Patent ID: 6914215

Claim:
A method for quality control testing of a laser shock peening process of production workpieces, the method comprising the following steps: (a) laser shock peening surface of the production workpiece by firing a plurality of laser beam pulses from a laser shock peening system on the surface of the production workpiece and forming a plurality of corresponding plasmas, each one of the plasmas for each one of the pulses having a duration in which the plasma causes a region to form beneath the surface, the region having deep compressive residual stresses imparted by the laser shock peening process, (b) measuring at least one natural frequency for each of the laser beam pulses during a period of time during the duration of each corresponding one of the plasmas, (c) calculating natural frequency shifts from a baseline natural frequency for the measured natural frequencies for at least a portion of the laser beam pulses, and (d) using the natural frequency shifts for accepting or rejecting the workpiece with respect to pass or fail criteria for quality assurance of the laser shock peening process.