ADVANCED DAMAGE TOLERANCE AND RISK ASSESSMENT METHODOLOGY AND TOOL FOR AIRCRAFT STRUCTURES CONTAINING MSD/MED

摘要

This paper presents results from NRC'sdevelopment of advanced damage toleranceanalysis (DTA) and risk assessment methodsand tools for aircraft structures, includingbuild-up structures containing multi-site fatiguedamage (MSD) and multi-element damage(MED), to support the Canadian Forces (CF)aircraft structural life cycle management. TheDTA methods developed include new closedformsolutions and generic finite element (FE)based tools to calculate the stress intensityfactor (SIF) and the β-solutions for build-upstructural configurations. To facilitate the riskassessment, an in-house crack growth analysisprogram, CanGROW, was developed tosimultaneously grow multiple cracks.Guidelines were established to calculate theresidual strength of MSD/MED structures usingglobal and/or local FE models, consideringload redistribution among adjacent components.For the MSD risk analysis, an efficient MonteCarlo simulation technique was developed todetermine the crack size distributions atdifferent inspection intervals, which were thenused in NRC's risk analysis code ProDTA tocalculate the single flight hour probability offailure. Case studies on critical locations of theCC-130 centre wing structure are presented todemonstrate the capability of the developedmethods and tools.