框桁式墙体抗震性能试验及影响因素研究

Test of seismic performance of frame truss wall and influencing factors

为研究新型框桁式墙体抗震能力,设计4片框桁式墙体试件进行拟静力试验,对比分析了墙体试件的破坏形态、滞回曲线、承载力、延性及性能特征点。并应用ABAQUS软件建立墙体的非线性数值模型,考虑了轴压比、混凝土强度、配箍率和配筋率等因素的影响,计算得到了荷载-位移曲线,分析了承载力及延性变化特征。结果表明:各墙体试件破坏过程为,内部桁杆先于外框墙肢发生变形并耗能,而后桁杆与外墙肢的底部相交处形成塑性区并破坏;在桁式杆件中配置角钢、增大混凝土强度、配箍率和纵筋配筋率也可提高试件延性,而配置角钢时,配筋率对承载力的影响不明显,混凝土强度较高时,其延性不再明显提高;增大轴压比可提高试件的承载力,但会使试件的延性降低。研究结果可为框桁式墙体抗震设计提供依据。

Four specimens of the new frame truss wall were designed to study the seismic performance using cyclic loading test.The failure modes,hysteretic curves,bearing capacity,ductility and performance characteristics of four specimens were compared and analyzed.The nonlinear numerical model of the wall was established by using ABAQUS software.The loading displacement curve,the bearing capacity and ductility were compared by considering the influence of axial compression ratio,concrete strength,stirrup ratio and reinforcement ratio.The results indicated regarding the failure process of each wall,the interior truss element had deformation and energy dissipation prior to the exterior frame wall,and then the truss wall formed a plastic zone and failed at the intersection with the bottom of the exterior wall.The ductility of the specimen can also be improved by built-in angle steel in truss member,thus increasing concrete strength,stirrup ratio and longitudinal reinforcement ratio,while the effect of reinforcement ratio on the bearing capacity is not obvious in the case of built-in angle steel.The ductility is no longer significantly improved when the concrete strength is increased.The bearing capacity of the specimen is enhanced with the increase of the axial compression ratio while the ductility is reduced.The research results can provide a fundamental basis for the seismic design of the frame truss wall.