Imagine this: You are sitting on a plane getting ready to take off, and you see a mechanic working on the wing of the plane. The mechanic is making some last-minute checks when they accidentally drop a wrench on the wing that puts a sizable dent on the surface. It is instances like this that compression after impact (CAI) testing is done. After performing this type of test, a composite manufacturer can fully understand the structural effects that any impact would on a given material.

Performing a CAI test in accordance with ASTM D7137/7137M determines the residual strength of multi-directional composite laminate plates that have been subjected to quasi-static indentation. This particular test requires a CAI fixture that is designed in accordance to the standard.