Uniaxial tension compression system

Abstract

The invention discloses a uniaxial tension compression system. A hydraulic cylinder (7) is arranged just above a lower pressure head 6; a loading head (8) is arranged at the lower end of a piston of the hydraulic cylinder (7); a probe of a linear variable differential transformer (9) is downwards vertical and is contacted with the upper end of the piston of the hydraulic cylinder (7); the oil inlet of a servo valve (11) is connected with the oil outlet of a variable plunger type hydraulic pump (18); the oil return outlet of the servo valve (11) is connected with the oil return port of the variable plunger type hydraulic pump (18); a branch pipe (26) is connected to a second oil pipe (17'); the branch pipe (26) is connected with an oil nozzle (24) at the bottom of an energy accumulator shell (20); a capsule bag (22) is arranged in the energy accumulator shell (20); and the exterior of the capsule bag (22) is filled with hydraulic oil (25). According to the system disclosed by the invention, a fixture stress concentration effect is avoided, a test piece is completely in a stretched state in the test process, which is consistent with the experimental purpose, and the acquired test data is very intuitive, real and reliable.

Description

technical field [0001] The invention relates to a uniaxial tension and compression test system, which is used for the tensile strength test of rocks. Background technique [0002] Tensile strength is one of the important mechanical properties of rock, and it is also a controlling parameter for safety and stability analysis in rock structure design. The tensile strength of the rock refers to the ability of the rock specimen to resist tensile stress under the action of external load, which is the ratio of the ultimate load of the rock specimen to the tensile cross-sectional area when it is damaged by tension. Since the reform and opening up, with the rapid development of China's economic construction, many large bridges, tunnels, dams and high-rise buildings have been built. Rock materials are often encountered in engineering construction, and its mechanical performance index of tensile strength is an important basis for design, inspection, control and quality evaluation. Th...

AI Technical Summary

Problems solved by technology

The number and scale are large, the structure and environment are complex, and there are more and more problems related to the expansion of cracks in rocks and their deformation and failure under the action of tensile stress. It is no longer possible to continue to use rock mechanics models and failure criteria that mainly consider the state of compressive stress. Meet actual engineering needs

The rock mechanics model and failure criteria of the deformation and failure laws under the action of tensile stress are extremely imperfect, and the experimental data on rock tension is very limited, so it is urgent to study the deformation and failure characteristics of the rock under the action of tensile stress.

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