考虑小裂纹特性的裂纹扩展数值分析方法及实验验证

In order to conduct a comprehensive damage tolerance analysis of critical engineering components，it is particularly important to develop a numerical analysis method for fatigue crack growth that can consider the small crack stage. Accounting for the characteristics of the small crack growth behaviour of nickel-based powder superalloys，a crack growth rate model applicable to both small crack and long crack based on the Paris formula was proposed. At the same time，considering the engineering application，this model was inserted into the Franc 3D software through the python extensions to construct a numerical analysis method that could analyse the fatigue crack growth of the actual engineering structure such as the aero-engine turbine disk. Numerical analysis of crack growth was carried out on the FGH96 alloy specimen with initial defects. The numerical calculation results are in good agreement with the experimental results，indicating that the method can sufficiently consider the characteristics of crack growth behaviour at the small crack stage，and is suitable for analysing the whole process of fatigue crack growth in engineering structures.