基于复阻尼理论的流固耦合地震时程响应研究

在粘滞阻尼系统的地震动力学方程基础上,建立了基于应力相关复阻尼理论的流固耦合地震动力学方程。根据复阻尼系统求解理论,利用Newmark-β积分法,编制了Rayleigh阻尼和复阻尼模型的流固耦合三维有限元程序。以深水薄壁钢管墩柱为例,计算了两种阻尼模型的流固耦合地震时程响应和复阻尼模型的损耗因子;对比分析了无水和有水两种工况下的动力响应,并研究了此两种阻尼模型地震响应的差异。研究表明,在加速度峰值为2m/s2的El-Centro波作用下,应力相关复阻尼方法计算的结构震动响应数值远大于传统的Rayleigh阻尼模型,考虑流固耦合效应时,结构的震动响应是不考虑此效应时的1.5～2倍多;损耗因子随着位移的增大而增大,并且考虑流固耦合效应时的损耗因子明显大于不考虑此效应的损耗因子值。

Study on time history of seismic response in consideration of fluid solid interaction based on complex damping theory

Based on viscous damping system dynamics equation, seismic dynamics equations of fluid-solid interaction problems with stress-related complex damping theory are established. Fluid-solid interacion 3D fem dynamic program for solving Rayleigh damping model and complex damping model structure is developed with newmark-b integration method. The seismic time history response and loss factor of a deepwater thin-walled steel pipe pier are calculated.Two kinds of response of considering fluid solid interaction effect and without regard to fluid solid effect are studied.It shows that the response with complex theory is bigger than that of Rayleigh damping theory far under El-Centro earthquake load with peak value 2m/s2. The seismic response with consideration for fluid solid interaction is half as much again to twice bigger than that without consideration for fluid solid interaction.The loss factor increases with the stress or response and the loss factor with consideration for fluid solid interation is obviously bigger than that without regard to fluid solid interaction.