Issue 35

O. Demir et alii, Frattura ed Integrità Strutturale, 35 (2016) 330-339; DOI: 10.3221/IGF-ESIS.35.38 332 Modeling, meshing, defining loads, boundary conditions and contacts and the solution of the problem involving the whole assembly, i.e., loading devices, pins and the specimen, with contact mechanics are performed using ANSYS TM [15]. To simulate the real conditions in the experiments, contacts are defined between the contact surfaces of the loading devices, bushes, specimen and pins (Fig. 2). Figure 2 : Contact and target surfaces between the mode-I clevises, mixed-mode clevises, bushes, specimen and pins. Also to provide the real conditions of experiments, boundary conditions are defined such that the bottom mode-I clevis surface nodes are constrained in all directions and the upper mode-I clevis surface nodes are allowed to move along loading axis only (Fig. 3). Load is applied on the upper loading clevis. Representative picture given in Fig. 3 is for 75° loading angle. Figure 3 : Boundary conditions and loading on mode-I/II test system – loading angle 75°. Having obtained the overall solution using ANSYS, displacements are taken from nodes of the specimen loading hole surface by using submodeling. Then these displacements are applied on the specimen model, which is used in FRAC3D solver to calculate the resulting stress intensity factors (Fig. 4). Figure 4 : Applying the submodeling approach and transfer of the specimen and crack tip node and element files to FRAC3D.