基于向量式有限元的黏滞阻尼减震结构抗竖向连续倒塌动力反应分析

向量式有限元是以向量力学为基础的一种新的结构分析方法,在处理结构大变形等复杂行为时具有较大的优势。基于向量式有限元理论建立了黏滞阻尼单元,对附加黏滞阻尼器的平面钢框架结构进行了抗竖向连续倒塌动力分析,结合拆除构件法,采用MATLAB编制可以考虑初始变形的瞬时卸载法程序,实现结构在构件拆除前的静力分析和构件拆除后动力分析的全过程统一。研究了阻尼器布置位置和参数在结构抗竖向连续倒塌中的性能需求,以失效点竖向位移时程曲线、梁端转角、动力放大系数和结构塑性铰分布为参考指标,对比分析布置阻尼器前后钢框架结构的抗连续倒塌能力。结果表明向量式有限元是一种研究结构竖向连续倒塌动力响应的有效方法,合理布置阻尼器能够有效控制剩余结构的变形和振动,降低构件内力,减少塑性铰个数,较大地提高结构的抗竖向连续倒塌能力。

Dynamic Response Analysis of Resisting Vertical Progressive Collapse of Frame Structures with Viscous Dampers Based on the Vector Form Intrinsic Finite Element Method

The Vector Form Intrinsic Finite Element (VFIFE) method was recently proposed for structural behavior analysis based on vector mechanics. It presents great advantages over other analytical methods, especially in the complicated behavior analysis of structures. In this work, viscous damping elements were developed based on VFIFE theory and dynamic analysis of the resisting vertical progressive collapse of a plane steel-frame structure with viscous dampers was performed. A transient unloading method program was developed to realize the unity of static and dynamic analysis before and after component removal. The performance requirements of damper arrangement and parameters during vertical progressive collapse were studied, and the progressive collapse resistance for framed structures with and without viscous dampers were compared considering the vertical displacement curves of failure point, beam-end angles, dynamic magnification factor, and the plastic hinge distribution of the structure as references. The analysis results show that VFIFE is an effective method for studying the dynamic response of vertical progressive collapse of structures and that reasonable arrangement of dampers can effectively control the deformation and vibration of structures, reduce the internal force of the components, reduce the number of plastic hinges, and greatly improve the progressive collapse resistance of structures.