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Reliability, Risk and Cost Trade-Offs for Composite DesignsRisk and cost trade-offs have been simulated using a probabilistic method. The probabilistic method accounts for all naturally-occurring uncertainties including those in constituent material properties, fabrication variables, structure geometry and loading conditions. The probability density function of first buckling load for a set of uncertain variables is computed. The probabilistic sensitivity factors of uncertain variables to the first buckling load is calculated. The reliability-based cost for a composite fuselage panel is defined and minimized with respect to requisite design parameters. The optimization is achieved by solving a system of nonlinear algebraic equations whose coefficients are functions of probabilistic sensitivity factors. With optimum design parameters such as the mean and coefficient of variation (representing range of scatter) of uncertain variables, the most efficient and economical manufacturing procedure can be selected. In this paper, optimum values of the requisite design parameters for a predetermined cost due to failure occurrence are computationally determined. The results for the fuselage panel analysis show that the higher the cost due to failure occurrence, the smaller the optimum coefficient of variation of fiber modulus (design parameter) in longitudinal direction.
Document ID
Document Type
Conference Paper
Shiao, Michael C. (NYMA, Inc. Brook Park, OH United States)
Singhal, Surendra N. (NYMA, Inc. Brook Park, OH United States)
Chamis, Christos C. (NASA Lewis Research Center Cleveland, OH United States)
Date Acquired
September 6, 2013
Publication Date
December 1, 1996
Subject Category
Structural Mechanics
Report/Patent Number
NAS 1.15:107390
Meeting Information
International Symposium and Exhibition(Anaheim, CA)
Funding Number(s)
PROJECT: RTOP 505-62-10
Distribution Limits
Work of the US Gov. Public Use Permitted.

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NameType 19970010117.pdf STI