In order to more accurately predict the fatigue crack propagation behavior of titanium alloy TC4 under cyclic load

a new prediction model based on peridynamics theory was proposed.Within a finite near-field radius

a material point damage model was constructed to simulate the initiation and propagation of cracks.By establishing the plastic deformation damage model of the"bond"

the mechanism of fatigue crack initiation and propagation was deeply analyzed in this study.In order to improve the prediction efficiency and stability of the model

the critical damage factor of material point was introduced

and an improved adaptive dynamic relaxation method is adopted.The static solution can be obtained in each loading cycle

and the reliability of the model was further verified by the convergence analysis of the crack propagation results under different loading conditions.The experimental results show that the fatigue crack growth prediction model based on peridynamics theory can accurately predict the crack initiation location and crack growth rate without relying on additional crack growth criteria.In addition

the fatigue life predicted by the model is in good agreement with the experimental data

which proves the validity and practicability of the model in predicting fatigue crack growth of titanium alloy materials.