基于胡聿贤谱的带支撑广义Maxwell阻尼隔震结构随机响应分析
SEISMIC RESPONSE ANALYSIS OF GENERALIZED MAXWELL DAMPING ISOLATED STRUCTURE WITH BRACES UNDER HU YUXIAN SPECTRUM EXCITATION
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摘要: 工程中通过设置支撑将阻尼器和建筑结构连接, 但常为了简化分析, 将支撑的水平刚度看成无穷大, 即不考虑支撑对耗能结构随机地震响应的影响. 实际上, 考虑有限水平刚度的支撑对耗能结构响应的影响更加符合工程实际, 为考虑支撑影响的广义Maxwell耗能隔震结构在胡聿贤谱地震激励下的响应分析, 提出一种求解随机地震响应的简明解析解法. 将带支撑广义Maxwell阻尼器等效本构关系、隔震结构运动方程以及胡聿贤谱滤波方程联合组成非经典阻尼系统, 运用复模态法对该非经典阻尼系统解耦, 通过不同响应模态获得耗能隔震系统系列响应基于白噪声激励的Duhamel积分表达式; 利用Dirac函数的性质, 将系统系列响应协方差简化为无积分运算的表达式, 根据功率谱密度函数与其协方差函数的Wiener-Khinchin关系, 得到耗能隔震系统系列响应功率谱和地面加速度功率谱, 基于随机振动理论中谱矩的定义, 得到耗能隔震系统系列响应0 ~ 2阶谱矩. 算例通过与虚拟激励法对比分析, 验证所提方法在该耗能隔震系统分析的正确性和高效性, 并讨论了不同支撑刚度对阻尼器减震效果的影响.Abstract: The damper is connected to the building structure by setting braces in engineering, but in order to simplify the analysis, the bracing horizontal stiffness is regarded as infinite, that is, the influence of braces on the random response of energy dissipation structure is not considered. In fact, it is more in line with engineering practice to consider the effect of the braces with finite horizontal stiffness on the response of the energy dissipation isolated structure. To analyze the response of the generalized Maxwell energy dissipation isolated structure considering the influence of the braces under the Hu Yuxian spectrum seismic excitation considering the effect of the braces, a concise analytic solution for solving random seismic response is proposed. The non-classical damping system are composed of the equivalent constitutive relation of the generalized Maxwell damper with braces, the motion equation of the isolated structure and the Hu Yuxian spectral filtering equation. The complex modal method is used to decouple the non-classical damping energy dissipation isolated system, and the Duhamel integral expression of the series response of the energy dissipation isolated system based on white noise excitation are obtained through different response modes. Based on the properties of Dirac function, the energy dissipation isolated system series response covariance is simplified into non-integral expression. According to Wiener-Khinchin relationship between the power spectral density function and its covariance function, the energy dissipation isolation system series response power spectrum and ground acceleration power spectrum are obtained. Based on the definition of spectral moments in random vibration theory, the 0 ~ 2 order spectral moments of energy dissipation isolation system series response are obtained. The example verifies the correctness and efficiency of the proposed method in the bracing system by comparing with the pseudo excitation method, and discusses the influence of different bracing stiffness on damping effect of damper.