Non linear finite element simulation of explosive welded joints of dissimilar metals for shipbuilding applications

A procedure to simulate the non-linear behavior of explosion welded joints used for shipbuilding applications, starting only from hardness measurements, was developed. The explosion welded joints consist of three different materials: ASTM A516 structural steel, AA5086 aluminum alloy and an intermediate layer of pure aluminum. Three point bending tests were carried out on explosion welded joints with and without an initial notch. The Digital Image Correlation, which is a non-contact full-field technique, was applied in order to measure the displacement and strain patterns of the different metals during the bending tests. Non - linear finite element analyses were performed. The stress-strain curves of the materials, applied in the finite element model, were obtained using Ramberg Osgood type equations and considering the results of the micro-hardness measurements, which were correlated to the mechanical properties of the different materials. The finite element model was validated experimentally, comparing the results with the measurements obtained using the Digital Image Correlation technique. Furthermore, the procedure was extended to a specimen with an initial notch, for which the FE results were compared to the experimental tests.