Environmental Durability Trial of Bonded Composite Repairs to Metallic Aircraft Structure

摘要

An agreement between DSTO and the US Air Force Research Laboratory (AFRL) was established as a part of a larger Aging Aircraft Project Agreement (PA). As a part of this agreement a large experimental program was organised to examine the long-term environmental durability of bonded composite repairs to metallic aircraft structure. An important aspect of the program was to examine the reliability and performance of current or recently developed surface treatments for metallic surfaces being repaired in field situations. The program involved the production of over 100 metal skinned honeycomb beam samples that wee each patched with boron composite doublers. The beam samples are now being cyclically loaded in four point bending rigs at the DSTO tropical test facility in Innisfail, northern Queensland. It was anticipated that cyclic loading of the beams would result in adhesive disbonding for samples where the surface treatments were known to be inferior on the basis of accelerated laboratory testing. The overall results were hoped to enable the durability of metal to adhesive bonds present in boron composite repairs to be assessed for conditions similar to those expected in aircraft operating environments. An additional outcome of the research was hoped to be the ability to correlate accelerated durability testing conducted in the laboratory with more realistic aging conditions expected in aircraft service.