【摘要】 按照剪切梁理论,给出了指数函数剪切模量成层土上剪切梁的自振频率方程及任意阶振型函数的解析表达式,应用振型叠加原理计算了这种梁的地震反应,然后利用随机振动理论,基于基岩输入地震加速度的功率谱密度函数、白噪声谱和过滤白噪声谱,研究了该梁对地震的随机动力响应问题。计算结果表明:在基岩输入地震加速度的功率谱为白噪声谱的情况下,土层和梁的最大期望反应均有别于过滤白噪声谱时的相应值;平稳输入与输出时,地基和梁的最大期望反应总是不小于非平稳过程时的相应值。更多还原

【Abstract】 The formulas for computing natural frequencies and modes of shear beam on the stratified foundation with exponential function shear modulus are derived according to shear beam theory.The seismic response of this kind of beam is calculated by using the mode-superposition scheme.Dynamic responses of the beam and the soil layer to earthquake are studied by the theory of random vibration.Two cases of power spectral intensity function for the earthquake acceleration input at the base rock are considered: the white noise spectrum and filter white noise spectrum.The numerical calculation results show that under the case that the power spectral density of the earthquake acceleration input at the base rock is the white noise spectrum;the maximum expected responses of the soil layer and the beam are different from that for the case of the filter white noise spectrum.Both the earthquake acceleration input the base rock and the response are stationary random process,the maximum expected responses of the soil layer and the beam are bigger than the ones with no stationary process.5 figs,7 refs.更多还原