A 3-DIMENSIONAL FINITE-ELEMENT ANALYSIS OF HYDROSTATIC BULGING OF AN INTEGRAL POLYHEDRON INTO A SPHERICAL VESSEL

The recently developed integral hydro-bulge forming (IHBF) process has been introduced as a novel method of manufacturing single- and multi- layered spherical pressure vessels. The process of manufacturing spher ical vessels using IHBF is rather simple in application but complex in analysis. Thus far, all studies and analyses have been experimental. The interaction of welds and flat plate elements during the hydrostati c bulging process and the ensuing state of stress and large deformatio n constitute a complex three-dimensional metal forming process that is not understood well. In this study, a three-dimensional finite elemen t model of the IHBF process used in manufacturing of spherical pressur e vessels is developed using the ABAQUS finite element code. The resul ts of the forming simulation and its comparison with experimental obse rvations as well as the deformation history in the flat plate elements are presented in this paper.