An analytical model for predicting fatigue crack arrest and growth behavior in metal plates strengthened with unbonded prestressed reinforcing strips

Fatigue crack arrest and life extension of metallic structures can be achieved by using prestressed strips for fatigue strengthening. However, the popularization of prestressed strengthening techniques has been limited by lack of versatile analytical methods. In this paper, an analytical method is developed for predicting the fatigue behavior of centrally cracked metal plates after being anchored with prestressed reinforcing strips, based on linear elastic fracture mechanics and the superposition method of stress intensity factors. The force transfer between reinforcing strips and metal cracked plates is modeled using the displacement compatibility principle. The finite-width correction factor for centrally cracked metal plates subjected to four-point concentrated forces is derived, allowing the model to analyze the effect of different anchorage locations on the effectiveness of strengthening. The analytical model is validated through experimental data and finite element analysis. The results show that the model is highly accurate and can be used to analyze how different anchorage locations affect fatigue reinforcement.