Tensile and fracture-resistant dual-purpose test fixture for laboratory

Abstract

The invention relates to a tensile and fracture-resistant dual-purpose test fixture for a laboratory. The test fixture comprises a base, a telescopic rod, an upper pressing plate, a spring, buffer rubber gaskets, two side baffles, a fracture-resistant cushion block and a stable spring telescopic rod, the base is a cuboid plate, and grooves used for installing the baffles on the two sides and reserved holes used for installing the fracture-resistant cushion blocks are formed in the base. The telescopic rod is divided into three sections, the base is connected with the lowermost section of the telescopic rod, the upper pressing plate is connected with the uppermost layer of the telescopic rod, the working principle of the whole telescopic rod is similar to that of an umbrella main rod, the buffer rubber gaskets are installed at the buckle positions of the sections, and lubricating treatment is conducted on the inner wall of each telescopic rod to reduce the influence of friction force of each section of the telescopic rod on a test in the test process. The device disclosed by the invention can be used for completing tensile and bending tests, is easy to operate and low in cost, and can be used for effectively improving the accuracy of test data.

Description

technical field [0001] The invention relates to the field of mechanical tests of rock and concrete specimens, in particular to a dual-purpose test fixture for tensile and bending resistance in a laboratory. Background technique [0002] As we all know, large-scale projects such as coal mine roadways and tunnels need to conduct sufficient mechanical properties research on the rock mass in the project; similarly, concrete in large-scale civil engineering also needs to be tested for various mechanical properties. Because the tensile strength of rock and concrete is much smaller than its compressive strength, the geotechnical engineering accidents and civil engineering building failures that occurred on the project are basically caused by tensile failure. Therefore, the tensile strength of rock and concrete is an important parameter in the study of mechanical properties of materials. For the tensile test of rock and concrete, the laboratory usually uses the Brazilian split test...

AI Technical Summary

Problems solved by technology

[0004] The Brazilian splitting test usually has the following methods in laboratory experiments: (1) Place the specimen directly on the upper and lower loading plates of the press and then apply a vertical load, but when this method is loaded, the specimen may be subjected to Move when pressed, causing certain uncertainties to the experiment

(2) Cuboid pads are used up and down the cylindrical specimen, and then a vertical load is applied to the pads, but this method is easier to slip than the previous test

(3) Place pads with a diameter of 2 mm on the upper and lower sides of the specimen, and then apply vertical pressure through the upper and lower loading plates. Although this method has good test results, the existence of the pads may cause tension between the tensile load axis and the test specimen. The sample axes cannot be accurately coincided, which makes the test results deviate and cannot meet the requirements of the Brazilian split theory

In addition, the use of pads can easily cause the specimen to roll during the pressurization process, causing inconvenience in the test

[0005] Although the conventional tensile test fixtures are obtained in a simple way, the traditional tensile test fixtures are very easy to bring certain disturbances to the experiment during the test process.

During the loading process of the test piece, it is very easy to cause the test piece to shift due to the sliding of the test piece, which will affect the accuracy of the test results, especially when the method of pad loading is used.

In addition, it is difficult to ensure that the position of the pad is accurately located in the middle of the semicircle arc of the specimen during the tensile test when the pad is placed, so the data error is relatively large when the tensile test is destroyed

[0006] When collecting test mold information, it is found that most of the test piece fixtures have single functions. For example, some fixtures on the market can only do a single test. When doing different types of tests, the fixtures need to be replaced, which makes the test inconvenient.

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