Determination of the Internal Stress-Strain State of Aluminium Alloy Sheet Welded by FSW or Laser Technology by Means of Bi-Dimensional Wavelet Transform

After a processing such as a welding process, a lamination process or other types of plasticization, residual stress is that which remains in a body that is stationary and at equilibrium with its surroundings. Actually the industry demands fast and non-destructive characterization methods for continuous control of all products. Today, especially in the aviation industry the residual stress analysis is made by destructive methods. The present study, by involving thermal images detected trough infrared camera and the technique of Wavelet Transform, achieves important results in the non-destructive control systems. In this paper, through a technical and non-destructive method, the induced residual stress-strain state into sheet welded by Friction Stir Welding (FSW) or laser technology are analysed.