复合承载型自复位梁柱节点有限元研究

FINITE ELEMENT ANALYSIS OF COMPOSITE LOAD-BEARING SELF-RESETTING BEAM-COLUMN JOINTS

基于损伤控制思想,提出一种复合承载型自复位梁柱节点,该节点通过高强预应力钢索为结构提供预拉力,使结构在地震作用下可以实现自复位,通过震后更换设置在节点上的狗骨削弱盖板,可实现结构震后可修复。利用有限元软件对5个节点模型进行有限元模拟,通过改变高强预应力拉索的初始索力和狗骨削弱盖板的厚度来研究两者对节点承载能力、耗能能力、自复位能力和震后修复能力的影响,获得了5组模型的荷载-位移曲线、索力变化曲线以及应力分布形态。研究表明:在保证模型实现自复位的前提下,无狗骨削弱盖板的构件塑性损伤较严重,带狗骨削弱盖板的构件可以有效降低节点主体构件的塑性损伤,增加狗骨削弱盖板的厚度和提高索力均可提高节点模型的承载能力和耗能能力,但增加狗骨削弱盖板厚度的作用更明显。

Based on the idea of damage control,a composite load-bearing self-resetting beam-column joint was proposed,which provided pretension for the structure through high-strength prestressed steel cables so that the structure could realize self-resetting subjected to earthquake action.The dog-bone weakened cover plate installed on the joint could be replaced after earthquake so that the structure was repaired.The finite element simulation for five joint models was conducted.By changing initial cable forces of high-strength prestressed cables and the thickness of dog-bone weakened cover plates,the influences of the two on the bearing capacity,energy dissipation capacity,self-resetting capacity and repairability after earthquake of the joints were studied,and the load-displacement curves,cable force change curves and stress distribution forms of the five models were obtained.The research showed based on the premise of ensuring the self-resetting of the model,the plastic damage without dog-bone weakened cover plates was more serious.The specimens with dog-bone weakening cover plates could effectively reduce the plastic damage of the main elements of the joints.Increasing the thickness of dog-bone weakening cover plates and cable forces could both improve the bearing capacity and energy consumption capacity of joints,but increasing the thickness of dog-bone weakening cover plates was more obvious.