Effect of different yield criteria on prediction of wrinkling initiation of interstitial-free galvanized steel sheet

摘要

Thin interstitial-free (IF) galvanized steel sheets have great usage in auto industry due to their high form-ability and corrosion resistance. However presence of wrinkle waves in deep drawn parts of thin IF steel sheets is a common challenging issue. Achieving a reliable method to predict the wrinkling onset enables the manufacturers to avoid wrinkling by modification of forming parameters. In the present study, side-wall wrinkling of an IF-galvanized steel sheet was both analytically and experimentally examined during a conical cup wrinkling test. Using an energy method approach together with a newly developed deflection function, Hosford and Hill-1948 yield criteria were employed to predict the critical values of stress and cup height at the onset of wrinkling. According to the obtained results, applying Hill-1948 yield criterion resulted in prediction of wrinkling onset closer to the experimental value than Hosford yield criterion. It was also found that the newly presented deflection function has a great suitability for prediction of the real status of wrinkling phenomenon.