The failure was exacerbated by a high level of residual stress in the eyebar.
There was substantial residual stress in the cartridge shells as a result of cold forming.
In extreme cases, residual stress can cause structural failure.
The pits also increase the components' surface area and leave behind residual stresses.
The difference is the residual stress in the edge and glass surface.
These methods create deep compressive residual stresses to increase component life.
If there is residual stress within the polymer, the piece will shrink when held at such a temperature.
"You get tremendous residual stress in a pipe that's subject to a welding process like that," the engineer said.
Castings may also have large residual stresses due to uneven cooling.
There are several techniques that are used to measure the residual stress.