Strength of Notched Uni-directional Composites with Various Fiber Angles (2nd Report, Strength Evaluation for the Specimen with Various Fiber Angles from that with 90 deg Fiber Angle)

摘要

The fracture criterion for notched uni-directional composites is discussed in this paper. The tensile tests of specimens are carried out with various fiber angles and various shaped notches. The fracture origins are carefully observed and the elastic analysis shows that the initiation of the fracture is dependens on the transverse strain to the fiber direction. The maximum strain criterion should be applied to the fracture. Then the criterion is extended to consider the relation between the fracture strength of speciment with various fiber angles. The extended criterion is based on the local equivalent elastic fields with Stress Intensity Factor. It is confirmed from the experimental data of CFRP that the criterion can be applied to the strength evaluation of the real structure.