内置角钢改进夹心节点抗震性能研究与抗剪承载力计算

梁柱采用不同强度混凝土的节点核心区通常采用同柱等强的高强度混凝土浇筑（传统节点），而采用同梁等强的低强度混凝土浇筑（夹心节点）可简化施工过程，但同时降低了节点的抗震性能。为研究内置角钢改进夹心节点的可行性，通过一个空间夹心节点和一个内置角钢空间夹心节点试件进行双向等幅低周往复试验研究，对比分析了破坏模式、延性、耗能、刚度、应变和抗剪承载力等方面的差异。结果表明：采取改进和不采取改进措施节点破坏模式均以梁端屈服后的节点破坏为主，但采取改进措施的试件延性和抗剪承载力明显提高，耗能能力、刚度退化和变形能力有一定改善，表明改进措施改善了节点的抗震性能。最后在此基础上，给出了与该文和其他文献试验结果吻合较好的采取或者不采取改进措施夹心节点抗剪承载力计算公式。

SEISMIC PERFORMANCE OF 3D SANDWICH JOINT WITH IMPROVEMENT MEASURES AND SHEAR STRENGTH CALCULATION

The joint core area is always casted with higher strength concrete of column.The sandwich beam-column joints core area casted with weaker strength concrete of beam can simplify the construction process,but the seismic performance of the joint is impaired.To study the feasibility of the sandwich joint improved with built-in angle iron,one unimproved and one improved 3D sandwich joints were tested under bi-directional reversed cyclic loads with constant amplitude to investigate the seismic behavior,including the failure mode,ductility,energy dissipation,stiffness,strain and shear strength.The test results show that,two specimens exhibit joint failure after the beam longitudinal reinforcement yields in the joint under bi-directional loads.However,the enhancement measure increases ductility and shear strength,improves energy dissipation,stiffness declination and deformation capacity,which indicates that the seismic performance of sandwich joint is improved.Finally,the formula is presented for calculating shear strength of the sandwich joints,and the solutions agree well with the experimental results of unimproved and improved sandwich joints.