隔震结构实振型分解反应谱法的计算精度分析及改进

Analysis of calculation accuracy and improvement of real mode superposition response spectrum method of isolated structures

由于隔震结构具有典型的非比例阻尼特性,若采用实振型分解反应谱法,计算结果会有较大误差,但实振型分解反应谱法计算简单,工程人员较易掌握。因此,分析了影响隔震结构实振型分解反应谱法计算精度的几个因素,包括隔震层等效线性化参数、阻尼参数计算和设计反应谱。通过对这三个因素的分析,针对隔震结构提出了具有较高计算精度的实振型分解反应谱法。工程实例表明,采用改进后的实振型分解反应谱法与时程分析结果相比,误差在5%左右,可满足工程设计的要求。

Because the isolated structure has typical non-proportional damping characteristic,using the real mode superposition response spectrum method to analyze structure will cause large calculation error,but the method is simple,which is easy for engineers to grasp.Therefore,several factors influencing the calculation accuracy of the real mode superposition response spectrum method of the isolated structure were analyzed,including the equivalent linearization parameters of the isolation layer,the calculation of damping parameters and the design response spectrum.Through the analysis of three factors,the real mode superposition response spectrum method with high computational accuracy was proposed for the isolated structure.The engineering examples show that,compared with the time history analysis method,the error for the calculated results of the improved real mode superposition response spectrum method is about 5%,which can satisfy the requirements of engineering design.