砌体等效断裂韧度的实用解析方法研究

根据砌体准脆性材料的断裂特性,提出了一种基于竖向灰缝模型的求解砌体等效断裂韧度的实用解析方法.首先根据复合材料力学和线弹性断裂力学的基本原理,运用修正的剪滞理论,分区引入变异层,建立了分层剪滞模型;然后根据能量法则,推导出了求解无筋砌体等效断裂韧度的解析计算模式;最后针对相关试验数据,得到了对应数值解的解析解,且与相关试验对应的数值解相比,解析解的均方差和变异系数更小,由此可以看出,本文的解析方法具有很好的鲁棒性.结果还证明了无筋砌体等效断裂韧度是与试件尺寸无关的断裂参数.该方法为砌体结构开裂机理的研究和发展,砌体结构力学性能的研究提供了新的技术路径.

Study on the equivalent fracture toughness of mansory with a practical analytical method

According to the fracture property of the quasi-brittle material of masonry, a practical analytical method of the equivalent fracture toughness of masonry is established based on the vertical crack model. At first, according to the basic principles in the composite material mechanics and the linear elastic fracture mechanics and based on the modified shear lag theory and by introducing the variable layer in different zones, the layered shear lag model is built. Then based on the energy law, an analytical form to solve the equivalent fracture toughness of masonry is derived. Finally in view of the solutions of the related experiments, the analytical solutions of the equivalent fracture toughness of masonry are obtained. The results show that in the case of varying sub-layers, the equivalent fracture toughness of masonry is a size-independent fracture parameter. It provides a new technical way for the study and development of the cracking theory and the mechanic properties of the masonry.