Interfacial Crack Arrest in Sandwich Panels with Embedded Crack Stoppers Subjected to Fatigue Loading

Abstract

Abstract:A novel crack arresting device has been implemented in sandwich panels and tested using a special rig to apply out-of-plane loading on the sandwich panel face-sheets. Fatigue crack propagation was induced in the face-core interface of the sandwich panels which met the crack arrester. The effect of the embedded crack arresters was evaluated in terms of the achieved enhancement of the damage tolerance of the tested sandwich panels. A finite element (FE) model of the experimental setup was used for predicting propagation rates and direction of the crack growth. The FE simulation was based on the adoption of linear fracture mechanics and a fatigue propagation law (i.e. Paris law) to predict the residual fatigue life-time and behaviour of the test specimens. Finally, a comparison between the experimental results and the numerical simulations was made to validate the numerical predictions as well as the overall performance of the crack arresters. ABSTRACT:A novel crack arresting device has been implemented in sandwich panels and tested using a special rig to apply out-ofplane loading on the sandwich panel face-sheets. Fatigue crack propagation was induced in the face-core interface of the sandwich panels which met the crack arrester. The effect of the embedded crack arresters was evaluated in terms of the achieved enhancement of the damage tolerance of the tested sandwich panels. A finite element (FE) model of the experimental setup was used for predicting propagation rates and direction of the crack growth. The FE simulation was based on the adoption of linear fracture mechanics and a fatigue propagation law (i.e. Paris law) to predict the residual fatigue life-time and behaviour of the test specimens. Finally, a comparison between the experimental results and the numerical simulations was made to validate the numerical predictions as well as the overall performance of the crack arresters.

Mechanical behaviour of fabric-reinforced plastic sandwich structures: A state-of-the-art review

“…Several studies were conducted on the development of numerical models that can be used in the validation of the macro-and meso-damage of FRPSS. These studies have investigated the fracture characteristics, [118][119][120] flexural properties, 60,121,122 and compression behavior 123 of such structures with two and threedimensional models. Farshidi et al 16 developed a 2D FEA model of a disbonded honeycomb-core sandwich structure using the crack surface displacement extrapolation method to investigate the energy release rate and mode-mixity of the panels.…”