Comparis Analysis on National and American Standards for Flexural Property Test of Fiber-Reinforced Polymer Matrix Composites

The flexural property test standards of fiber-reinforced polymer matrix composites GB/T 1449-2005 and ASTM D7264/D7264M-15 were compared and analyzed from the aspects of application scope, principle, equipment requirements, span thickness ratio, specimen size and failure judgment. The flexural strength comparison test was carried out to Toray T300-3k fiber-reinforced epoxy resin composite according to these two standards. The results show that compared with GB/T 1449-2005, ASTM D7264/D7264M-15 is more reasonable and meticulous in the aspects of flexural property test span, bearing radius and failure judgment. GB/T 1449-2005 lacks failure judgment and the specified bearing size is small. The average bending strength measured according to the two standards is 927 MPa and 966 MPa, respectively, and the coefficient of variation is 3.60% and 3.78%, respectively. The lower coefficient of variation indicates that both methods have very stable test data, but the shorter span makes the bending strength measured according to GB/T 1449-2005 lower than that measured according to ASTM D7264/D7264M-15.