نوع مقاله : پژوهشی
نویسندگان
تهران، دانشگاه علم و صنعت، دانشکده مهندسی مکانیک، قطب علمی مکانیک جامدات تجربی و دینامیک، آزمونگاه تحقیقاتی کامپوزیت، صندوق پستی 13114-16846
چکیده
کلیدواژهها
عنوان مقاله [English]
نویسندگان [English]
The mechanical properties of epoxy resin including tensile and flexural modulus, tensile and flexural strength for static conditions are currently studied. The frequency effect as significant parameter at room temperature is investigated and fatigue behavior of the epoxy resin in tension-tension loading conditions for different frequencies of 2, 3 and 5 Hz are obtained. The epoxy resin has been taken under flexural bending fatigue loading and fatigue life is investigated. The results of the experiments show the values of 2.5 and 3 GPa of tensile and flexural modules and 59.98 and 110.02 MPa of tensile and flexural strengths for the resin, respectively. To achieve a linear load-deflection relationship in a three-point bending experiment, a maximum allowable deflection of 5 mm is acquired. The relationship between the frequency and fatigue life shows higher frequency results in lower fatigue life. Loading with frequency of 2 Hz has provided 5.8 times more fatigue life compared with 5 Hz loading. For a tension-tension fatigue loading condition, the variation of tensile module of epoxy resin shows no noticeable change during the fatigue loading condition. This module decreases significantly only in the primary and failure cycles close to the fracture point. In further experiments, fatigue behavior of epoxy resin was tested under flexural bending fatigue loadings with controlled deflection at room temperature. Maximum applied normalized stresses versus the number of cycles to failure curve are illustrated and it can be performed in order to predict the number of cycles to failure for the resin in arbitrary applied normal stresses as well.
کلیدواژهها [English]
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