Formability Testing Of Sheet Metals

Mechanics and metallurgy third edition.

Formability testing of sheet metals.

Sheet metal formability tester ductility tester cupping test drawing cup test iso 8490 en 14 58 en 14 67 din 50 101 din 50 102 bs 3855 1965 nf a 03 602 nf a 03 652 astm e 643 84. The testing procedure is further explained in this article. Formability refers to the ability of sheet metal to be formed into a desired shape without necking or cracking. Necking is localized thinning of the metal that is greater than the thinning of the surrounding metal.

How ever the closer the magnitude of the two stresses the more work hardened is the metal. However in order to have a measure for sake of comparison the limit drawing ratio ldr is taken as a measure of drawability. Both the tests stretch the sheet over a hardened steel ball and the height of the produced cup at failure is the measure of the material. There are many tests of formability for sheet materials.

The old saying garbage in garbage out rings true in this regard. In this chapter 1 sheet metal formability tests such as the tensile test the plane strain test and the in plane stretching test are analyzed. The fem and experimental methods were used in order to demonstrate how two dimensional in plane simulation can help interpret and develop such tests as well as to understand the nature of material behavior and governing mechanics. The erichsen test and the olsen test are cupping tests and were the first to be developed for estimating the sheet metal stretchability namely the sheet metal formability under stretching conditions.

Sheet metal forming simulation is almost meaningless without accurate material data. A given test may correlate well with behavior in one type of forming process and poorly with behavior in another. Norwood ma 02062 tel. From the metallurgical perspective the formability of a particular metal depends on the metal s elongation which.

This article presents an overview of types of forming formability problems and principal methods of measuring deformation. Sheet metal forming operations are so diverse in type extent and rate that no single test provides an accurate indication of the formability of a material in all situations. The mechanical properties of the sheet material greatly influences its. Formability of sheet metal is the ability of sheet metal to be drawn into cups or formed into the desired shapes without any defect.

To correctly and accurately capture the mechanical properties of material for use in simulation a tensile test is performed. Astm e646 stan dard test method for tensile strain hardening exponents of metallic sheet materials gov erns the determination of the strain hardening exponent. This is because the relative.