Tensile test loading device and test method for unidirectional fiber reinforced composite materials perpendicular to the fiber direction

Abstract

The invention discloses a loading device and method for testing the tension strength of a unidirectional fiber reinforced composite perpendicular to the fiber direction. The loading device comprises an upper clamping rod, a loading frame, a force transferring piece, a threaded connecting rod, a gap eliminating nut and a lower clamping rod. The force transferring piece comprises upper force transferring piece bodies and lower force transferring piece bodies, the upper force transferring piece bodies are pasted on the upper end of a unidirectional fiber reinforced composite test specimen, the lower force transferring piece bodies are pasted to the lower end of the unidirectional fiber reinforced composite test specimen, and fibers in the unidirectional fiber reinforced composite test specimen are perpendicular to the tension strength testing direction. The loading frame comprises an upper loading frame body and a lower loading frame body, the upper force transferring piece bodies are fixedly installed in the upper loading frame body, and the lower force transferring piece bodies are fixedly installed in the lower loading frame body. The upper clamping rod is fixedly connected with the upper loading frame body. The lower clamping rod is fixed to the lower loading frame body in a matched mode through the threaded connecting rod and the gap eliminating nut. The loading device has the advantages that damage, caused by clamping force of a tester, on the test specimen can be avoided, connecting gaps between clamp components can be eliminated, testing precision can be improved, and accurate alignment of the test specimen can be achieved.

Description

technical field [0001] The invention relates to the field of mechanical testing of composite materials, in particular to a tensile test loading device and a testing method for unidirectional fiber-reinforced composite materials perpendicular to the fiber direction. Background technique [0002] Fiber-reinforced composites have the advantages of high specific strength, high specific modulus, and good chemical stability, and are widely used in energy, military, and transportation fields. With the extensive application of fiber-reinforced composites, the testing methods of their mechanical properties have also received extensive attention. The mechanical performance parameters such as tensile strength, elastic modulus and Poisson's ratio of the material can be obtained through the tensile test of the fiber reinforced composite material, which has important guiding significance for the safe and reliable application of the composite material. [0003] Most of the tensile test me...

AI Technical Summary

Problems solved by technology

[0004] The tensile fixture disclosed in Chinese patent CN103018101A "A Fixture for High Temperature Tensile Testing of Ceramic Matrix Composite Materials" can be used for most structures of composite materials, but it is used for tensile strength of unidirectional fiber-reinforced composite materials perpendicular to the fiber direction. The specimen will fail at the contact surface of the grip during the tensile test

The fixture adopts bolt connection to clamp the sample, so the uneven force on the clamping section is prone to slipping

In addition, none of the technical solutions disclosed in the prior art involves the solution to the problem of eliminating the fit gap between the components of the combined fixture

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