Split Hopkinson pressure bar provided with energy absorbing device and capable of simulating in-situ stress environment

Abstract

The invention relates to a split Hopkinson pressure bar provided with an energy absorbing device and capable of simulating an in-situ stress environment. A horizontal experimental platform is sequentially provided with a gas tank, an emitting cylinder, an impact bar, an incident end baffle, an incident bar, a confining pressure loading system, a transmission bar, a front-end energy absorbing bar,the shaft pressure loading and front-end energy absorbing device, a transmission end baffle, a connection bar, a rear-end energy absorbing bar, a cushioning pad layer and an energy absorbing baffle; the incident bar, the transmission bar and the rear-end energy absorbing bar are supported by a support, and the support and the horizontal experimental platform are fixed through bolts; the gas tank is mounted on the horizontal experimental platform through the bolts and connected with the emitting cylinder; and the incident end baffle, the confining pressure loading system, the transmission end baffle and the energy absorbing baffle are directly fixed to the horizontal experimental platform through bolts. According to the split Hopkinson pressure bar, the force bearing state of deep high-stress rock can be reflected more realistically, and meanwhile, through the design of an energy absorbing system, the stability of a dynamic testing system under the high stress and the high loading rateis ensured.

Description

technical field [0001] The invention relates to the field of testing devices for dynamic mechanical properties of materials, in particular to a separate Hopkinson compression bar with an energy absorbing device capable of simulating an in-situ stress environment. Background technique [0002] Compared with shallow rock engineering, the most obvious difference of deep rock lies in its special environment, among which high stress is one of the most important problems faced by the field of deep rock engineering. Water conservancy, transportation, energy and other engineering fields all involve the dynamic mechanical properties of deep rock materials. In order to ensure the safety of engineering structures and evaluate the stability of deep surrounding rocks, it is necessary to obtain accurate dynamic mechanical parameters of rocks under in-situ stress conditions. [0003] Due to the complexity of material dynamic response, laboratory quantitative research is the main research ...

AI Technical Summary

Problems solved by technology

Patent No. CN105758704 "A Hopkinson Compression Rod Confining Pressure Test Device" proposes a Hopkinson compression rod confining pressure device, which is to set an anti-recession groove on the incident rod and the transmission rod to solve the problem of the lower incidence rod and the transmission rod. In the problem of being away from the sample due to the confining pressure, but the existence of the anti-recession groove changes the size of the test rod, which has a non-negligible impact on the propagation of the stress wave. At the same time, the existence of the metal sleeve and the rubber sleeve increases the incidence The friction force of the rod under high confining pressure also causes a non-negligible error to the propagation of the stress wave

Patent No. CN104677725 "A New Confining Pressure Cylinder Device for Active Confining Pressure Experiment of Hopkinson Compression Rod" connects the metal sleeve, rubber sleeve and compression block as a whole, which solves the problem that the test rod cannot press the test piece tightly under high pressure. However, due to the existence of the metal sleeve, there are uncontrollable factors in the determination of the confining pressure value imposed by the oil cylinder on the specimen, which affects the experiment

To sum up, the existing improved Hopkinson compression bars cannot realize multiple in-situ stresses and high loading rate loading conditions at the same time, and there is less discussion on the elimination of high confining pressure and impact residual energy. The test has strong kinetic energy. If it is directly absorbed by the test rod system, it will affect the stability of the entire experimental system.

[0004] In the existing Hopkinson pressure rod with confining pressure, the samples are all sealed in the sealed oil cylinder, and the deformation characteristics of the rock during the loading process cannot be visually inspected

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