PSI - Issue 2_B

W. Rekik et al. / Procedia Structural Integrity 2 (2016) 3491–3500 Author name / Structural Integrity Procedia 00 (2016) 000–000

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Fig. 5. Illustration of the numerical definition of the tensile behavior laws

A procedure is developed using the Cast3m software [http://www-cast3m.cea.fr/] to allow a systematic assignment of the material constitutive behavior. A schematic illustration of the procedure performed is provided in Fig. 5. To reproduce the experimental boundary conditions, the point P1 is constrained along the x-direction and the load is imposed through vertical displacement at point P2 which is restrained from displacement along x-direction (Fig. 5). 3.3.2. Results and discussion A proper η factor for each configuration of initial crack is numerically defined. Numerical and experimental results of an initial crack configuration within the HAZ are reported in Fig. 6. The two major results are the following:  The numerical model assumptions, particularly the attributed tensile behavior, allow a good reproduction of the experimental load versus crack mouth opening displacement curves up to crack initiation (Fig. 6a),  The asymmetrical development of plasticity by the presence of the soft fusion zone has a considerable impact on the η factor identification and in consequence, on the J-crack extension curves (Fig. 6b). Hence the high interest of numerical analysis for the interpretation of J1 c experimental results.