Fatigue Crack Growth Analysis Using Surrogate Modelling Techniques for Structural Problems

This paper addresses the polynomial-based response surface models for fatigue crack growth problems. The fatigue crack growth behaviour of critical pin-loaded lug with through-the-thickness crack at a hole was analysed using finite-element (FE) tools. The stress intensity factor (SIF) and fatigue crack growth life for the incremental crack length of the attachment lug was predicted using Virtual Crack Closure Technique (VCCT) approach and crack growth laws, respectively. The polynomial-based surrogate model was built using the FE characterisation of the relationship between various crack parameters such as crack size, load applied, thickness, stress intensity factor and fatigue crack growth life. Then, using the developed model, stress intensity factors and fatigue crack growth life for various parameters were obtained without the help of FE tools. Hence, the computation cost of using finite-element tools was reduced.