Discussion on FRP Design Properties Based on Flexural Tests (ASTM D-790) and Tensile Tests (ASTM D-638)

摘要

Tensile and flexural test results on the same laminate can have significant difference with the reported flexural strength being up to 100percent greater than the tensile strength using the standard ASTM reporting methods. Taken at face value, these results can lead to non conservative designs. The flexural test method is much simpler and less expensive, but must be used with a clear understanding of how they were computed and with sound engineering judgement since the flexural strength is calculated with linear bending theory at failure loads that are usually in the non linear range. This is significnat since the general accepted design practice is to use linear theory in the design of FRP equipment. Manufactures reporting this value should thus have a clear understanding of the difference between the reported results for flexural strength and the required design strength.