A rolling friction reducer suitable for large-scale three-dimensional physical model tests

Abstract

A rolling friction friction reducer suitable for large-scale three-dimensional physical model tests, including a pressure head adapter plate, a fretting core, a core casing, a model sample pressure plate, and friction-reducing balls; the fretting core is located in the core casing One end of the fretting core extends to the outer side of the core body, the outer end of the fretting core is fixedly connected with the indenter adapter plate, the anti-friction ball is installed on the other end of the fretting core and can rotate freely, and the pressure plate of the model sample is fixed Installed on the core body jacket, the anti-friction ball is located between the fretting core body and the pressure plate of the model sample; there is a return spring on the side of the anti-friction ball, the return spring is located in the spring installation groove of the fretting core body, and the return spring is outside The end is connected with a support rod, and the outer end of the support rod is provided with a follower ball that can rotate freely, and the follower ball is in contact with the pressure plate of the model sample under the spring force of the return spring. The invention can establish a rolling friction friction reducing layer between the model sample and the actuator pressure head, effectively ensuring the friction reduction effect between the model sample and the actuator pressure head.

Description

technical field [0001] The invention belongs to the technical field of large-scale three-dimensional physical model tests, in particular to a rolling friction reducer suitable for large-scale three-dimensional physical model tests. Background technique [0002] At present, the scale of engineering rock mass involved in the mining of deep ore bodies is "kilometer" level, and the local failure scale of engineering rock mass has also reached "meter" level, but the rock mass test used in the traditional indoor rock mass mechanics test The samples are all at the "centimeter" level, and the damage scale of rock samples is only at the "millimeter" level. Therefore, it is difficult for traditional indoor rock mass mechanics tests to truly reveal the in-situ engineering geological failure phenomenon, and it is also difficult to accurately predict the construction process. potential engineering disasters. In order to overcome the shortcomings of traditional indoor rock mechanics test...

AI Technical Summary

Problems solved by technology

[0003] When the large-scale three-dimensional physical model test system is used to load the model sample, the model sample will inevitably be deformed. During the deformation process of the model sample, friction resistance will be generated on the contact surface between the model sample and the actuator pressure head. This frictional resistance will constrain the deformation of the model sample, which will lead to the inhomogeneity of the internal force of the model sample, thereby reducing the reliability of the test results.

[0004] For this reason, anti-friction treatment must be carried out between the model sample and the actuator pressure head. The friction reduction method adopted at this stage is realized by adding a polytetrafluoroethylene film between the model sample and the actuator pressure head. However, the anti-friction effect of polytetrafluoroethylene film in the traditional indoor rock mechanics test is acceptable, but in the large-scale three-dimensional physical model test, the anti-friction effect of polytetrafluoroethylene film is seriously reduced. The main reason is that the model The size of the sample has reached the "meter" level, resulting in the contact area between the model sample and the actuator indenter also increased from the traditional "centimeter" level to the "meter" level, while at the "meter" level The anti-friction effect of the PTFE film becomes worse and worse

[0005] Due to the deterioration of the friction reduction effect, the reliability of the test results obtained through the large-scale three-dimensional physical model test is also reduced. Therefore, in order to ensure the reliability of the large-scale three-dimensional physical model test results, it is urgent to find a new means of friction reduction

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