The analytical and experimental research on strength prediction of composite laminate with various surface notches were carried out. The strength was predicted analytically by applying classical laminate theory and measured experimentally from the first failure load in load-displacement curve. TBE(tetrabromoethane)-enhanced X-ray radiography, ultrasonic C-scan and photomicrograph were used to observe the matrix cracking and delamination. Three types of notch shapes were taken for experiments: center notch, extensive notch, shifted notch.
During the static failure process, matrix crack and delamination were observed at the notch root and the delamination of surface plies was observed at notch tips. The surface buckling of the delaminated surface plies was observed at the vicinity of notch tips prior to failure. The damage zone of extensive notch before failure was much larger than that of center notch. In case of the small size damage zone, the strength predicted by analysis showed good agreement with experimental results.
