【摘要】 将集总参数模型与时域差分递归的滤波器模型相结合,提出了一种可完整考虑基础阻抗函数中奇异项和正则项且精度可控的时域地基阻抗力的计算方法,数值算例表明该方法在感兴趣的频域范围内对频率相关的阻抗函数拟合良好.更多还原

【Abstract】 Interaction forces between foundation and structure is one of key problems in nonlinear dynamic response analysis of structures accounting for soil-structure dynamic interaction. Currently there are two kinds of methods dealing with it: one is the direct integrity analysis approach, and the other is time-domain substructure approach. Because of far less computational cost comparison to the former, the time-domain substructure approach is very important in engineering. The fact that foundation impedance complexly varies with frequency makes the calculation of time-domain foundation resisting force time-consuming. To simplify the calculation of the time-domain foundation resisting force, many lumped-parameter models have been proposed. Lumped-parameter model reflects the singular component of foundation impedance which is not square integrable and corresponds to simultaneous effect. Nevertheless the regular component can not be reflected accurately, which corresponds to time-delay effect and can be square integrable. The time-domain recursive model proposed by Safak (2006), used for representing the time-domain foundation resisting force, can simulate the regular component of foundation impedance. But the whole essential of foundation impedance can not be reflected in this model because the corresponding filter function has intrinsically limitation at Nyquist frequency. Thus, the time-domain foundation resisting force can not be simulated accurately. Combining the lumped-parameter model and the time-domain difference recursive filter model, a time-domain difference approach of accuracy controllable foundation resisting force is proposed. Numerical results demonstrate that the proposed procedure can perfectly fit the frequency dependent impedance in an interested frequency band.更多还原