Prediction of long-term fatigue strength of quasi-isotropic CFRP laminates with a hole under compressive loading

Abstract

This paper deals with the constituent-based characterization of long-term strength of CFRP structure components with the combined method (MMF/ATM method) of micromechanics of failure (MMF) and the accelerated testing methodology (ATM) developed by Tsai, Christensen, Miyano and others. The time-temperature dependent master curves of MMF/ATM critical parameters were constructed by tensile and compressive tests under static and fatigue loadings for the longitudinal and transverse directions of unidirectional CFRP under various temperatures based on the time-temperature superposition principle which holds for the viscoelastic behavior of matrix resin. These master curves can be used for predicting the fatigue strength of composite structures with multi-directional CFRP laminates at any time to failure, temperature and number of cycles to failure. The applicability of MMF/ATM method was experimentally confirmed by prediction of the open hole compression static and fatigue strength of the quasi-isotropic CFRP laminates. ©Freund Publishing House Ltd.