Analysis Of Hydro Formed Complex Shape Parts Using A Ductile Fracture Criterion.

Nowadays the Hydro Forming techniques have been largely accepted by industries for the production of components characterized by complex shape, good surface quality, near net shape and low volume batch. In particular the Sheet Hydro Forming (SHF) process offers the possibility of no restrictions in the final shape of the part. This is the reason why a deeper investigation on the chance of using the SHF process for the production of complex shaped parts could be of great interest. In this work, the authors have considered as case of study a compound part which is made of a cylindrical region (the base) connected to a square part (the protrusion). Experimental and numerical activities have been performed. In particular, a commercial Finite Element (FE) code has been chosen to simulate the SHF process; a stress-strain based damage variable according to the Oh’s criterion (derived from the Cockroft and Latham one) has been also used to evaluate the process limits. The Critical Damage Value (CDV) of the steel adopted for the analysis (AISI 304) has been set using experimental test results. The critical regions and the blank thinning have been analyzed for different geometrical configurations of the compound die cavity. Thus, a complexity shape factor has been defined. © 2004 American Institute of Physics [ABSTRACT FROM AUTHOR]