title: Prediction of Burst Pressure in Multistage Tube Hydroforming of Aerospace Alloys.
abstract: Bursting, an irreversible failure in tube hydroforming (THF), results mainly from the local plastic instabilities that occur when the biaxial stresses imparted during the process exceed the forming limit strains of the material. To predict the burst pressure, Oyan's and Brozzo's decoupled ductile fracture criteria (DFC) were implemented as user material models in a dynamic nonlinear commercial 3D finite-element (FE) software, ls-dyna. THF of a round to V-shape was selected as a generic representative of an aerospace component for the FE simulations and experimental trials. To validate the simulation results, THF experiments up to bursting were carried out using Inconel 718 (IN 718) tubes with a thickness of 0.9 mm to measure the internal pressures during the process. When comparing the experimental and simulation results, the burst pressure predicated based on Oyane's decoupled damage criterion was found to agree better with the measured data for IN 718 than Brozzo's fracture criterion.
authors.affiliation: National Research Council of Canada, École de technologie supérieure, Montréal, QC H3T 2B2, Canada.
authors.forename: M
authors.initials: M
authors.lastname: Saboori
authors.affiliation: National Research Council of Canada, Montréal, QC H3T 2B2, Canada.
authors.forename: J
authors.initials: J
authors.lastname: Gholipour
authors.affiliation: École de Technologie Supérieure, Montréal, QC H3C 1K3, Canada.
authors.forename: H
authors.initials: H
authors.lastname: Champliaud
authors.affiliation: National Research Council of Canada, Montréal, QC H3T 2B2, Canada.
authors.forename: P
authors.initials: P
authors.lastname: Wanjara
authors.affiliation: Laval University, Québec, QC G1V 0A6, Canada.
authors.forename: A
authors.initials: A
authors.lastname: Gakwaya
authors.affiliation: Pratt & Whitney Canada, Longueuil, QC J4G 1A1, Canada.
authors.forename: J
authors.initials: J
authors.lastname: Savoie