NF EN ISO 14126, T57-103 (10/2023)

This document specifies methods for the determination of the compression characteristics, in directions parallel to the lamination plane, of fiber-reinforced plastic composites, based on thermosetting or thermoplastic matrices. Compression characteristics are of interest for establishing specifications and for quality control. The specimens are machined from a flat test plate or from suitable finished or semi-finished products. Two loading methods and two types of specimens are described. The loading methods are: — method 1, which provides a shear load of the specimen (unsupported reference length) — method 2, which provides a mixed load of the specimen (reference length unsupported) NOTE For specimens with heels loaded using Method 2, the load is transferred by a combination of an end load and a shear load through the heels. The specimen models are as follows: — type A specimen: specimen with heels, of fixed thickness and rectangular cross section, used mainly for aeronautical type prepregs (~ 0,125 mm ply thickness); — type B specimen: specimen with or without heels, with several possible thicknesses and with a rectangular cross section, available in two sizes (B1 and B2). The Type A specimen is used for unidirectionally or biaxially reinforced materials tested in the grain direction, in which the fibers are normally aligned continuously or discontinuously (>7.5 mm). Types B1 and B2 specimens are used for mats, fabrics and other multidirectionally aligned reinforced materials, in which the fiber structure is more complex and/or coarser. This document gives criteria to verify that the combination of test method and specimen design results in valid fractures. It should be noted that alternative test method/specimen combinations will not necessarily give the same result. The methods specify certain dimensions for the specimens. Tests carried out with specimens of other dimensions or with specimens prepared under different conditions may give results which are not comparable. Other factors, such as the test speed, the support assembly used and the packaging of the specimens, may have an impact on the results.
(Automatic translation from French)