Nonlinear Finite Element Analysis Of The Mechanical Performance Impact Of Structural Opening On The Brick Masonry Wall

At present brick structure is still dominant in the urban, rural, backward areas, this situation will not change in a fairly long period of time. The seismic research of brick structure is still an important task for civil engineering. Brick structure is a kind of typical brittle structure, high self-importance, high stiffness, high earthquake effect, low shear, low tensile strength, low flexural strength, under the earthquake the structures crack, even destroy, seriously affecting the structure of life. Especially in wall with holes, under the action of earthquake, the holes will appear obvious stress concentration, the stress performance of components is reduced, the holes become the weak parts of the wall, which has great theoretical significance and practical value to research the effect of the hole on the wall mechanical performance of masonry-concrete structure.This paper expounds the characteristic of masonry-concrete structure, the present situation of development and seismic measures firstly, then introduces the theory of material mechanics performance and finite element analysis of masonry structure, then summarizes the previous studies to do some discussion and analysis on mechanical properties effect of the hole on the wall by using the universal and finite element analysis software ABAQUS, the main contents are as follows:1. The wall of shear-pressure effect as an example. When the hole size, hole shape, hole arrangement, hole horizontal position, hole vertical position and other parameters are different, analyzes in detail the content on stress distribution, displacement, ultimate load and stiffness, it gives the best choice of hole size, shape, position and cracks distribution with and without the wall. Analysis shows that being compared with the hole shape, hole position and hole arrangement, the hole size has a greater effect on the mechanical performance of the wall.2. Two kinds of the wall with and without opening under shear pressure as examples, when the wall height-width ratio is different, it analyzes displacement, ultimate load, stiffness and stress distribution of the wall under each step loading. Analysis shows that with the wall height-width ratio increasing, carrying capacity of the shear decreases, but bending effect of the specimen gradually enhances, deformation capacity and ductility improve.3.The wall with rectangular opening under shear-pressure as an example, when the hole size, the span-height ratio of the wall under the window, the height-width ratio of the wall between the window and other parameters are different, analyzes in detail the wall stress distribution, cracks distribution and development. Analysis shows that with the span-height ratio of the wall under the window or the height-width ratio of the wall between the window increasing, the cracks of the wall at the bottom will increase; most walls show that the damage of the wall bottom is far greater than the wall top; with the opening rate becoming greater, mechanical performance of the wall between and under the window all decline; X shaped cracks of the wall under the window is compared with damage of two sides, X shaped crack is more suitable for the structure seismic.Finally, this paper gives the research results and puts forward the problems needed to be solved according to the research results. The purpose of this work is to analyze the effects of the hole on the wall mechanical performance of masonry-concrete structure and provide certain reference on the research of masonry structure with openings and design work in future.