Development of an index model for oil canning of steel sheet metal forming products

Abstract

A buckling of the thin plate after stamping process is called an oil canning phenomenon. This issue impacts the shape and induces vibration and noise effects on the outer surface of the stamped parts such as the automobile and white-good products. To answer the call for reducing the oil canning, the results of a number of experimental procedures carried out on two largely utilized steel, namely the AISI-1008 and AISI-1020 steel alloys are used to define an empirical-numerical model for the prediction of oil canning in the design stage. The results of the tests on those two steel are utilized for the definition of the process parameters which can be directly linked to the rise of the oil canning phenomenon on metal sheets. Accordingly, in this paper, the thickness, the curvature radius, the length, and the width of the panel are considered the most influencing parameters in the arising of oil canning issue. A stamping process is carried out, and an indentation test is applied to check the oil canning on the stamped sheets. In addition, the measurements on assigned points on the stamped panel for thickness and curvature radius are carried out. Afterward, based on the experimental results, numerical simulations have been implemented in LS-Dyna and the results are utilized for the definition of an oil canning index (OCI) model that is used to define the higher or lower risk of oil canning occurrence when a certain combination of material and process parameters are utilized. In the proposed model, an OCI close to zero defines a condition where oil canning is unlikely to happen whereas an OCI close to one or higher stands for high risk of oil canning to arise. The obtained oil canning values are correlated with the curvature radius results which found to be the most considerable effect on the oil canning occurrence.