Crack growth analysis of fiber metal laminates stiffened panels

icaf2023 Tracking Number 146

The use of fiber metal laminates stiffened panels for aerospace application has been largely increasing due to its low crack propagation rate and excellent residual strength behavior. In order to compare the traditional built up aluminum constructed stiffened panels and fiber metal laminates materials under the context of damage tolerance, two stiffened panels are design, tested and compared against finite element models: (1) aluminum skin with riveted stringers and (2) fiber metal laminate skin with bonded stringers. The two panels exhibited significantly different results, with the fiber metal laminate stiffened panel having the best response in both crack propagation and residual stress. With the objective of obtaining an accurate analysis tools for these two panels, filling a gap of available commercial softwares, detailed Finite Element Models are built aiming the use of Virtual Crack Closure Technique to obtain Stress Intensity Factors, taking into account the delamination phenomenon during crack propagation on fiber metal laminates materials. Numerical results show that the proposed technique can reach good correlation and it is observed that the chosen delamination shape largely dictates crack growth behavior on the fiber metal laminates stiffened panel.