弱连体结构非平稳随机地震响应与动力可靠度分析

Non-stationary random response and dynamic reliability analysis on weak connective structures

弱连体刚度小，地震作用下不能协调塔楼振动且受力不利。考虑地震动的非平稳性，运用虚拟激励法对耗能阻尼减震柔性连接与非减震刚性连接的弱连体结构在非平稳随机激励下的地震响应进行研究。采用Bouc—Wen模型与刚度退化的Bouc—Wen模型分别模拟连体滞变特性与塔楼各楼层的滞变特性，建立弱连体结构非线性化动力方程。运用混合精细积分法对每一时刻的响应进行求解，得到弱连体结构在非平稳随机激励下的位移、速度时变方差。基于首次超越破坏准则，研究非平稳随机地震激励下弱连体结构的塔楼与连体的动力可靠度。运用上述理论，分析某高层双塔连体结构在8度（0．2g）多遇、罕遇地震作用下的随机地震响应。研究结果表明，高层双塔连体结构的层间位移响应呈现强烈的非平稳性，地震作用下耗能阻尼减震柔性连接对提高连体结构的动力可靠度效果明显，表明耗能阻尼减震连体方案为弱连体结构设计推荐方案。

The weak connector with small stiffness cannot coordinate the vibration of tower and its force is unfavorable under the seismic action. Considering the non-stationary characteristics of the earthquake ground motion, the random seismic response of the damping and non-damping weak connective structure was investigated using pseudo excitation method. The Bouc-Wen model and the stiffness degradation of Boue-Wen model were used to simulate the hysteresis of the connector of the damper structure and the tower structure respectively, and the nonlinear motion equation of the weak connective structure was established. And the system response for each moment was solved by mixed precise integration method to obtain the time-history variances of displacement and velocity of the structure under non-stationary earthquake excitation. Based on the first passage damage criterion, the reliability index of towers and connector of the weak connective structure were calculated. Those theories were used to analyze random earthquake response of a high-rise double-tower linked with weak connective structure under 8 degree （0. 2g） frequent and rare earthquakes. The research results show that the high-rise twin towers connective structure＇s interlayer displacement responses have a strong non- stationary feature, and the damping weak connective form has a significantly effect on improving the structural dynamic reliability under the frequent and rare earthquakes, which proves that the energy dissipation damping weak connective structure is a recommended scheme for weak connective structures.