Calculational Unified Theory for Calculation of Shear Strength of Linear and Planar Members

在这项研究中，讨论了四个主题。主要结果如下：1)钢筋混凝土深板抗剪破坏的有效宽度由试验结果讨论了有效宽度对钢筋混凝土深板抗剪承载力的影响。加载板长度对有效宽度的影响大于支撑板长度的影响。如果认为有效宽度与荷载和支撑板之间形成的受压混凝土支撑的膨胀有关，则剪跨比是影响膨胀的一个重要因素。2)抗剪钢筋对RC板局部剪切破坏的影响试验研究了单向和悬臂板的剪切加固效果。在冲切破坏的情况下，受剪承载力随受剪钢筋的增加而提高。在梁剪切破坏的情况下，板的承载能力略有提高。在一定荷载作用下，受剪钢筋的应变开始急剧增加，但当板达到极限状态时，钢筋的应变还没有达到屈服应变。3)钢筋混凝土构件抗剪破坏中纵筋的粘结和下拉作用的建模。纵向钢筋的开裂是由销钉和粘结作用共同作用引起的。钢筋的变形可以通过将周围的混凝土建模为弹塑性弹簧来描述。裂缝的判据与钢筋的竖向位移和滑移有关。4)轴对称钢筋混凝土板的分析研究抗剪配筋对轴对称钢筋混凝土板抗剪承载力的影响可以用非线性有限元分析来描述。通过分析，阐明了拉筋和剪筋对构件刚度的影响。

In this study four topics are discussed. The major results obtained are as follows.1) Effective Width for Shear Failure of RC Deep SlabsThe effective width to the shear capacity of RC deep slabs was discussed from the experimental results. The effect of the length of loading plate on the effective width is larger than that of the supporting plate. If it is considered that the effective width is related to the swell of the compressive concrete strut formed between the loading and supporting plates, the shear span ratio is a factor of great importance to the swell.2) Effect of Shear Reinforcement on Local Shear Failure of RC SlabsFor one way and cantilever RC slabs, the shear reinforcing effects were experimentally investigated. In case of the slabs with a punching shear failure, the shear capacities increase with shear reinforcement. In case of the slabs with a beam shear failure, the capacities increase a little. The strain of the shear reinforcement starts to increase suddenly at a certain load, however, the strains do not reach its yield strain when the slabs reaches its ultimate state.3)Modeling for Dowel and Bond Actions of Longitudinal Bars in Shear Failure of RC MembersModeling for the longitudinal bars in a shear resisting mechanism was conducted. The cracking along a longitudinal bar is caused by a combined effect between the dowel and the bond actions. The deformation of the bars can be described by modeling the surrounding concrete as an elasto-plastic spring. The criteria of the cracking is related to a vertical and a slip displacements of the bars.4)Analytical Study on Axisymmetrical RC SlabsAn effect of the shear reinforcement on the shear capacity of axisymmetrical RC slabs can be described by using a nonlinear finite element analysis. The effect of the tensile and shear reinforcing bars on the member stiffness is clarified by the analysis.