Paper number 258
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TIME AND TEMPERATURE DEPENDENCE OF STATIC, CREEP AND FATIGUE BEHAVIOR FOR CF/EPOXY STRANDS |
Masayuki Nakada1, Yasushi Miyano1, Ryosuke Nakamae1, and Rokuro Muki2
1 Materials System Research Laboratory, Kanazawa Institute of Technology,
Yatsukaho, Matto, Ishikawa 924-0838, Japan
2 Civil & Environmental Engineering Department, University of California at Los Angeles,
Los Angeles, CA 90095-1593, U.S.A.
| Summary | A prediction method of fatigue strength under an arbitrary frequency, temperature, and stress ratio for polymer composites was proposed by measuring the constant-strain-rate (CSR) strength at various strain-rates and temperatures and the fatigue strength at a single frequency and various temperatures. This method is based upon the four hypotheses: (A) same failure process under constant strain-rate (CSR), creep, and fatigue loadings, (B) same time-temperature superposition principle for all failure strengths, (C) linear cumulative damage law for monotonic loading, and (D) linear dependence of fatigue strength upon stress ratio. Tensile CSR, creep, and fatigue tests of epoxy resin impregnated carbon fiber strands as used for unidirectional CFRP at various loading rates, frequencies, and temperatures were performed. Experimental verification of the prediction method is discussed for the tensile fatigue strength of this strand by using these results. |
Keywords | Carbon Fiber Reinforced Plastics, Fatigue, Life Prediction, Time-Temperature Dependent Properties |