基于修正软化拉-压杆模型的型钢#br# 混凝土深梁受剪承载力研究

为研究型钢混凝土深梁的受剪承载力，完成7组型钢混凝土深梁的静力试验和有限元分析，主要考虑剪跨比、型钢腹板高度及翼缘宽度等影响因素。试件的破坏模式为斜压破坏和剪切破坏。剪跨比对破坏形态有较大影响，较大的型钢腹板高度和翼缘宽度显著提高试件受剪承载力。在试验研究和有限元分析的基础上，考虑钢筋混凝土部分的软化效应、非软化混凝土与型钢翼缘的协调变形作用及腹板部分的受剪贡献，建立修正软化拉-压杆模型，并采用叠加原理推导型钢混凝土深梁受剪承载力实用计算方法。结果表明：修正软化拉-压杆模型能较好地反映型钢混凝土深梁的破坏特征和受力机制，文中提出的受剪承载力计算方法与试验数据吻合较好，对受剪影响因素考虑更加全面，能较好地预测型钢混凝土深梁的受剪承载力。

The study of shear capacity of steel reinforced concrete deep#br# beams based on modified softened strut-and-tie model

In order to study the shear capacity of steel reinforced concrete (SRC) deep beams, the static test and finite element analysis of 7 SRC deep beams was completed. The influence factors include shear-span ratio, section steel web height and flange width are considered. The failure modes of the specimens are diagonal compression failure and shear failure. The shear-span ratio has a great influence on the failure mode. The larger web height and flange width of section steel significantly increase the shear capacity of specimens. On the basis of experimental study and finite element analysis, the softening effect of reinforced concrete, the coordinated deformation of unsoftened concrete and flange, the shear contribution of web are considered. A modified softened strut and-tie model is established, and a calculation method for shear capacity of SRC deep beams is derived by using the superposition principle. The result shows that the modified softened strut-and-tie model can better reflect the failure characteristics and stress mechanism of SRC deep beams. The proposed calculation method of shear bearing capacity is in good agreement with the experimental data, and the factors affected by shear are considered more comprehensively. The method in this paper can well predict the shear capacity of SRC deep beams.