The hole is drilled in the center of the strain gage grids. The average residual stress occurring over the depth of the drilled hole can be calculated from the strain relaxations. An established method standardized by ASTM Procedure E837. Customized strain gages. Highly sensitive to position and shape of drilled hole.
Residual stresses determined are the average over the depth of drilled hole.
Incremental technique offers qualitative results only. Cast iron piping. Forged nickel base alloy disk components. Welded titanium pipes. Dual phase stainless steel rollers.