A Procedure for Ductile Damage Parameters Identification by Micro Incremental Sheet Forming

Incremental sheet forming is an important process that allows versatile parts without specific tools [1]. The micro-incremental sheet forming process (mu SPIF) is the miniaturization of the classical single point incremental sheet forming process (SPIF). After a brief presentation of the specific properties of the mu SPIF process, the ability of this technique to identify the ductile damage properties of the material under severe deformation process is presented [2]. mu SPIF is then investigated as a method to identify the material parameters of a Lemaitre's ductile damage evolution law. The identification procedure is based on the comparison between numerical simulations of mu SPIF tests [3] and experimental data [4]. The error function to be minimized is initially computed as a L2-norm of the error between numerical and experimental forming forces, then after extended by full field measurements. A parameter sensitivity analysis of the numerical model is performed. An identifiability method, based on that proposed by Richard et al. [5] for indentation tests is used to quantify the influence of each data and demonstrate the meaningful mechanical properties obtained. Different numerical tests (line tests, indentation tests, truncated shape, Meuwissen tests and Out-of-Plane testing procedure by T. Pottier [6]) are also investigated. (C) 2017 The Authors. Published by Elsevier Ltd.