Application of Bonded Composite Repair Technology to Civil Aircraft — B747 Demonstration Programme

Abstract

As part of a demonstration program nine bonded‐composite doublers were applied to a Boeing 747–300 aircraft in service with Qantas Airways Limited. The aim was to demonstrate the environmental durability of this type of repair, and thus the doublers were not applied to any damaged locations. This paper describes the location of the doublers, the procedures used to apply them and their status after more than two years of senvice,

Bonded Composite Patch Repairs on Cracked Aluminum Plates: Theory, Modeling and Experiments

“…Composite patches, bonded on cracked or corroded metallic aircraft structures, have shown to be a highly cost effective method for extending the service life and maintaining high structural efficiency (Baker & Jones, 1988;Baker, 1993;Molent et al, 1989;Baker et al, 1984;Torkington, 1991;Bartholomeus, 1991). Damage tolerant and fail-safe design of aircraft, aerospace and civil structures requires a substantial amount of inspection and defects-monitoring at regular intervals.…”

Bonded composite repair structures multiple site damage analysis

“…Trapped at the interface, moisture turns into ice in flight, loading and propagating interfacial defects that grow into interfacial cracks. Nevertheless, successful patch repairs have been demonstrated for commercial aircrafts (Rarthlomeusz et al , 1993; Roach and Rackow, 2007).…”

“…Patch debonding can also be induced by environmental effects, where moisture substantially reduces adhesion (Waters and Volinsky, 2006). (Rarthlomeusz et al, 1993;Roach and Rackow, 2007).…”

Designing for damage-tolerant composite repairs

“…This concept forms the basis of the externally bonded composite patch described in [2,6]. In this case the maximum (highest) stresses in the adhesive occur when the cracks emanating from each fastener hole have all linked.…”