Análise quase-estática e de fadiga em juntas coladas usando modelo de zona coesiva (CZM)

• Ano de defesa: 2018
• Autor(a) principal: Murilo Ferreira Brandao
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Minas Gerais; UFMG
• Palavras-chave em Português: Fadiga; Juntas coladas; CZM; Materiais compósitos; Propagação de trinca; Engenharia de estruturas; Materiais compostos; Juntas (Engenharia); Materiais fadiga
• Link de acesso: http://hdl.handle.net/1843/RAOA-BELQAV

In this paper numerical simulations were performed for tensile and fatigue analyzes of high cycle in bonded joints using composite materials as adhesives. For this, an algorithm was developed using the UEL subroutine in Abaqus® to add a damage model using cohesive elements when the structural component is requested by cyclic loads. This work is important because of the increasing use of bonded joints using composite materials in aeronautical, automotive and other industry segments. The reasons for this growth are some advantages over mechanical joints such as weight, fatigue strength, lower maintenance cost. In order to numerically represent the behavior of crack propagation and damage in the bonded region, the cohesive zone model (CZM) will be used. The reason for the choice is justified, since the CZM presents the main advantage, in relation to other models of classics of finite elements like VCCT and XFEM, the computational time. As a result, bonded joints for mode I were subjected to quasi-static and fatigue loading. The numerical and experimental values of the tensile stresses, the crack propagation rate and the number of joint life cycles were compared. In the quasi-static analysis, adjustment parameters for the CZM model were studied, such as cohesive stiffness and cohesive zone length, whose results showed the influence of their values on the traction-separation curve in the cohesive region for the DCB model and the influence on the distribution of normal and shear stress for the SLJ model. For the analysis of fatigue using CZM, the numerical model presented by Turon (2006) was applied with which it was possible to compare, by means of experimental data, the crack growth rate for different loading ratios, as well as the accumulation of the damage to the cohesive element caused by the cyclic loading.