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Service Life Prediction of Composite Structures through Fiber Testing.

ADA275661

Publication Date	1993
Personal Author	Morin, G. S.
Page Count	94
Abstract	Increasing the severity of the stress history of a structure reduces it's service life. Feasibility studies to increase the zero fuel weight of the P-3 Orion depend heavily on the resulting decrease in service life of the wing box and airframe. One option of extending the service life of existing aircraft is through the replacement or augmentation of critical structural members with composite materials. Since structural composites do not yet have adequate service life statistics, life predication must be through probability modeling. Such modeling can begin with experimental data on accelerated testing of fiber life under several sustained load levels. This data can be the basis for an appropriate strength-life model of the fiber which can in term be related to the strength-life model of the composite by the local-load sharing model. The local load sharing model captures the physical failure sequence of fiber failure within a composite. Such a strength-life model, when combined with structural analysis, can be used to predict an airframe's service life under the changed conditions associated with the zero fuel weight increase. Service Life, S-N Curve, Weibull, Maximum likelihood estimators break down rule.
Keywords	Aircraft Composite materials Probability Composite structures Fiber reinforced composites Life expectancy(Service life) Accelerated testing Airframes Augmentation Experimental data Feasibility studies Fibers Fuels Models Replacement Sequences Statistics Structural analysis Weight Wing boxes Wings Theses Stress analysis Computerized simulation Strength(Mechanics) Load distribution Failure(Mechanics) Weibull density functions Maximum likelihood estimation
Source Agency	Non Paid ADAS
NTIS Subject Category	51C - Aircraft 71F - Composite Materials 41K - Engineering Materials 72F - Statistical Analysis
Corporate Authors	Naval Postgraduate School, Monterey, CA.
Document Type	Thesis
Title Note	Master's thesis.
NTIS Issue Number	199411

Service Life Prediction of Composite Structures through Fiber Testing.

Service Life Prediction of Composite Structures through Fiber Testing.
ADA275661

Publication Date	1993
Personal Author	Morin, G. S.
Page Count	94
Abstract	Increasing the severity of the stress history of a structure reduces it's service life. Feasibility studies to increase the zero fuel weight of the P-3 Orion depend heavily on the resulting decrease in service life of the wing box and airframe. One option of extending the service life of existing aircraft is through the replacement or augmentation of critical structural members with composite materials. Since structural composites do not yet have adequate service life statistics, life predication must be through probability modeling. Such modeling can begin with experimental data on accelerated testing of fiber life under several sustained load levels. This data can be the basis for an appropriate strength-life model of the fiber which can in term be related to the strength-life model of the composite by the local-load sharing model. The local load sharing model captures the physical failure sequence of fiber failure within a composite. Such a strength-life model, when combined with structural analysis, can be used to predict an airframe's service life under the changed conditions associated with the zero fuel weight increase. Service Life, S-N Curve, Weibull, Maximum likelihood estimators break down rule.
Keywords	Aircraft Composite materials Probability Composite structures Fiber reinforced composites Life expectancy(Service life) Accelerated testing Airframes Augmentation Experimental data Feasibility studies Fibers Fuels Models Replacement Sequences Statistics Structural analysis Weight Wing boxes Wings Theses Stress analysis Computerized simulation Strength(Mechanics) Load distribution Failure(Mechanics) Weibull density functions Maximum likelihood estimation
Source Agency	Non Paid ADAS
NTIS Subject Category	51C - Aircraft 71F - Composite Materials 41K - Engineering Materials 72F - Statistical Analysis
Corporate Authors	Naval Postgraduate School, Monterey, CA.
Document Type	Thesis
Title Note	Master's thesis.
NTIS Issue Number	199411