Tensile properties of carbon fiber/epoxy laminates at low and room temperatures
Krzysztof Majerski, Barbara Surowska, Jarosław Bieniaś
Quarterly No. 3, 2012 pages 182-185
DOI:
keywords: carbon fibre, laminates, tensile property
abstract Polymer composites based on carbon fibers are used in a large number of applications in the environment of low temperatures. The current use of such composites is not limited to support structures but carbon/epoxy materials are also used successfully as primary structures in aeronautic applications. The paper presents the tensile properties of a AS7J carbon/epoxy laminate at low and room temperatures. The composite prepreg system includes epoxy M12 resin as the matrix and unidirectional high-strength carbon fibers as reinforcement. Tensile tests were performed at room temperature (RT), 223 and 153 K using an MTS 322.31 testing machine equipped with an environmental chamber. The strain gauge Vishay CEA-06-125UT-350 was employed to measure the strain. The tensile modulus, strength and Poisson ratio at different temperatures were compared. The failure analysis of the samples was investigated by scanning electron microscopy (SEM). F The fracture morphology at the interface between the fiber and matrix was also observed. The results have shown that the mechanical properties depend on temperature. The tensile modulus of the AS7J carbon/epoxy laminate increased as the temperature decreased, however, the tensile strength showed a slight decrease at lower temperatures. The value of Poisson's ratio fell slightly when the temperature decreased. The failure analysis of the specimens indicates that the nature of the destruction of the samples is also dependent on temperature. Classic morphology damage known as high-energy damage was observed in samples tested at room temperature and a more complex type of damage occurred in the samples at the temperature of 153 K.