medium has great effects on the dynamic response of underground structures,which is usually added on the nodes at the outer boundary of the structures in a simplified model.The mechanics of radiation damping is different from the structural damping and is difficult to obtain because of the complexity of geological and geographical conditions and the limit of computational size.In this paper,the complex modes are used to obtain the parameters of this kind of structure and an iterative algorithm is proposed in solving the coupling of damping and stiffness.Finally,a numerical example is applied and the results show that the parameters including node damping can be estimated accurately.
引文
[1]李杰,陈隽.部分输入未知时求解动力复合反演问题的补偿算法[J].计算力学学报,2002,19(3):310-314.
[2]李杰,陈隽.结构参数未知条件下的地震动反演研究[J].地震工程与工程振动,1999,17(3):27-32.
[3]陈隽,李杰.系统非线性参数识别的松驰法[J].振动工程学报,2001,14(4):447-450.
[4]魏来生.结构有限元动态模型修正方法综述[J].振动与冲击,1998,17(3):43-46.
[5]冯新,周晶,陈健云.基于观测柔度阵的参数识别[J].世界地震工程,2002,18(1):51-55.
[6]杨杰,耿遵敏,谭雪琴.基于复模态的结构有限元动态模型修正理论[J].振动与冲击,2002,21(1):30-32.