Growth Characterisation of Fatigue Cracks Repaired with Adhesively Bonded Boron/Epoxy Patches

摘要

This study is aimed at characterising crackgrowth in patched panels under constant amplitude loading.The variables evaluated are: a) patch disbond size, b) appliedstress, C) patch thickness, d) R ratio and e)temperature. Foruse with the model a simple Paris-typs crack growthrelationship is assumed between da/dN and #DELTA#K for thepatched crack. The patching system studied consists of pre-cracked 2024 T3 aluminium test panels (~3 mm thick) repairedwith boron/epoxy patches, bonded with adhesive FM 73.Generally, Rose's model for estimation of #DELTA#K inpatching situations appears capable of predicting crack growthbehaviour for this simple patching configuration quite well, butseveral issues remain to be resolved regarding the effect of Rratio and temperature.