冲击荷载下梁端削弱型钢框架的动力分析

Dynamic analysis on steel frame with reduced beam section under impact load

美国1994年北岭地震和日本1995年阪神地震之后,国内外学者对一种钢框架新型削弱型延性节点进行了大量的试验和数值分析研究,证明能将地震作用下结构的塑性铰发生位置由原来的梁柱连接处转移到距离柱截面一定距离处,大大提高结构的抗震能力。本文利用ANSYS/LS-DYNA有限元分析软件对未经削弱和削弱之后的钢框架在冲击荷载下的响应进行分析和校核,得到冲击荷载作用下能量在梁柱间的分配情况、结构的刚度变化情况和相应应力分布,并研究了削弱深度对钢框架的影响,同时针对数值分析结果提出几点改造建议。

After the 1994 Northridge and the 1995 Kobe earthquakes, great investigations and analyses had been carried on a new shaved ductile connection which can transfer the plastic hinge from the interface of beam and column to a certain position in the beam and survive steel structures in huge earthquakes. In this paper,with ANSYS/LS-DYNA software,a discrimination of allocation of energy in beam and column,rigidity and its stress distribution of the frame under impact load are given, together with the effect of the depth of reduced connection to the frame, arriving at a satisfied shock resistance result, which is followed by some adviees for the vulnerable segments.