Prediction of Tensile Fatigue Life for Unidirectional CFRP

• Published in: Journal of composite materials 2000-04, Vol.34 (7), p.538-550
• Main Authors: Miyano, Yasushi, Nakada, Masayuki, Kudoh, Hiroshi, Muki, Rokuro
• Format: Article
• Language: English
• Subjects: Applied sciences; Composites; Exact sciences and technology; Forms of application and semi-finished materials; Fracture mechanics (crack, fatigue, damage...); Fracture mechanics, fatigue and cracks; Fundamental areas of phenomenology (including applications); Physics; Polymer industry, paints, wood; Solid mechanics; Structural and continuum mechanics; Technology of polymers
• ISSN: 0021-9983; 1530-793X
• DOI: 10.1177/002199830003400701

Tensile fatigue strength in unidirectional CFRP depends on time and temperature as well as number of cycles. A prediction method of fatigue strength proposed [14] for polymer composites meeting certain conditions and confirmed for flexural fatigue strength of satin-woven CFRP laminates is applied to the tensile fatigue life of unidirectional CFRP. The method is based upon the four hypotheses: (A) same failure mechanisms for constant strain-rate (CSR), creep, and fatigue failure, (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. Data are provided for tensile CSR, creep, and fatigue tests at various temperatures in the longitudinal direction of unidirectional CFRP. Experimental verification of the prediction method for the tensile fatigue strength of the unidirectional CFRP is presented.