Suggested Modifications of the ASTM D2344-16 Short-Beam Shear Test Method to Be Applied to Fiber Metal Laminates

摘要

ASTM D2344/D2344M-16, Standard Test Method for Short-Beam Strength of Polymer MatrixComposite Materials and Their Laminates, is used to test fiber-metal laminates (FMLs),although its scope is limited to high-modulus fiber-reinforced composite materials. Thesetwo groups of materials have differences in their mechanical behavior, and it is possible thatthis standard cannot be employed in FMLs in its current status. To verify this, short-beam shear(SBS) tests were performed in aramid aluminum laminate (ARALL) 3 4/3 specimens employingtwo sets of rollers diameters. One set was in accordance with ASTM D2344/D2344M-16,whereas the other made use of smaller diameters. The options to stop the tests presentedin the standard were not adequate for the ARALL specimens using the normalized rollers diameters.Modifications to the standard in order to include FML specimens are suggested as follows:to include a test rig with reduced roller diameters, to observe of delamination at one sideof a specimen as a new option to stop the test, and to define the short-beam strengths (F~(sbs)) asthat corresponding to the maximum load value observed previous to a total load drop-off of30 %. The difference between the means of F~(sbs) obtained with both set of rollers was notsignificant when using these modifications.