KAJI EKSPERIMENTAL DAN NUMERIK TENTAN G FAKTOR KETANGGUHAN RETAK MODUS I DAN II PADA LAMINATE KARBON/EPOXY SERAT TERANYAM
Abstract
This paper presents experimental and numerical analysis on the inuence of crack orientations to the fracture toughness of mode I and mode II for woven type carbon/epoxy four ply laminate. The experimental procedure is carried out through off axis tensile test (ASTM D 3039-76) with nine variation of crack orientations i.e. 5, 10, 15, 30, 45 65, 75, 80, and 90. Three rail shear test (ASTM D 4255-83) is utilized for zero degree crack orientation. The stress and strain contours around crack tips are obtained numerically using the finite element method. Numerical and experimental results of the mode I (KI) and mode II (KII) fracture thoughness are presented in graphical form as a function of crack directions. Adopting Wu's(11) Criteria for unidirectional lamina and Hahn's[6] Criteria for general anisotropic lamina, a new mixed mode fracture toughness criteria is developed for woven fiber matrix laminate.
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