新型钢节点连接PC框架子结构抗冲击行为分析

Impact-resistant behavior analysis of new steel joints connected to PC frame substructure

梁-柱连接节点是装配式结构需重点关注的部位,对整个结构的受力性能有着重要作用,一旦节点发生破坏,可引发建筑物的整体倒塌。采用新型钢节点连接的装配式混凝土(Prefabricated Concrete,PC)框架子结构,考虑钢材与混凝土材料的损伤及应变率效应,分析了其在冲击荷载作用下的动力响应及构件和连接钢节点的破坏行为,考察了冲击物冲击载荷作用面积、冲击位置、冲击动能对框架子结构动力响应及其节点连接性能的影响,并从能量角度分析了冲击荷载作用下框架子结构各构件耗能占比。结果表明:冲击荷载作用面积对钢节点的变形及混凝土损伤影响显著;冲击位置改变时,与框架梁、框架柱相比,钢节点的变形较小,且框架梁、框架柱的损伤范围发生显著的变化;动能相同时,冲击动量越大,冲击力峰值越低,作用时间越长,而动量较小时更易发生二次撞击;随着动能的增加,框架梁损伤程度增加,且损伤范围更加集中。

The beam column joint is a crucial component of a Prefabricated Concrete(PC)frame structure,which significantly affects the overall mechanical performance of the structure.Failure of the joint can result in the collapse of the entire building.The article adopts PC frame substructures with new steel joints to consider the damage and strain rate effects of steel and concrete materials.The study investigates the failure behavior of frame substructure components and connected steel joints under the impact load of an upper falling layer,as well as the effects of impact load area,impact position,and impact kinetic energy on the dynamic response and joint connection performance of the frame substructure.In addition,it also analyzes the energy consumption proportion of each component within the frame substructure under the impact load from the energy perspective.The results show that the area of impact load has a significant effect on the deformation of steel joints and concrete damage.When the impact position changes,the deformation of steel joints is smaller than that of beam and column members,and the damage range of beam and column members changes significantly.When the kinetic energy is the same,with greater impact momentum,the peak impact force is lower and the action time is longer;and when the momentum is smaller,the secondary impact is more likely to occur.With the increase of kinetic energy,the damage degree of beam members increases,and the damage range is more concentrated.