Solid propellant and coating tensile bond strength test fixture

Abstract

The invention discloses a fixture for tensile bonding strength test of solid propellant and coating, belonging to the field of test of explosive performance. The fixture comprises two sets of fixtures which are used symmetrically and have the same structure. Before test, the two ends of a propellant test sample are bonded on the small-diameter end faces of two coating test sample joints through a test adhesive respectively; two connecting rods are correspondingly and fixedly connected to pull rods on both sides of a tensile testing machine; two fixing seats are in threaded connection with the connecting rods; and the large-diameter ends of the two test sample joints and a limiting groove are fixed in corresponding fixing seats through two compression nuts in cooperation with two pairs of semicircular wristlets. According to the fixture, the problems of easy damage to the surface of the test sample and easy slippage and looseness of the test sample during low-temperature test, existing in the conventional tensile test fixture, are solved. Meanwhile, the test fixture has the advantages of simple structure, light weight, small size, convenience for clamping, high centering accuracy and the like.

Description

technical field [0001] The invention belongs to the field of propellant performance testing, and mainly relates to a fixture for testing the bonding strength of a solid propellant and a cladding layer, in particular to a fixture suitable for testing the tensile bond strength of a solid propellant and a cladding layer. Background technique [0002] The cladding layer plays a vital role in the orderly and controlled combustion of solid propellants. The quality of the bonding performance between the cladding layer and the surface of the solid propellant grain will directly affect the launch safety of the rocket motor. Bonding strength is an important index to evaluate the bonding performance of solid propellant and cladding layer. At present, the methods for measuring the bonding strength of solid propellant and cladding layer include wheel peeling method and tensile method. In the current tensile test, flat plate or V-groove clamps with anti-slip teeth are generally used in Ch...

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Problems solved by technology

The above-mentioned test fixture and test method have the following disadvantages: (1) the fixture structure is complicated, the volume is large, and the quality is large, and it is difficult to replace and maintain the fixture, especially the large-volume fixture is not conducive to operation in the high and low temperature test chamber; (2) When carrying out the tensile test, it is easy to pinch and damage the surface of the sample when the spring automatically locks the non-slip toothed flat plate or V-shaped groove fixture automatically, thus causing the sample to break from the limit position, resulting in test failure; (3) ) For a columnar propellant sample with high strength, it is easy for the sample to “pull off” from the fixture. At the same time, due to the small degree of freedom of the fixture, it is not easy to be centered on the same axis, and it is easy to force it when clamping the columnar sample. Damaged, resulting in large errors in measurement results

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