PAMSTAMP2G-based Research On Forming Region And Formabiiity Division Of Sheet Metal Stamping

Sheet metal stamping is a very important method of metal processing, it builds on the basis ofplastic deformation of the metal, taking advantage of the molds and stamping equipment for sheetmetal processing, in order to obtain the desired shape and size of the parts. Sheet metal stampinghas a series of advantages, such as high productivity, low cost, stable product dimensional accuracy,simple operation, easy to implement mechanization and automation, therefore, it has been widelyused in machinery, electronics, light industry.Most of the sheet metals must experience plastic processing, through which they can form intovarious shapes of parts, so that they can be used on products, therefore, the main problems anddifficulties during sheet metal processing are mostly about forming aspects. In the sheet metalforming process, defects, such as wrinkle, crack and springback, may appear, which has a great linkwith material formability, formability of sheet metal is directly related to the cost and performanceof products. Formability of sheet metal refers to the ability to adapt to the sheet metal stampingprocess, including crack resistance, fittability, shape fixability.The maximum deformation degree of sheet metal that can be achieved before the instability iscalled sheet metal forming limit, forming limit divides into general forming limit and local forminglimit, the degree of forming limit the most important indicator of the formability of sheet metal. Asto complex deformation parts, due to the large difference in the deformation of the blank, usinglocal forming limit to describe the extent of each point on the blank is necessary, only in this way,the deformation situation of the blank during stamping process can be correctly judged. Forminglimit diagram shows the non-uniform deformation local limit of the sheet metal, it is a strip-shapedregion or a curve, which consists of local instability limit strain at different strain paths, it fullyreflects the local forming limit of sheet metal under unidirectional and bidirectional tensile stress,and it is an important tool to overcome stamping defects such as cracking and wrinkling.Early research method in metal forming is mainly based on the test analysis method,formability of metallic materials are determined by testing. With the improvement of the theorysystem of metal forming and the development of computer science, research on numericalsimulation of sheet metal forming has been rapidly developed. The applications of numericalsimulation of sheet metal forming, combined with the practice verification, can effectively forecast against defects, such as wrinkling, cracking, springback and others, that may arise in sheet metalforming, and get the optimized process parameters, in order to guide the actual production, it caneffectively shorten the product development cycle and reduce development costs.This paper bases on the theoretical knowledge and experimental methods describes in"stamping technology" and the national standard GB/T15825" formability and test methods ofsheet metal ", using numerical simulation software of sheet metal PAMSTAMP2G, for the testmethods that measuring the formability of sheet metal, including drawing test, hole expanding test,bending test, conical cup test, earing test, erichsen cupping test, to conduct numerical simulationand analyze the results of the forming, so that the process of changing of the forming methods, aswell as the analog value formability index of sheet metal, including LDR, limit expansion rate,minimum relative bending radius, IE, CCV, earing rate can be obtained, finally, comparing themwith the actual test results for verification.