摘要
为了研究水平荷载下不同砂浆层厚度的平板支座节点的抗震性能及受力机理,该文利用有限元软件ABAQUS,模拟分析了8个砂浆层厚度为0 mm^50 mm的平板支座节点在单调和循环荷载下的破坏模式及承载力曲线,并将模型破坏模式及极限承载力计算值与试验结果进行对比,结果证明该模型可有效对平板支座的滞回性能进行计算分析。有限元计算结果表明,随着砂浆层厚度增加,支座节点极限承载力降低,支座锚栓由剪切变形变为弯曲变形;支座锚栓近似均匀受力;循环加载下平板支座的承载力相比于单调加载降低约30%。在有限元参数分析的基础上,综合考虑了支座锚栓的破坏机制及支座锚栓的变形对平板支座水平承载力的影响,总结平板支座的水平承载力主要由支座锚栓承担的剪力、支座锚栓轴力的水平分量及摩擦力组成,提出了平板支座节点水平承载力的计算公式。同时,在公式中引入折减系数0.7,考虑循环加载对平板支座节点水平承载力的降低。
To study the seismic behavior and stress mechanism of roof joints with mortar layers of different thicknesses under horizontal load, a parametric finite element analysis of roof joints was conducted using ABAQUS. Considering the effects of mortar thickness and loading type on the failure modes and bearing capacity curve of the roof joint, eight specimens with mortar thicknesses between 0 mm to 50 mm under either monotonic or cyclic loading were simulated. Compared with the test results, the finite element model is proved to be accurate enough for further analysis. It is noted that as the thickness of mortar layer increased, the failure mode of the anchor rods of the roof joint is changed from shear failure mode to bending failure mode. Therefore, the lateral resistance of the roof joint is reduced as the thickness of the mortar layer increases. The four anchor rods of a roof joint transfer similar amount of lateral force. The lateral resistance of the roof joint under cyclic loading is reduced by 30% compared with that under monotonic loading. Based on the analysis results, evaluation equations of the lateral resistance of roof joints were proposed which take into account the stress mechanism and the deformation of anchor rods. The lateral resistance is consisted of the shear resistance of anchor rods, the friction force between mortar layer and concrete, and the horizontal component of axial force of anchor rods. Moreover, a reduction factor of 0.7 is adopted to consider the effect of cyclic loading.
出处
《工程力学》
EI
CSCD
北大核心
2018年第2期169-179,共11页
Engineering Mechanics
基金
国家自然科学基金项目(51678106)
