On the physics of applying finite width and geometry correction factors in fatigue crack growth predictions of GLARE

In general, a finite width correction to stress intensity factor (SIF) is required in the fatigue crack growth. The finite width correction factor can be explained physically from the energy point of view. It is assumed that the finite width correction factor primarily constitutes an energy correction factor, i.e. it corrects the applied load for the work applied. To evaluate the finite width correction for FMLs, constant amplitude load fatigue crack growth tests were performed on monolithic aluminium 2024-T3 and the Fibre Metal Laminate GLARE containing 2024-T3 aluminium layers. The loads and displacements were recorded to quantify the total amount of work applied throughout each fatigue test. The crack length and delamination size were monitored by using digital image correlation technique to evaluate the dissipative energy. It appears that the Feddersen's and all other standard finite width correction significantly overestimates the effect for FMLs. The finite width correction to SIF for FMLs is small but cannot be neglected, and it is also greatly related to the Glare grades, stress ratio and stress level.Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Structural Integrity & CompositesAerospace Structures & Material