A modified V-notched beam test method for interlaminar shear behavior of 3D woven composites

The V-notched beam test (VNB) is recognized as a standard test method to determine the shear properties of composite materials. But it is not easy to make sure that the specimen placed in a predetermined position; the force conditions of the specimen become very complex when the large deformation of the specimen is generated, the friction between the internal components of fixture cannot be ignored when bending moment is generated as well when using traditional V-notched beam test fixtures. A modified V-notched beam test fixture has been proposed and designed based on standardized apparatus. After improvement, specimen with different thicknesses can be positioned easily. Meanwhile, effects of friction and bending moment are greatly reduced, and it has been validated by finite element simulation. Furthermore, some typical of experiments have been carried out by using the proposed fixture to determine the interlaminar shear modulus and shear strength of a type of 3D woven composites. Some new experimental data are presented in this paper, which can provide guidance and help for future study and industrial design of the 3D woven composites.