考虑初始静力荷载效应的框架结构部分底层柱失效时的瞬时动力分析

Instantaneous dynamic analysis of frame structure at the moment of ground column failure with consideration of static load effect

为研究高层建筑结构整体性问题中连续倒塌问题,采用有限元方法模拟高层结构底层边柱突然失效时的瞬时动力响应。从计算结果可以看出,动力分析的水平位移比静力作用的最大水平位移大很多并以静力位移为中心上下波动,并在阻尼作用下收敛到静力位移。初始静力荷载效应使瞬时动力响应的振幅比无初始静力荷载效应的结构的水平和竖向位移振幅小。初始静力效应对结构瞬态响应的影响与刚度、质量、阻尼等因素有关,刚度越小,质量、阻尼越大时,初始静力荷载效应对结构最大位移影响越小。在对底层边柱突然失效的高层结构进行分析时,必须计算结构的瞬时动力响应。建议以较为简单的无初始静力荷载效应时的瞬时动力响应作为结构设计依据,其结果趋于安全。

The finite element method is used to simulate the instantaneous response of a high-rise building with a sudden invalidation of side columns of the ground floor. Conclusions can be drawn from the calculation results that the instantaneous horizontal displacement of the structure fluctuates around the static result and converge to the static displacement because of the influence of damp. The biggest displacement of the instantaneous response is much bigger than that of the static one. The effect of initial static load on the instantaneous response makes the amplitude of vibration of horizontal and vertical displacement bigger than that without the effect. The effect of initial static load on the instantaneous response is related to the stiffness, mass and damp. The smaller the stiffness and the bigger the mass and the damp is, the smaller the effect of static load on the maximum displacement is.