Analysis of the thinning phenomenon variations in sheet metal forming process

In many manufacturing areas such as the automotive industry (outer panels, inner panels, stiffeners etc...), the packaging industry (petfood containers, beverage cans etc...) and the household appliances industry (housings etc...), the control of the thinning variations in sheet metal forming process is a major point to study in order to ameliorate the final quality of the produced parts. In this framework, several bulge tests have been developed in order to study the thinning phenomenon during sheet metal forming processes. In this presentation, measurement of the thickness of the deformed specimens has been done using the ImageAnalyser software (based on an image analysis technique) developed by the CMAO research group in the LGP. The AISI 304L stainless steel has been selected as the tested material. Both a cylindrical and an elliptical die allowing the analysis of the thickness variation versus the load ratio and the anisotropy of sheet have been used in this work. In a second part of this communication, we present a numerical model based on the Hill 1948 anisotropic material model. The numerical results are discussed and compared with the experiments