沙漠砂混凝土梁柱空间中节点抗震性能有限元分析

Seismic behavior of finite element analysis for desert sand concrete beam-column space joint

为得到沙漠砂混凝土梁柱空间中节点的抗震性能,利用ABAQUS软件建立7个沙漠砂混凝土和1个普通混凝土空间中节点有限元模型,通过得到的结构破坏现象、滞回曲线、骨架曲线、延性性能等研究了混凝土材料、加载制度,轴压比及配箍率等对梁柱空间中节点抗震性能的影响。结果表明:沙漠砂混凝土与普通砂混凝土节点的屈服荷载、极限载荷、屈服点至极限点承载力余量、初始刚度与延性系数相近,且屈服点至极限点变形能力储备比普通砂混凝土节点约大23%;双轴加载与单轴加载空间节点的平均屈服荷载、平均极限荷载和屈服点至极限点承载力余量相近,而屈服点至极限点变形能力储备比单轴加载空间节点小约13%;随着轴压比从0增加至0.6,试件的屈服荷载逐渐增大,屈服点至极限点承载力余量逐渐减小;随着配筋率从1.54%增加至3.08%,试件的屈服荷载和极限荷载逐渐增大,屈服点至极限点承载力余量逐渐减小;沙漠砂混凝土空间节点的破坏位置位于梁柱交界处柱子的四角,钢筋的屈服位置位于节点的柱纵筋处。

In order to obtain the seismic performance of desert sand concrete space middle joints,the finite element models of seven desert sand concrete and one common concrete joint are established by ABAQUS software.The influence of concrete material,loading system,axial compression ratio and stirrup ratio on the seismic performance of joints is studied through the obtained structural failure phenomenon,hysteretic curve,skeleton curve and ductility performance.The results show that The yield load,ultimate load,residual bearing capacity from yield point to ultimate point,initial stiffness and ductility coefficient of desert sand concrete joint and common sand concrete joint are similar,but the deformation capacity reserve from yield point to ultimate point is about 23%larger than that of common sand concrete joint.The average yield load,average ultimate load and yield point to limit point bearing capacity margin of biaxial loading and uniaxial loading spatial nodes are similar,but the deformation capacity reserve of yield point to limit point is about 13%less than that of uniaxial loading spatial nodes.With the increase of axial compression ratio from 0 to 0.6,the yield load of the specimen increases gradually,and the bearing capacity margin from the yield point to the ultimate point decreases gradually.The failure position of the spatial joint of sand concrete is located at the four corners of the column at the junction of the beam and column,and the fracture position of the rebar is located at the longitudinal bar of the column at the joint.