Influence of stiffener on fracture parameter and fatigue crack growth life of a finite aluminium alloy plate

The present paper discusses the methodology for prediction of fracture parameter, fatigue crack growth life (FC) and inspection interval (II) considering the stiffener effect using Afgrow software of NASGRO crack growth model. Based on numerically predicted normalised stress intensity factor (β) using finite element method (FEM), correction factor (C.F.) in β of un-stiffened panel/plate is introduced to account for the stiffener effect. The β of stiffened plate is further used for prediction of fatigue crack growth life (FC) and II. The fracture parameters of stiffened panel for different crack lengths, stiffener area, and stiffener offset using FEM are predicted, which is further used for estimation of FC and II. The typical numerical prediction of fracture parameter using finite element method and FC with incorporation of C.F. using Afgrow software is compared with published experimental results and analytical prediction which show good conformity.