A forming limit criterion with non-proportional loading of aluminum alloy sheet for convenient engineering application
On the basis of in-depth analysis of thickness thinning rate of sheet metal reaching the forming limit under proportional and non-proportional loading paths,a forming limit criterion based on the thickness thinning rate was proposed.For 5086 and 6111T4 alumi-num alloy sheets,the forming limit thickness thinning rate diagrams were drawn by fitting the relationship curves between different strain ratios and thickness thinning rates under the linear loading paths,and the forming limit diagrams under the complex loading paths were predicted.The results show that the forming limit criterion based on thickness thinning rate can reasonably predict the movement direction of the forming limit curves under different loading paths.Within a certain pre-strain range,the forming limit thickness thinning rate dia-grams are not affected by the loading paths,but when it exceeds this range,the forming limit thickness thinning rate diagrams still show dependence on the loading paths.Therefore,in industrial production,the forming limit thickness thinning rate diagram is suitable as the forming limit criterion in the loading path without large pre-strain,otherwise the influence of the loading path on the forming limit still needs to be considered.
forming limitthickness thinning rateproportional loadingnon-proportional loadingconstitutive model
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维普
