Automatic centering type direct rock tensile test device

Abstract

The invention discloses an automatic centering type direct rock tensile test device. The device comprises sample sleeve caps, ball-head tension rods, roll balls and sleeves; the sample sleeve caps areconnected with connecting members; ends of the connecting members are hinged with flexible anti-tensile ropes; the ends of the flexible anti-tensile ropes are hinged to the ends of tension rods of the ball-head tension rods; a plurality of the roll balls are disposed in embedding grooves along the end surfaces of the ball-head tension rods; and embedded groove covers are detachably disposed on the sleeves and located above the embedding grooves. According to the tensile test device, flexible anti-tensile ropes are adopted to connect ball-head turning members and the sample sleeve caps, and the roll balls and the sleeves as well as the roll balls and the ball-head turning members are in point contact, so that angles of the test device can be adjusted in all directions with flexible rotation and automatic deviation adjustment; after a rock sample is stressed, the tensile stress of the rock sample is always ensured along the axis, so that the problem of eccentric tensile stress is avoided; and the device is simple in structure, easy to operate, and easy to load and unload, and can accurately test the anti-tensile strength of the rock sample.

Description

Technical field [0001] The invention relates to a rock direct tensile test device, in particular to an automatic Chinese type rock direct tensile test device. Background technique [0002] Rock and concrete are common materials in infrastructure construction. Both types of materials have good compressive properties, but they are brittle and have low tensile strength. Therefore, accurate determination of the tensile strength of these materials is extremely important for rationally determining design parameters and avoiding brittle catastrophic damage to engineering structures. Important role. At present, there are two main types of test methods for determining the tensile strength of rocks: indirect method and direct method. The indirect method is to indirectly obtain the tensile strength of the tested material through the analysis of the internal force of the specimen under certain simplified assumptions, using specimens of different shapes, such as the Brazilian disc split met...

AI Technical Summary

Problems solved by technology

The upper and lower platens of this test device do not need to be strictly centered. Therefore, a rock tension device that uses spherical rollers to transmit loads can achieve non-eccentric tension to a certain extent, but there are still the following problems: spherical rollers Placed in the spherical groove of the lower platen, the surface contact is used to transfer the load, resulting in inflexible rotation between the ball head swivel and the spherical roller; in addition, the tie rod is rigid and can only be stretched in the axial direction. It cannot be guaranteed that the tensile stress of the rock sample is always along its axial direction after being stressed, and thus the problem of eccentric tensile stress cannot be avoided, resulting in inaccurate test results

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