Shear in Reinforced Concrete

剪力作用是钢筋混凝土结构破坏的重要因素。一个软化桁架模型理论已经发展，能够预测各种类型的结构的行为，当剪切是主要的。第一个目标是推广软化桁架模型理论，使其可以应用于剪切（扭转）与轴向载荷相结合的情况。第二个目标是对40人进行测试。钢筋混凝土板尺寸的确定需要一般理论中的材料规律，包括软化规律、裂缝本构规律和混凝土的支配贡献规律。这项研究将在一个44万美元的小组中进行。最近在休斯顿大学完成的测试设施。这个设施由一个巨大的钢框架组成，里面嵌入了40个千斤顶。每台的容量为1吨，可以测试55英寸见方、16英寸厚的钢筋混凝土板。一般桁架模型理论的建立与有限元方法相结合，将允许人们预测整个范围的结构在膜应力（墙和壳）下的行为。

Shear action is an important factor in the failure of reinforced concrete structures. A softened truss model theory has been developed that is capable of predicting the behavior of various types of structures when shear is predominant. The first objective is to generalize the softened truss model theory so that it can be applied to situations where shear (torsion) is combined with axial loads. The second objective is to perform tests on 40 full.size reinforced concrete panels in order to determine the material laws required in the general theory, including the softening law, the constitutive law of cracks, and the law governing the contribution of concrete. The research will be carried out in a $440,000 panel.testing facility recently completed at the University of Houston. This facility consists of a giant steel frame embedded with 40 jacks of 100.ton capacity each, which can test reinforced concrete panels 55 inches square and up to 16 inches thick. Establishment of a general truss model theory in conjunction with the finite element method will permit one to predict the behavior of a whole range of structures subjected to membrane stresses (walls and shells).