Effects of patch layer and loading frequency on fatigue fracture behavior of aluminum plate repaired with a boron/epoxy composite patch

Abstract

In this study, 6.125 mm cracked Al 7075-T6 plates with different patch layers of boron/epoxy composite have been fatigue tested. By using analytical and experimental methods, the variation of critical parameters in fracture mechanics, such as stress intensity factor (SIF), potential energy (PE) and energy release rate (J * ), with patch layers were studied. According to the results of energy and driving force approaches, it was shown that both theories had good consistency using more ply numbers to repair cracked substrates. It was suggested that to investigate the effect of the patch layer on the air stream around the aircraft structure, in addition to fracture mechanics analysis, using a fluid dynamics simulation would be very helpful.

Effect of Interface Structure on Mechanical Properties of Advanced Composite Materials

“…To obtain sufficient shear strength for adhesive bonding, the bonding area should be thoroughly cleaned and abraded before the preparation of bonding patches. The procedures for aluminum alloy substrate preparation were given in [ 58 , 59 ].…”

Comparison of Repair Methods for Cracked Titanium Alloy Aircraft Structures with Single-Sided Adhesively Bonded Composite Patches

“…Following this, many scholars conducted numerous studies on the repair ingredients in the repair system. In terms of patch materials, glass-epoxy, carbon-epoxy, boron-epoxy, graphite-epoxy, aramidepoxy as well as their hybrid patches were employed for the repair of cracked aluminum alloy (Al-alloy) components [7][8][9][10][11]. Among these, carbon fiber composites exhibited a higher elastic modulus and tensile strength, while the incorporation of aramid fiber layers effectively improved the bending behaviors of carbon fiber patches.…”