DISBOND GROWTH ASSESSMENT FOR BONDED JOINTS AND PATCH REPAIRS OF PRIMARY AIRFRAME STRUCTURES

摘要

This paper develops a novel assessment approach of a generic patch repair specimen, namely the Double Overlap Tapered End Specimen (DOTES). The purpose is to analytically assess the applicability of a slow disbond growth approach for an adhesive joint under fatigue loading, and establish the required specimen parameters for experimental validation. Stress-strain based adhesive failure criterion and Virtual Crack Closure Technique (VCCT) are used to investigate the stability of the disbond as it progresses. The results indicated that the slow growth approach would be feasible even when a disbond crack grows to a significant length. Provided that a relationship between the fatigue crack growth rate and SERR value is determined through experiment, using the approaches described in this paper would enable a slow growth fatigue life prediction capability.