How does simulation show sheet metal wrinkling?

News Release from: StampingSimulation.com Pty Ltd
11/02/2008

This is a good question and certainly worth further discussion.

When assessing wrinkles in forming simulation, it is important to understand how a wrinkle is “displayed”. A serious wrinkle (ie: metal folding, scrunching together) will show up very clearly. If the material is predicted to fold, within the FEA mesh of the simulation, folding will be observed very clearly. This is an example of a serious, folding wrinkle found with simulation. Note that the ability to visualize a wrinkle in this manner is unique to full incremental forming simulation technology, that is, one-step based solvers are unable to show a wrinkle in this manner.

Surface waviness (”wrinkles”) are usually detected via the FORMABILITY color scale and are usually very minor, with the purpose being to detect even the smallest of imperfections to achieve automotive A class skin panel finish. This is when the colors BLUE and PURPLE are used, but the direct meaning is that the material is COMPRESSED or THICKENED and not necessarily “wrinkled”. Usually, metal thickness is also studied next to formability to determine if an imperfection exists or not. eg: material may show BLUE but actual thickening may be 0.1% of metal thickness or less which does not indicate a “wrinkle” or surface defect for non-skin panel products.

StampingSimulation.com Pty Ltd provides sheet metal forming simulation services using world class Autofom software.