#$%^&*AU2020101295A420200813.pdf#####ABSTRACT The invention proposes a gradient pressure-keeping sealed device and method for Split-Hopkinson pressure bar (SHPB) experiment of coal containing gas under confining pressure, and is suitable for the technical field of gas adsorption and desorption experiments and impact loading experiments of material dynamic mechanical properties. The proposed device is composed of a middle cavity, pressure-keeping cavities, a linear guide rail, a clamp, air inflation ports, an exhaust port and sealing elements, wherein the middle cavity and the pressure-keeping cavities form left and right cavities which are fixed to the linear guide rail. The sealing elements are respectively mounted in grooves of round holes in contact with bars and grooves of contact sides of the combined left and right two cavities. Two of the air inflation ports in side faces of the cavities are connected with pipe fittings of air bottles. The other air inflation port in the middle cavity is connected with a gas adsorption pipe fitting. The exhaust port is connected with a vacuum pump and an exhaust gas collection tank. The proposed device is connected to the Hopkinson bar. After the middle cavity is pumped to be a vacuum state, gas is respectively inflated into the middle cavity and the pressure-keeping cavities, wherein the pressure of each pressure-keeping cavity is equal to about a half of the pressure of the middle cavity. After a specimen completely adsorbs the gas, an impact experiment is started. The present invention solves the problem that the specimen is influenced by confining pressure and gas contained in coal. Additionally, gradient pressure keeping is utilized to ensure the airtightness of the device. The device has simple structure, reasonable design, operation convenience and strong practicability, and can improve the success ratio of the experiment.DRAWINGS 1/3 adscrberE 4. IL d LIIIIZ FIG.1I
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