You can measure the major strain, minor strain, and thickness strain in the formed part, but what to you compare those values against to say if you have a good, robust stamping? The strain values that mark the forming limit is called the forming limit curve (FLC).
The shape and placement of the forming limit curve for low carbon steels have been known for decades thanks to the pioneering work of Dr. Stuart Keeler. All you need are the sheet metal thickness and strain hardening exponent (also known as the n-value).
But what about different types of sheet metal?
Unfortunately, it’s not as simple. Both the shape and the placement of the FLC must be determined through detailed testing.
Fortunately, Engineering Quality Solutions has both the experience and equipment to do this testing.
We’ve developed forming limit curves for sheet aluminum, zirconium, nickel, brass, and titanium alloys, as well as numerous stainless steel and Advanced High Strength Steel (AHSS) grades.
Let us know how we can help solve your challenges!