回顾并比较了地震动激励下计算结构响应的位移输入模型和一致加速度输入模型,详细地讨论了由于阻尼项忽略不同导致两种输入模型的本质差别,分析了由此对计算结果产生的影响,并通过数值算例说明该影响不容忽视,进而建议在比较地震动多点激励与一致激励下的结构反应时,一致激励应采用位移输入模型而不是一致加速度输入模型,从而可避免由于两种模型本身阻尼项忽略不同对计算结果产生的影响。此外,指出了振型叠加方法在严格理论上不适用于位移输入模型。
Two types of models, displacement input model and uniform acceleration input model, for structural response calculation subjected to earthquake ground motions, are reviewed and discussed. It is found that the omitted damping terms in the two models are different, which may have significant influence on structural responses. It is recommended that displacement input model, rather than uniform acceleration input model, to be adopted in comparing seismic responses caused by consistent excitations with those Caused by multi-support excitations, to avoid the influence of the difference in omitted damping terms. Moreover, it is pointed out, contrary to the current viewpoints, modal superposition method is not applicable to the displacement input model.