铝合金板式节点受弯滞回性能试验研究

Experimental Research on Bending Hysteresis Performance of Aluminum Alloy Gusset Joints

为研究铝合金板式节点的受弯滞回性能,并与静力性能进行比较,完成了4个足尺试件的滞回加载及单调加载试验,并采用通用有限元软件ABAQUS对试验加载全过程进行数值模拟,得到了铝合金板式节点的破坏模式、弯矩-转角关系及耗能能力.采用分配梁对两杆进行对称加载,节点域为纯弯段.研究结果表明铝合金板式节点为典型半刚性节点,根据受力过程可分为弹性阶段、螺栓滑移阶段、孔壁承压阶段和破坏阶段,并得到节点弯矩-转角关系曲线.节点破坏模式为杆件净截面拉断,裂缝由杆件端头最外排螺孔处开始扩展.节点在破坏前无明显预兆,为典型脆性破坏,荷载-位移曲线没有下降段.节点滞回加载的骨架曲线与单调加载曲线接近,但滞回加载过程节点的累积损伤,导致节点延性低于单调加载.增加螺栓数量可改善节点耗能性能,使滞回曲线更加饱满.

To study the bending hysteresis performance of aluminum alloy gusset joints and compare them with static performance,four full-scale specimens were tested and subjected to hysteresis and monotonic loading,and the entire experimental loading process was numerically simulated using the general finite element software package ABAQUS.The failure mode,bending moment-rotation angle relationship,and energy dissipation capacity of aluminum alloy gusset joints were studied.Adopting the symmetrical loading method,the joint area is a pure bending segment.The research results indicate that the aluminum alloy gusset joint is a typical semi-rigid joint,and its destructive process can be divided into elastic stage,bolt slip stage,bolt and screw hole extrusion stage,and failure stage.The relationship curve of bending moment and rotation angle is obtained.The failure mode of the joint is the fracture of the member end section,and the crack begins to expand from the outermost row of screw holes at the end of the member.The joint has no obvious warning before failure and it’s a typical brittle failure,with no decreasing load.The skeleton curve of joint is similar to the monotonic loading curve,but due to the accumulated damage of the joint during the hysteresis loading process,the ductility is lower than that of monotonic loading.Increasing the number of bolts can improve the energy consumption performance of the joint and make the hysteresis loop fuller.