Necking Prediction in Tube Hydroforming by Stress-Based Forming Limit Diagrams
Path-independent stress based forming limit diagrams for anisotropic materials along with the Hill 48 yield function; power law strain hardening and isotropic hardening are derived. Bifurcation analyses via solving equilibrium equations of a pointed vertex on subsequent yield loci are utilized. The presented practical forming limit diagrams (FLSDs) show more acceptable agreements with experimental data compared with those obtained by other methods. A typical neck detection macro in APDL is developed by FEA simulation for a free bulge tube hydroforming to confirm the significant simplicity and straightforwardness of the mentioned FLSD.
Ahmad Kamal Ariffin, Shahrum Abdullah, Aidy Ali, Andanastuti Muchtar, Mariyam Jameelah Ghazali and Zainuddin Sajuri
A. Jaamialahmadi and M. Kadkhodayan, "Necking Prediction in Tube Hydroforming by Stress-Based Forming Limit Diagrams", Key Engineering Materials, Vols. 462-463, pp. 284-288, 2011