THE SIGNIFICANCE OF LAMINAR CORROSION DEFECTS IN AIRCRAFT

摘要

Laminar corrosion defects, such asrnintergranular penetrations and stress corrosionrncracks, are common in ageing aircraft. Theserndefects are most commonly found in extrudedrnand rolled sections made from high strengthrnaluminium alloys; typical examples includernwing and tailplane spar caps in widespread usernin ageing aircraft. They present a significantrnproblem in that the assessment of theirrnsignificance is difficult, not only because theirrnorientation (most commonly parallel to therndirection of applied stress) makes analysisrndifficult using conventional stress analysisrntechniques, but because of the inherentrnvariability of the laminar cracking process. Thernpaper summarises progress in AMRL researchrnwhich is investigating analytical andrnexperimental approaches to laminarrndefect/fatigue interactions.