Deep drawing of pressure vessel end closures: finite element simulation and validation

The development of tooling for the deep drawing of pressure vessel end clos ures (PVECs) can be a time-consuming and expensive process. Finite element (FE) modeling of this process has the potential to reduce these costs. Acco rdingly, a parametric model of the forming of PVECs on a 500 t hydraulic pr ess at C.E. MacPherson (a division of Conrex Steel) of Kingston, Ontario ha s been developed using the commercial FE software, MARC. The tooling is mod eled as rigid surfaces. The workpiece is modeled as a deformable body using a quadrilateral axisymmetric element. The plastic stress-strain characteri stics are based on tensile-test data fitted to the Ludwik-Hollomon hardenin g law. Isotropic material, isotropic hardening and the Prandtl-Reuss flow r ule are assumed. A mesh-refinement study is conducted to determine the opti mal FE mesh. Sensitivity studies of the effects of the Coulomb friction coe fficient and the blank-holder gap are also conducted. The FE results for tw o sizes of PVECs are validated by comparison with in-process parameters (pu nch displacement, punch force, and blank-holder force) and post-process (pa rt profile, thickness-strain distribution, and surface-strain distribution) forming data. (C) 2000 Elsevier Science S.A. All rights reserved.