STP723: Effects of Proof Test on the Strength and Fatigue Life of a Unidirectional Composite

    Wang, ASD
    Professor of Applied Mechanics, billing professor of Mechanical Engineering, and graduate student, Drexel University, Philadelphia, Pa.

    Chou, PC
    Professor of Applied Mechanics, billing professor of Mechanical Engineering, and graduate student, Drexel University, Philadelphia, Pa.

    Alper, J
    Professor of Applied Mechanics, billing professor of Mechanical Engineering, and graduate student, Drexel University, Philadelphia, Pa.

    Pages: 17    Published: Jan 1981


    Abstract

    The effects of a static proof testing on the statistical distribution of the static strength and fatigue life of a unidirectional graphite-epoxy laminate (AS-3501-05) are investigated experimentally. Loading mode for both the static and fatigue tests is restricted to uniaxial tension in the fiber direction. Six-ply tension coupons with dimensions of 22.9 cm by 1.9 cm are used; and all tests are conducted using a closed-loop Instron tester, under room temperature (∼21°C) and ambient humidity (∼60% percent relative humidity) conditions. Test data are analyzed by means of a two-parameter Weibull distribution in conjunction with the maximum likelihood method for parameter estimation. Results show that proof testing can guarantee a minimum static strength, and to a lesser degree, the method can also assure a minimum fatigue life.

    Keywords:

    composite materials, fatigue (material), graphite-epoxy, proof test, statistical analysis, unidirectional laminates


    Paper ID: STP27617S

    Committee/Subcommittee: E08.05

    DOI: 10.1520/STP27617S


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