Application of the eigenstrain approach to predict the residual stress distribution in laser shock peened AA7050-T7451 samples

• Published in: Surface & coatings technology 2015-07, Vol.273, p.39-49
• Main Authors: Coratella, S., Sticchi, M., Toparli, M.B., Fitzpatrick, M.E., Kashaev, N.
• Format: Article
• Language: English
• Subjects: AA7050; Aircraft components; Alloys; Aluminum base alloys; Compressive properties; Computer simulation; Curved; Eigenstrain; Laser Shock Peening; Laser shock processing; Peening; Residual stress; Residual stress prediction
• ISSN: 0257-8972; 1879-3347
• DOI: 10.1016/j.surfcoat.2015.03.026

Laser Shock Peening allows the introduction of deep compressive residual stresses into metallic components. It is applicable to most metal alloys used for aerospace applications. The method is relatively expensive in application, and therefore development studies often rely heavily on Finite Element Modelling to simulate the entire process, with a high computational cost. A different approach has been used recently, the so-called eigenstrain approach. The present study looks at the feasibility of applying the eigenstrain method for prediction of the residual stress in a sample that contains curved surface features. The eigenstrain is determined from a simple geometry sample, and applied to the more complex geometry to predict the residual stress after Laser Shock Peening. In particular the prediction of residual stress at a curved edge, and for different values of material thickness, have been studied. The research has demonstrated that the eigenstrain approach gives promising results in predicting residual stresses when both the thickness and the geometry of the peened surface is altered. •Application of the eigenstrain theory was investigated in different geometries.•Where thickness increases, the eigenstrain accurately predicts the stresses.•On the curved edges, the eigenstrain theory shows limitations.