
Accession Number : ADA018745
Title : Reliability and Risk Assessment Methods for Redundant Structures.
Descriptive Note : Final rept. Jun 72May 74,
Corporate Author : MASSACHUSETTS INST OF TECH CAMBRIDGE AEROELASTIC AND STRUCTURES RESEARCH LAB
Personal Author(s) : Orringer,O. ; McCarthy,J. F. ; Peterson,R. M. ; Seppanen,K. J.
Report Date : OCT 1975
Pagination or Media Count : 219
Abstract : This report summarizes developments of new reliability analysis methods resulting from research under Air Force Contract F3361570C1131. The historical background of risk assessment activities concerning the USAF fleet is reviewed and the flawgrowth and wearout approaches to material behavior are discussed to place the present work in perspective. A new definition of two categories of risk assessment probability calculation is proposed. The second category, which estimates risk due to strength degradation in an aging structure, is shown to require accounting for mechanical redundancy if accurate assessments are to be made. A new probability modelling procedure is presented. The new procedure accounts for mechanical redundancy by combining a new generalization of Daniels' fiber bundle theory with matrix structural analysis methods. Several example analyses are presented. The results of some related preliminary investigations on the effects of complexity in components and application of redundant models to timetofailure calculations are discussed. (Author)
Descriptors : *Reliability, *Redundant components, *Structural members, *Airframes, Structures, Risk, Failure(Mechanics), Assessment, Probability density functions, Strength(Mechanics), Degradation, Aging(Materials), Mathematical models, Safety, Fatigue(Mechanics), Life expectancy, Wear, Defects(Materials), Crack propagation, Overload, Loads(Forces), Probability, Wings, SKin(Structural), Jet fighters, Jet bombers
Subject Categories : Bombers
Attack and Fighter Aircraft
Mfg & Industrial Eng & Control of Product Sys
Distribution Statement : APPROVED FOR PUBLIC RELEASE