STATISTICS FOR THE TIME DEPENDENT FAILURE OF KEVLAR-49/EPOXY COMPOSITES: MICROMECHANICAL MODELING AND DATA INTERPRETATION

ABSTRACT In this paper we present some new data on the strength and stress-rupture of Kevlar-49 fibers, fiber/epoxy strands and pressure vessels, and consolidate data obtained at LLNL over the past 10 years. We interpret this data using recent theoretical results from a micromechanical model of the statistical failure process, and gain some understanding of the roles of the epoxy matrix and ultraviolet radiation on long term lifetime.

[1]  J. M. Lifshitz,et al.  Time-dependent longitudinal strength of unidirectional fibrous composites , 1970 .

[2]  D. Carlsson,et al.  Photodegradation of aramids. I. Irradiation in the absence of oxygen , 1978 .

[3]  B. D. Coleman.  Application of the theory of absolute reaction rates to the creep failure of polymeric filaments , 1956 .

[4]  T. Chiao,et al.  Room-temperature-curable epoxy for advanced fiber composites , 1973 .

[5]  Luke Tierney,et al.  Asymptotic bounds on the time to fatigue failure of bundles of fibers under local load sharing , 1982, Advances in Applied Probability.

[6]  M. Northolt.  Tensile deformation of poly(p-phenylene terephthalamide) fibres, an experimental and theoretical analysis , 1980 .

[7]  B. D. Coleman,et al.  The Interpretation of Creep Failure in Textile Fibers as a Rate Process , 1957 .

[8]  S. L. Phoenix,et al.  Lower-tail approximations for the probability of failure of three-dimensional fibrous composites with hexagonal geometry , 1983, Proceedings of the Royal Society of London. A. Mathematical and Physical Sciences.

[9]  Fp Gerstle,et al.  Prediction of Long-Term Failure in Kevlar 49 Composites , 1983 .

[10]  J. Hedgepeth.  Stress Concentrations in Filamentary Structures , 1961 .

[11]  Stress-Rupture Behavior of Strands of an Organic Fiber/Epoxy Matrix , 1974 .

[12]  L. Penn,et al.  Physicochemical properties of kevlar 49 fiber , 1979 .

[13]  S. Leigh Phoenix,et al.  Stochastic strength and fatigue of fiber bundles , 1978, International Journal of Fracture.

[14]  C. Chiao,et al.  Experimental Verification of an Accelerated Test for Predicting the Lifetime of Organic Fiber Composites , 1977 .

[15]  H. Hahn.  LONG-TERM BEHAVIOR OF COMPOSITE MATERIALS , 1980 .

[16]  D. J. Johnson,et al.  Supramolecular structure of a high‐modulus polyaromatic fiber (Kevlar 49) , 1977 .

[17]  Bernard D. Coleman,et al.  Statistics and Time Dependence of Mechanical Breakdown in Fibers , 1958 .