Comparison of out-of-plane tensile strengths of aligned CFRP obtained by 3-point bending and direct loading tests

In order to propose a simple and effective test method for the out-of-plane tensile strength of laminated carbon fiber reinforced plastics (CFRPs), 3-point bending tests using an aligned CFRP with the span direction coinciding with through-the-thickness direction were performed, and the results were compared with those obtained by the direct loading test proposed by the authors. Weibull statistics were applied to evaluate the size and stress distribution effects on both results. The out-of-plane tensile strengths obtained by both tests were found to be consistent. Thus the 3-point bending test was recommended as a standard test method to evaluate the out-of-plane tensile strength of CFRPs from the perspectives of ease of preparation of the specimen and the simple procedure to derive the strength.