框桁式复合墙体抗震性能试验及有限元分析

提出一种新型框桁式复合墙,由钢筋混凝土外框和内部桁式杆件构成。为了研究其抗震性能,按1∶2的缩尺比例初步设计和制作了3个单片框桁式复合墙体,进行了拟静力试验,并采用ABAQUS软件建立了有限元非线性分析模型,重点分析了轴压比、混凝土强度、箍筋配箍率及纵筋配筋率对其承载力和延性的影响。结果表明,墙体桁杆先于外框墙肢产生变形和破坏,最终在墙肢底部与桁杆围成的三角形部位由于弯矩值达到极限而发生破坏,破坏顺序明确,可达到多级耗能的目的;三个试件的延性系数均小于2.5,各试件延性系数的不同说明桁杆截面形式是影响墙体承载力的重要因素;随着轴压比、混凝土强度和纵筋配筋率的增大,试件承载力有不同程度的提高,试件的延性系数随轴压比和纵筋配筋率的增大而减小,随混凝土强度的增大而增大;箍筋配箍率对试件荷载-位移曲线、承载力和延性系数的影响很小;各因素对各项抗震性能的影响程度不同。

Seismic performance test and finite element analysis of frame truss composite wall

A new type of frame-truss composite walls composed of reinforced concrete frames and internal truss members is proposed in this paper.In order to study the seismic performance,3 units of frame truss composite walls according to the reduced scale of 1:2 were preliminarily designed and manufactured,a pseudo-static test was carried out,and a nonlinear finite element analysis model was established by using ABAQUS software.The influence of bearing capacity and ductility by the axial compression ratio,concrete strength,stirrup ratio and longitudinal reinforcement ratio was analyzed.The results show that the truss was deformed and destroyed prior to the outer wall,and finally ultimate destruction occured at the location of the triangle formed the bottom of the wall and the truss when the bending moment reaches the limit capacity,the sequence of damage is clear.The purpose of multistage energy dissipation can be achieved.The ductility coefficient of three specimens were less than 2.5,the difference of ductility coefficient between three specimens shows that the shape of the truss cross section is an important factor affecting the bearing capacity of the wall.With the increase of axial compression ratio,concrete strength and longitudinal reinforcement ratio,the bearing capacity of specimens increases to different degrees,the ductility coefficient of specimens decreases with the increase of axial compression ratio and longitudinal reinforcement ratio,but increases with the increase of concrete strength.In addition,the effect of reinforcement ratio on load-displacement curve,bearing capacity and ductility coefficient of concrete is very minor;each factor has different influence on the seismic performance.