含开孔与含裂缝的复合材料层压板拉伸剩余强度评估OA

Experiments on about 200 composite laminates with four typical lay-ups,two kinds of damage,and four damage sizes were conducted to investigate the residual strength of composite laminates with open hole or crack.The research indicates that the residual strength of two composite laminates with open hole and crack are equal with same lay-ups and same widths of laminates when the opening diameter is equal to the crack width.Little cracks and delamination appear earlier at the root of crack during the loading process,the stress is redistributed near the root of crack,the stress concentration reduces.The method based on fiber breakage in damage zone criterion,classical laminate theory and complex variable function theory can be used to predict the residual strength of two composite laminates with open hole,the method can also be used for laminate with crack when the crack is equivalent to an open hole,the calculated results are in good agreement with the experimental results.