Análise numérica em paredes de alvenaria estrutural com cortes horizontais através de modelos de LDEM em estado plano de deformações

Abstract

The execution of chases in structural masonry walls often occurs due to the need to carry out the passage of electrical, hydraulic, gas, among others. Even today, chases are made without forecast in projects, thus causing a decrease in the resistance capacity of the walls. In this way, the present word aims to study a simplified model in plane deformation state (2D), to obtain the mechanical behavior of structural masonry walls with horizontal sections, through numerical simulations, using the Lattice Discrete Element Method (from the English LDEM). For this, the properties of the material and the mesh were defined to perform the numerical simulations more efficiently. Different heights of horizontal chases were simulated in the walls, different depths of horizontal chases, being them, 20%, 30% and 50% of thickness. Different boundary conditions were also simulated, such as: labeled-labeled and crimped-labeled. The load application eccentricity was also changed. As results we have: the mesh length that came closest to the experimental results used as parameters for the analysis of this study were the mesh lengths of 2.8 and 2.0 mm, with a viable computational effort, and the length of 2 .0 mm was chosen. Analyzing the labeled-label boundary conditions with shear and central loading, it was verified that the crack starts at the cut and propagates symmetrically up and down, while with the fixed-labeled condition, the crack also starts at the chases, but it propagates upward until it reaches the upper support and then descends to the lower support. Another important conclusion is that when the labeled-labeled or crimped-labeled boundary conditions are simulated, for simple or mixed models, the failure configuration is always similar, between the models with the same boundary condition, already when the models are simulated. Mortar and block discretized the failure configuration mode is different. Analyzing the center chase or top chase with eccentric loading, the crack starts at the cut and propagates to the top of the wall, regardless of the boundary condition that is simulated. Keywords: chases, numerical simulations, structural masonry, mechanical behavior, LDEM.