Calculation of the compensation of a stamping tool after springback in the software package pam-stamp

Excerpt

Sheet-stamping processes include complex technological operations which ensure that the product has the requisite shape and prescribed set of properties. Because sheets are relatively thin but are used to make products with relatively large dimensions, one important problem in creating the geometry of the product is its elastic deformation during the stamping operation – its springback. The amount of springback depends on many factors, among them being the mechanical properties and condition of the material of the sheet, its measured thickness, the form of the part (product) being made from it, the bending radii, and the angles and depth of inclination of the walls of the die. The multiplicity of factors makes it almost impossible to create exact design formulas for complex cases involving the bending and stamping of products. Accordingly, springback can be evaluated only by using the available empirical data and compensating for the tool on the basis of that evaluation. The final estimate that is obtained by this approach is highly approximate, and use of the data to adjust the tool does not always yield positive results in the first attempt (in particular, when it is necessary to correct different local sections of the tool, it is difficult to then later compensate for the tool as a whole). Thus, it becomes necessary to make a certain number of semifinished products and to repeatedly remove, regrind, and re-install the thus-corrected tool. …