Clamp for testing mode I interlaminar fracture toughness in double-cantilever beam stretching test

Abstract

The present invention discloses a clamp for testing the mode I interlaminar fracture toughness in a double-cantilever beam stretching test. The clamp includes an upper clamping mechanism and a lower clamping mechanism which are of the same structure and are in mirror-image distribution; the upper clamping mechanism comprises a clamped portion, a clamping portion and a pin; one end of the clamped portion is held on a test machine, and the other end of the clamped portion is symmetrically provided with two first lugs; a first through hole is formed in each first lug; one end of the clamping portion is provided with a second lug; a second through hole is formed in the second lug; the other end of the clamping portion is connected with the end portion of one side of a test piece through an adhesive; the pin penetrates the first through holes and the second through hole; the second through hole is located between the two first through holes; two ends of the pin are in threaded connection with nuts; and the nuts abut against two sides of the clamping portion. With the clamp of the present invention adopted, the clamping and use of the testing machine can be facilitated, and it can be ensured that load applied in a stretching process does not deviate and is uniformly distributed.

Description

technical field [0001] The invention relates to the technical field of fixtures, in particular to a fixture for testing mode I interlaminar fracture toughness in a double cantilever beam tensile test. Background technique [0002] At present, composite materials are widely used in aerospace, new energy vehicles and weapons and military fields. Adhesive bonding is a commonly used connection method for composite materials, which has the advantages of strong structure, fatigue resistance, and high connection efficiency. Therefore, the research on the strength of composite bonded structures has very important theoretical value and engineering significance. [0003] To study the mode I fracture toughness of composite bonded structures, it is necessary to use the double cantilever beam test for testing. The existing double cantilever beam load transfer components mostly use loading blocks or piano hinges, but these two test fixtures have the following disadvantages: Although the...

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Problems solved by technology

[0003] To study the mode I fracture toughness of composite bonded structures, it is necessary to use the double cantilever beam test for testing. The existing double cantilever beam load transfer components mostly use loading blocks or piano hinges, but these two test fixtures have the following disadvantages: Although the loading block has a simple structure, it is inconvenient to be clamped by the testing machine; and the piano hinge cannot truly transfer the tensile load to the test piece evenly in terms of load transmission.

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