An inverse strategy to determine constitutive parameters of tubular materials for hydroforming processes

This paper is to determine the flow stress curve of 5049-O aluminium alloy by a tube hydraulic bulging test with fixed end-conditions. During this test, several tubular specimens are bulged under different internal pressures before their bursting, and corresponding height wall thickness at pole measured. An inverse strategy developed constitutive parameters materials based on experimental data, which combines finite element method gradient-based optimization techniques. In scheme, objective function formulated sum least squares error between numerical difference approximation used calculate gradient. The material behavior assumed meet von Mises yield criterion Hollomon exponential hardening law. Then, identification performed minimization function. order validate performance framework, identified compared those obtained two types theoretical models, tensile tests cut from same tubes. comparison shows that framework robust can achieve more accurate parameter eliminating mechanical geometrical assumptions in classical analysis.