Clamp for high temperature tensile test of ceramic matrix composite material

Abstract

The invention relates to a clamp for a high temperature tensile test, in particular to a clamp for the high temperature tensile test of a ceramic matrix composite material. The clamp provided by the invention consists of a main clamping head and an auxiliary clamping head, wherein one end of the main clamping head is a cylindrical end, and a wedge surface is arranged at the other end of the main clamping head; the auxiliary clamping head is T-shaped and the section of the auxiliary clamping head is U-shaped; the auxiliary clamping head is used for clamping a test piece; a threaded hole is formed on the T-shaped surface of the auxiliary clamping head; the cylindrical end of the main clamping head is connected with a testing machine; and the wedge surface end of the main clamping head is connected with the auxiliary clamping head. When the test piece is tensioned, the two sides of the clamping end is tensioned by the main clamping head and the middle part of the clamping end is tensioned by the auxiliary clamping head, so that the test piece clamping end is relatively uniform in stress, the clamping end is prevented from being first damaged when the test piece is tensioned, and the success rate of the tensile test is greatly improved; the adopted test piece is a plate-shaped test piece with equal thickness, is convenient to machine and good in economy; the main clamping head and the auxiliary clamping head are made of high-strength high-temperature-resistant materials; and the clamp for the high temperature tensile test of the ceramic matrix composite material is also applicable to tensile tests of other high-temperature-resistant materials with relatively poor shearing strengths.

Description

technical field [0001] The invention relates to a high-temperature tensile test jig, in particular to a high-temperature tensile test jig for a ceramic matrix composite material. Background technique [0002] Ceramic matrix composites have the advantages of high specific strength, high specific stiffness, high temperature resistance and low density, and have certain toughness, so they are ideal high-temperature structural materials. It has broad application prospects in the fields of national defense, energy, equipment manufacturing and automobiles. Since ceramic matrix composites are mainly used in high-temperature environments and are subject to loads, the testing of their high-temperature mechanical properties is particularly important, and tensile testing is the most basic and important means to obtain the mechanical properties of materials. [0003] In the tensile test of ceramic matrix composites, the testing machine fixes the specimen and applies the load through the...

AI Technical Summary

Problems solved by technology

Its disadvantage is that there will be a stress concentration area at the clamping position at both ends of the test piece, and the shear stress in the stress concentration area is relatively large, which can easily cause damage to the test piece, and the test piece cannot be finally broken.

Therefore, the fixture is usually only applied to laminated or braided ceramic matrix composites with high shear resistance, but not to unidirectional fiber-reinforced ceramic matrix composites with poor shear strength.

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