STUDY AND NUMERICAL SIMULATION OF THE BOUNDARY ELEMENT MESH IN THE CRACK GROWTH PATH
Stephanie Cristina Matos Pereira1; Gilberto Gomes1
1 Universidade de Brasília
doi:10.20906/CPS/CILAMCE2017-0291
Resumo
A wide variety of structures, such as aircraft structures, rocket launchers, ships and metal bridges, are constantly submitted to conditions that are predisposed to generate fatigue cracks. Those cracks increase gradually due to the cyclic loads application. In addition, it is impracticable to preserve the structures without its presence, but the structural integrity can be assured providing an exchange and repair of components when it reaches a critical size. The presence of cracks on the structure cause complications in the use of Linear Elastic Fracture Mechanics (LEFM) related to the modeling process and the calculation of stress intensity factors (SIF) as well. In this sense, numerical techniques based on finite elements method (FEM) and boundary elements method (BEM) have been applied on this type of problem. Here, in order to analyze the structures that an interaction between cracks, holes and/or inclusions leads to the continuous change in the geometry of the problem, the BEM has been applied in its dual form (DBEM). The methodology consists in analyze the influence of boundary elements mesh over the crack growth path using several models extracted from the open literature, being modified some parameters as holes, cracks tip size, J-Integral radius and others, aiming to obtain a convergent mesh. In addition, the BEMLAB2D GUI for pre- and post-processing and BemCracker2D program based on DBEM analysis has been used to the verification of the methodology adopted, in which SIF results have shown the accuracy and validation of the study.
Palavras-chave: crack growth; SIF; DBEM; boundary mesh; modelling