Cyclic Behavior of Concrete Shear Walls: A Rational Approach

9711084徐从过去地震中结构破坏的证据清楚地表明，剪力墙为地震区的建筑物提供了良好的保护。本项目旨在开发一种合理的方法来理解和预测低层剪力墙和框架剪力墙在循环荷载作用下的行为。这种方法背后的总体概念是，剪力墙作为一个完整的系统，其复杂的行为可以通过整合通过实验获得的关于其部件和部件的知识来阐明，这些部件和部件被可视化为膜元件(面板)的组装。将研究单个膜单元的应力-应变行为，以建立物理模型和分析模型。然后将得到的模型集成到有限元程序中，以计算和预测特定条件下整个剪力墙的荷载-变形行为。1988年，休斯顿大学建造了一台独特的万能面板测试仪，它特别适合于预期的测试。将进行25个墙板在循环荷载作用下的试验程序。膜单元的循环试验结果将被用于建立混凝土的循环本构关系。在El-Borgi建立的分析模型中，将确定混凝土的性能，如刚度劣化、强度劣化和滞回环的“收缩”，然后用来校准它们的相应参数。然后，校准后的滞回模型将使编制的非线性有限元计算机程序能够用于预测整个剪力墙的性能。美国休斯顿大学和突尼斯理工学院将联合开展这项研究。***

9711084 Hsu Evidence from structural failures in past earthquakes clearly shows that shear walls offer excellent protection to buildings in seismic regions. This project is to develop a rational approach to understanding and predicting the behavior of low-rise shear walls and framed shear walls under cyclic loading. The overall concept behind this approach is that the complicated behavior of shear walls as a whole system, can be elucidated by integrating what can be learned, experimentally, about its parts and components, visualized as being an assembly of membrane elements (panels). The stress-strain behavior of individual membrane elements will be studied to establish physical and analytical models. The resulting models will then be integrated into a finite element program to compute and predict the load- deformation behavior of whole shear walls under specified conditions. A unique universal panel tester was constructed at the University of Houston in 1988 which is especially suited for the intended testing. A test program of 25 wall panels subjected to cyclic loading will be carried out. The results from the cyclic tests on membrane elements will be used to establish the cyclic constitutive laws of concrete. Concrete behavior such as stiffness deterioration, strength deterioration, and "pinching" of hysteretic loops will be determined and then used to calibrate their corresponding parameters in an analytical model established by El-Borgi. The calibrated hysteretic models will then enable a nonlinear finite element computer program be formulated, which can be used to predict the behavior of whole shear walls. The University of Houston in the United States and the Polytechnic School of Tunisia in Tunisia will jointly carry out this research. ***