Non-uniform residual stress measurement in Aluminum 7075-T6 by the ring-core method and integral technique

To measure the non-uniform residual stress in an extruded commercial aluminum 7075T6 specimen, the ring-core method and the integral computational technique have been implemented. The necessary calibration coefficients to measure the non-uniform residual stresses by the ring-core method and integral technique have been calculated by the FE analysis. The calculated calibration coefficients have been validated by separate 3D FE model. To validate the calibration coefficients the pure bending process has been considered. The results have been indicated that the measured residual stress by the ring-core method and integral technique was close to the analytical value of the residual stresses in pure bending condition. This result confirms the effectiveness of the ring-core method and integral technique to measure the non-uniform residual stresses in the depth direction. The residual stresses in an extruded Al 7075T6 have been measured experimentally and the results have been indicated compressive residual stresses from the surface to depth 4mm.