Determination of residual stresses in aluminum-alloy sheet material

A method has been developed for the determination of residual stresses in thin sheet material. Thin layers are removed by chemical etching, which induces an increasing curvature of the sheet. The initial distribution of the residual stress is derived from curvature measurements. Details of the etching procedures and the equations required for the calculations are presented. Results are given for as-rolled sheet material and for spot-peened material.