Crack propagation in an aluminum plate bonded to a glare panel: Case study

Resumo

© 2020, American Institute of Aeronautics and Astronautics Inc, AIAA. All rights reserved.Glare reinforcements have been adopted in the aeronautics industry to improve fatigue performance of structural components. Glare can be applied on early stages of the project’s design or used as temporary repairs, bonded on monolithic aluminum panels to improve crack retardation. In this work, experimental tests and verified numerical models are used to analyze the crack propagation in hybrid aeronautical structures. A Glare panel bonded to a monolithic aluminum plate with an initial crack, both with the same thickness, is tested under Mode I cyclic loading and fatigue crack propagation is measured. In order to optimize the reinforcement effect of Glare on monolithic aluminum structures, a parametric analysis is performed using verified numerical models, with different monolithic aluminum and Glare thicknesses ratio. The numerical results indicate that, for short cracks, a thinner Glare reinforcement results in a greater fatigue life. On the other hand, thicker Glare reinforcement leads to better results for long cracks. It is concluded that the damage tolerance requirements shall guide the definition of the ratio between plate and Glare thicknesses.