New test approach to determine the transverse tensile strength of CFRP with regard to the size effect

The subject of this work is the investigation of the size effect on transverse strength of CFRP. A new test approach uses the remaining parts of already tested specimens for a second transverse tensile test. With this method it is analysed, whether first failure is dominated by the most critical flaw inside the material or at a load that is equivalent to the maximum tensile strength of the matrix. Thickness of the specimens is varied to study the influence of specimen volume on transverse tensile strength. Test results show that strength follows the trend of defect distribution with increasing strength for decreasing volume. Second failure strength is higher than first failure strength, showing that first failure occurs at the most critical defect and gives no evidence of the maximum transverse tensile strength of the material. Stress at second failure showed less scatter, proving good applicability of the proposed test method.