Experimental study of the effct of woven composites patch on crack propagation of AA5252 aluminum alloy sheets
Abstract:
Using composite patches to suppress the crack propagation is one of the effective methods to repair engineering structures. The aim of present research is to investigate the effect of patch geometry on the crack propagation behavior of a 5251 aluminium alloy sheet. For this purpose, epoxy resin/Kevlar fibers patch with two different geometry (rectangular and H shaped) was employed to reinforced the sheet. Araldite 2011 adhesive was used to bond the patch to the aluminium sheet. Tensile test was performed to determine force-displacement curves which were used to evaluate the crack propagation behavior. The results show that using composite patch provides higher tensile strength. Repairing the aluminium alloy sheet with epoxy resin/Kevlar fibers patch led to the enhancement of fracture toughness (about 53.9%). Moreover, displacement to fracture, force at the moment of crack growth initiation and fracture force was increased by increasing the patch area. Comparing the force-displacement curves for rectangular and H shaped patches indicate that crack growth was initiated at higher forces and higher displacement value for H shaped patch.