Sample for testing high-temperature shearing intensity of composite material and method thereof

Abstract

The invention relates to a sample for testing high-temperature shearing intensity of a composite material and a method thereof, which belong to the field of high-temperature mechanical properties testing of the composite material. A first notch and a second notch are respectively and horizontally arranged on an in-plane shearing sample close to an upper end and a lower end, the first notch and thesecond notch pass through a thickness direction of the sample, lengths of the first notch and the second notch are greater than half width of the sample, roots of the first notch and the second notchare in a straight square shape, the first notch and the second notch are anti-symmetric by relating to the sample, a notch 1 and a notch 2 are respectively and horizontally arranged on an interlayershearing sample close to the upper end and the lower end, the notch 1 and the notch 2 pass through a width direction of the sample, the lengths of the notch 1 and the notch 2 are greater than half thickness of the sample, roots of the notch 1 and the notch 2 are in the straight square shape, and the notch 1 and the notch 2 are anti-symmetric by relating to the sample. the in-plane or interlayer shearing sample is loaded according to constant displacement until the sample is fractured, and the high-temperature shearing intensity of the in-plane or interlayer shearing sample composite material is calculated by using a shearing formula. The sample is used for testing the high-temperature shearing intensity of the composite material.

Description

technical field [0001] The invention belongs to the field of testing the high-temperature mechanical properties of composite materials, and in particular relates to a sample and a method for testing the shear strength of composite materials. Background technique [0002] Composite materials have been widely used in aerospace and other fields due to their high specific strength and specific stiffness, designability of microstructure and many other advantages. In aerospace, composite materials have been gradually applied to the design of aircraft thermal protection systems. Therefore, the basic mechanical properties of composite materials in high-temperature and even ultra-high-temperature environments are related to the safety and reliability of thermal protection systems. The high temperature shear strength of composite materials is one of the important mechanical properties. [0003] At present, there is no uniform standard for testing the shear strength of composite mater...

AI Technical Summary

Problems solved by technology

The authorized announcement number is CN104458574B, and the authorized announcement date is January 04, 2017. The invention patent "A device and method for testing shear strength under ultra-high temperature or large temperature difference environment" discloses a testing method, which is mainly used for dissimilar materials. For the test of connection shear strength, the temperature is raised by radiant heating, and the temperature of the sample is adjusted by passing cooling water. This method has a slow heating rate and is not sensitive enough for temperature control.

The authorized announcement number is CN205228933U, and the authorized announcement date is May 11, 2016. The utility model patent "split-type fixture for testing the high-temperature in-plane shear strength of ceramic matrix composite materials" discloses a fixture and a test method, but this fixture The design is too complex, requires a large experimental space and is not conducive to heating

He Xubin designed a C / C composite interlaminar high-temperature shear specimen "Mechanical Strength" in "2.5D-C / C Composite High-temperature Interlaminar Shear Strength", 2010, Gou Jianjie in "Integral Felt Carbon / A C / C composite in-plane shear specimen was designed in "Research on High Temperature Shear Properties of Carbon Composite Materials" "Materials Herald", 2013, but the horizontal distance between the bottom ends of the two cutouts of the two specimen forms is zero, due to the non-uniformity of the composite material, the experimental results are more discrete, and it is easy to be damaged in the non-gauge distance area

[0004] In the normal temperature environment, some methods for testing the shear strength of composite materials have been formed, but in the high temperature and ultra-high temperature environment (2600 ° C), due to the limitations of heating methods, high temperature clamping methods, high temperature environment and test space, etc., The design and test method of shear strength specimens under high temperature and ultra-high temperature environment of composite materials has always been a difficult point in mechanical testing

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