Abstract
In this paper, the fatigue crack propagation model of the metal structure is studied, and a new crack propagation rate model is proposed. Compared with the traditional method, only the nominal applied stress and the critical fracture stress are considered in the new method, and the new one is much easier and more efficient. By analyzing the 2024-T351 and 7075-T6 aluminum alloy materials test data, the new model is validated and the results are compared with the classical method of crack propagation. The result shows the new model has a similar trend with the existing crack propagation curve, and provides a better description for the low rate and high rate area, it also shows a strongly practicability.