PSI - Issue 17

Elena M. Strungar et al. / Procedia Structural Integrity 17 (2019) 965–970 Author name / Structural Integrity Procedia 00 (2019) 000 – 000

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a c Figure 2. Geometry and boundary conditions of the plate ( a ), mesh around the hole with n =6 ( b ), the diagram of mesh convergence ( c ). The solution of the problem was carried out in the finite element software package Ansys. A two-dimensional four node PLANE 182 finite element was used in the model. Due to the presence of stress concentration, the finite element mesh thickened around the hole. The accuracy of the numerical study was achieved by conducting a preliminary analysis of the convergence of the solution when the mesh was thickened in the region of the hole. In this case, 6 types of meshes with a different number of finite elements n along the hole line shown on Figure 2b were considered. These mesh illustrate only the plate area around the hole. Mesh density was defined as the number of finite elements located on the hole line. The diagram of mesh convergence is presented in Figure 2c, where the stress is the stress in the most loaded finite element, defined by the von Mises formula. As can be seen from the figure, the mesh thickening does not lead to a significant change in the results. Since a fine mesh leads to a more accurate distribution of stresses around the hole, a grid with 24 elements along the hole line was taken as optimal. Figure 3 a, b shows the distribution fields of the longitudinal deformations obtained by solving a numerical problem, as well as experimentally using the method of digital image correlation, with a load of 51 kN. The fields obtained in the simulation illustrate the qualitative agreement with the experimental results. The photo presented in Figure 3c reflects the destruction of the fibers in the transverse direction in the area of the stress concentrator. This result is consistent with the pattern of distribution of calculated and experimental strain fields in the early stages of deformation.