Tensile, compressive and shear properties of unidirectional glass/epoxy composites subjected to mechanical loading and low temperature services

299-309Composite materials are subjected to low temperatures in service and this has induced the need for a proper knowledge of low temperature behavior of composites. Most of the research in this field is focused on applying different types of loading and laminated configurations. This paper discusses the experimental study on the tensile, compressive and in-plane shear behavior of unidirectional (UD) glass fiber reinforced polymeric composite under static and low temperature loading conditions. Since UD composite is the basic building block of a composite structure and can be used to make general laminates. In order to fully characterize UD laminate, several experimental tests are performed using an environmental test chamber and a universal testing machine. Thermo-mechanical loads are applied to glass/epoxy unidirectional laminates at room temperature (25°C), -20°C and -60°C. The results of the present study indicate that low temperatures have a significant effect on composite failure mode. It is also found that the strength and modulus of UD composites both increased with decreasing the temperature in all cases including tensile, compressive and shear loads. On the other hand, the results show that strain to failure decreased by decreasing the temperature

Dynamic failure behavior of glass/epoxy composites under low temperature using Charpy impact test method

211-220This paper demonstrates results of an experimental study on glass/epoxy laminated composites subjected to low velocity impact at energy levels equal to 10, 15 and 30 J under variable temperatures in the range of -30°C to 23°C. The configuration of specimens is quasi-isotropic. The low temperature and its influence on the maximum absorbed energy, elastic energy, crack length and delamination are highlighted. Also, the effects of geometry index (span-to-depth) and notch orientation are studied. Failure mechanisms of specimens are examined using microscopic examinations. Results indicate that impact performance of these composites is affected over the range of temperature considered. Failure mechanism is changed from matrix cracking at room temperature to delamination and fiber breakage at low temperatures