Strength testing fixture using uniaxial testing machine for variable-proportion biaxial loading

Abstract

The invention provides a biaxial tensile strength testing fixture. With the fixture, variable-proportion biaxial tensile strength testing of a cross sample can be carried out with a uniaxial testing machine. The fixture is characterized by comprising an upper chuck, a primary lever crossbeam, a primary connecting rod, a secondary lever crossbeam, a secondary connecting rod, a loosening and tightening nut, a wire rope connector, a wire rope, a grooved flywheel, a bearing pedestal, a bearing, cross guide rails, a clamp with a slide block, a test piece, a base and a lower chuck. With the fixture, biaxial tensile strength testing of various load proportions can be implemented with the uniaxial testing machine. The fixture distributes pulling force at four directions in virtue of the lever balance theory, and pulling force at two axial directions of the test piece can be solved through static equilibrium, so usage of force sensors is avoided; moreover, the uniaxial testing machine is made full use of, the problems of lack of special biaxial strength testing equipment and high testing cost are overcome, and technical support is provided for determination of material performance and structural strength.

Description

technical field [0001] The invention designs a biaxial tensile strength test jig, which realizes the biaxial tensile strength test of various loading ratios on a cross plate sample by using a uniaxial testing machine, and belongs to the technical field of test and test. Background technique [0002] In recent years, with the rapid development of material technology, because of its excellent performance (high specific strength, high specific stiffness, excellent fatigue performance and good designability, etc.), planar braided composite materials are more and more used in Replace traditional metal structures in engineering structures, especially in the field of aerospace, such as helicopter composite blades, aircraft skins, engine bearings, etc. However, unlike isotropic traditional metal materials, planar braided composite materials are generally anisotropic, and their strength and elastic properties cannot be determined by simple unidirectional tests like metal materials. S...

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Problems solved by technology

Considering that the uniaxial test of metal materials has been developed very maturely at present, and the use of uniaxial testing machines has become very common, for this reason, this paper has invented a strength test jig with variable ratio biaxial loading, which can be used in single The variable-ratio biaxial tensile strength test is carried out on the axial testing machine, which solves the problem of lack of special equipment for biaxial strength test and high test cost, and provides technical support for the determination of material properties and structural strength

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