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开发了一种对玻璃钢条加强砌体结构的倒塌荷载和失效机理进行数值预测的三维均质有限元软件。它采用两个步骤:第一步,借助典型体单元(REV)中的容许动态有限元方法求得均质砌体的失效面;这种单元由一块体构成,此块体通过有限厚度的砂浆节点与其六相邻体相连接。采用与摩擦性能和有限拉、压强度相关联的8结点的无限抗力的平行六面体单元,形成REV单元。这样可得出一仅有少数变量的简单线性规划问题,适宜重新获得在平面内外加载时砌体失效面的数值解。第二步,在新型动态有限元软件中实现均质失效面对整体结构倒塌荷载的经济评估,考虑了FRP砌体界面上有限抵抗力模型的脱层作用,这与意大利规范CNR-DT-200是一致的。用6结点无限刚性三维楔状单元模拟均质砌体,而用三角形的3结点刚性单元来模拟FRP条。在格鲁吉亚对各类方法用FRP条加强并经过准静态水平荷载下测试的两层砌体结构进行了分析。分析结果表明,无论有没有加强,结果都吻合较好。这说明开发的程序可用于分析复杂的三维加强砌体结构的倒塌荷载和失效机理。
A three-dimensional homogeneous finite element software was developed to predict the collapse load and failure mechanism of FRP reinforced masonry structures. It takes two steps: The first step is to find out the failure surface of a homogeneous masonry by means of a permissible dynamic finite element method in a typical body unit (REV) consisting of a block that passes through a finite thickness mortar The node is connected to its six adjacent bodies. An 8-point infinitely-resistive parallelepiped unit associated with frictional properties and limited pull and compressive strength was used to form a REV unit. In this way, a simple linear programming problem with only a few variables can be obtained, which is suitable to regain the numerical solution of the failure surface of masonry when loaded in and out of plane. The second step is to realize the economic evaluation of homogeneous failure in the new dynamic finite element software in view of the collapse load of the whole structure, considering the delamination effect of the finite resistance model on the FRP masonry interface, which is in line with the Italian specification CNR-DT-200 Is consistent. Homogeneous masonry was modeled by a 6-node infinitely rigid three-dimensional wedge cell, while a triangular 3-node rigid cell was used to model the FRP bar. Two-story masonry structures reinforced with FRP bars and tested under quasi-static horizontal loading were analyzed in Georgia. The results show that, with or without strengthening, the results are in good agreement. This shows that the developed program can be used to analyze the collapse load and failure mechanism of complex 3D reinforced masonry structures.