Mathematical Model and Verification of Residual Stress Induced by Water Jet Peening

Abstract

The water jet peening (WJP) technology can induce compressive residual stress (RS) in metal surfaces and, thus, improve the fatigue life of components. In this paper, a mathematical model is proposed for calculating the RS induced by WJP. To validate the proposed mathematical model, experimental and finite element simulation verifications were carried out on Al6061-T6. The distribution of RS along the depth direction, the maximum compressive RS, and the depth of the compressive RS layer were also investigated based on the mathematical model. Results showed that the error of maximum compressive RS between the mathematical model and experiment was within 9% under a jet pressure of 60 MPa, and the error of depth of the compressive RS layer between the mathematical model and experiment was within 13% under a jet diameter of 0.3 mm. Hence, the mathematical model is reliable and accurate. The maximum compressive RS increases with the increase in jet pressure, and the depth of the compressive RS layer approximately linearly increases with the increase in jet diameter.

Keywords

• water jet peening
• residual stress
• mathematical model
• finite element simulation
• aluminium alloys