在多点激励地震反应分析中,传统的随机振动分析方法存在数值积分耗时太长的问题。为了克服这一缺点,ANSYS通过对输入功率谱采用对数形式的分段线性表示,然后采用解析解积分方式进行随机振动求解,计算效率精确高效。采用该方法对一高位隔震多塔连体结构进行双向水平地震动作用下多点激励随机地震响应分析,并对空间变化地震动作用下连廊桁架杆件内力响应极大值的均值进行比较分析。分析结果表明:在水平双向地震动作用下,考虑行波效应和部分相干效应会使连廊杆件轴力有所增大,在设计时应引起重视。
Traditional random vibration method requires a large number of numerical integrations,which is very time-consuming in multi-excitation analysis.Based on closed-form integration for polynomial-type power spectral density functions in log-log scales,a robust integration technique which has been applied in ANSYS can overcome these drawbacks and has been verified to be efficient and accurate.The stochastic responses of corridors of connected high-rise structures under multi-support excitations of bilateral horizontal seismic action are numerically simulated by the technique in this paper.The mean of maximum and variance response values obtained from the spatially varying earthquake ground motions are compared.The results show that the axial forces of the bars of the corridors have been increased when considering the wave-passage and the partial coherence,so the spatially varying earthquake ground motions should be considered in the analysis.