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CN-117214006-B - Low-temperature test system applied to Hopkinson bar test and application method thereof

CN117214006BCN 117214006 BCN117214006 BCN 117214006BCN-117214006-B

Abstract

The low-temperature test system applied to the Hopkinson rod test and the application method thereof comprise a Hopkinson rod test device, an ice making device and a low-temperature test device, wherein the Hopkinson rod test device comprises an incidence rod and a transmission rod, the ice making device is used for preparing bubble-free cylindrical pure ice, the low-temperature test device is used for fixing the bubble-free cylindrical pure ice between the incidence rod and the transmission rod of the Hopkinson rod test device and providing a low-temperature environment lower than-15 ℃ for the bubble-free cylindrical pure ice, the incidence rod and the transmission rod, and the Hopkinson rod test data accuracy can be improved through the arrangement.

Inventors

  • NIU LEILEI
  • ZHU WANCHENG
  • LUO KE
  • ZHAO WEI
  • HOU CHEN

Assignees

  • 东北大学

Dates

Publication Date
20260512
Application Date
20230830

Claims (6)

  1. 1. The utility model provides a be applied to hopkinson's bar test's low temperature test system, includes hopkinson's bar test device, hopkinson's bar test device includes incident rod (301), transmission pole (302), its characterized in that still includes: An ice making device (1), wherein the ice making device (1) is used for preparing bubble-free cylindrical pure ice; the low-temperature test device (2) is used for fixing the bubble-free cylindrical pure ice between an incidence rod (301) and a transmission rod (302) of the Hopkinson rod test device, and providing a low-temperature environment of-25 ℃ to-15 ℃ for the bubble-free cylindrical pure ice, the incidence rod (301) and the transmission rod (302); The ice making device (1) comprises a silica gel container (101), a cylinder container (102), a top cover (103), a base (104), a heat preservation layer (105) and a heat preservation cover (106), wherein the silica gel container (101) is of a cylindrical container structure with an upper opening and is arranged on the base (104), the cylinder container (102) is of a circular tubular structure with an upper opening and a lower opening, the inner diameter of the cylinder container (102) is the same as the outer diameter of the silica gel container (101), the height of the cylinder container (102) is the same as the height of the silica gel container (101), the cylinder container (102) is sleeved on the periphery of the silica gel container (101), the heat preservation layer (105) is coated on the outer side wall of the cylinder container (102), The top cover (103) is arranged above the cylinder container (102), and a vertical pressure relief through hole (107) communicated with the inner cavity of the silica gel container (101) is arranged on the top cover (103), and the heat preservation cover (106) is arranged on the top cover (103); The ice making device (1) further comprises a bolt (108) and a nut (109), through holes are formed in the top cover (103) and the base (104) which are positioned on the outer side of the cylinder container (102), the bolt (108) penetrates through the through holes in the top cover (103) and the base (104) to be in threaded connection with the nut (109), the top cover (103) is connected with the base (104) through the nut (109) and the bolt (108), and the top cover (103) and the base (104) clamp the silica gel container (101) through the bolt (108); The low-temperature test device (2) comprises a Dewar bottle (201), a self-pressurizing liquid nitrogen pump (202), a liquid nitrogen pump valve (203), a pressure gauge (204), a low-temperature conduit (205) and a heat preservation cylinder (240), wherein the self-pressurizing liquid nitrogen pump (202) is connected with the Dewar bottle (201) through a pipeline, the liquid nitrogen pump valve (203) and the pressure gauge (204) are arranged on the pipeline connected with the Dewar bottle (201) through the self-pressurizing liquid nitrogen pump (202), the low-temperature conduit (205) is used for communicating the Dewar bottle (201) with a box body (206), an inlet of the low-temperature conduit (205) is connected with the self-pressurizing liquid nitrogen pump (202), an outlet of the low-temperature conduit (205) is positioned in the box body (206), The heat-insulating box is characterized in that rod holes (223) are formed in the left side wall and the right side wall of the box body (206), the heat-insulating cylinder (240) is of a round tubular structure, two groups of heat-insulating cylinders (240) are arranged on the left side wall and the right side wall of the box body (206) and are respectively arranged on the left side wall and the right side wall of the box body, the heat-insulating cylinders (240) are communicated with the rod holes (223), heat-insulating cotton is arranged on the inner periphery of the end part, far away from one side of the box body (206), of the heat-insulating cylinder (240), and the ends of the incident rod (301) and the transmission rod (302) sequentially penetrate through the heat-insulating cylinders (240) and the rod holes (223) to extend into the box body; The novel multifunctional sample supporting device is characterized in that a box lifting support (207) is arranged at the bottom of the box (206), the height of the box (206) can be adjusted by the box lifting support (207), a sample support (208) is arranged inside the box (206), the sample support (208) comprises a bottom supporting upright post (209), a sample supporting upright post (210) and a heightening knob (211), the bottom supporting adjusting tube is of a circular tubular structure, the lower part of the sample supporting upright post (210) is positioned in a tube cavity of the bottom supporting adjusting tube, a screw hole is formed in the side wall of the bottom supporting adjusting tube, the end part of the heightening knob (211) is screwed into the screw hole in the bottom supporting adjusting tube and is propped against the side wall of the sample supporting upright post (210), and a V-shaped support is arranged at the upper end of the sample supporting upright post (210) and used for placing samples.
  2. 2. The low-temperature test system applied to the hopkinson bar test according to claim 1, wherein the box body lifting bracket (207) comprises a fine tuning knob (234), a fixed support (225), a lifting support (226), a guide rail (227), a rotating shaft (228), a lifting rotating component (229) and a lifting support (230); The fixing support (225) comprises a bottom fixing plate (231), a fixing block (232) and a base (233), wherein the fixing block (232) and the base (233) are arranged on the bottom fixing plate (231), a threaded through hole for allowing a fine tuning knob (234) to pass through is formed in the fixing block (232), the fine tuning knob (234) is screwed into the threaded through hole of the fixing block (232), the end head of the fine tuning knob (234) passes through the threaded through hole in the fixing block (232) and is located at the rear side of the fixing block (232), and the extending length of the end head of the fine tuning knob (234) from the threaded through hole is adjusted by rotating the fine tuning knob (234); The lifting support (226) comprises a slide base top plate (238) and a slide base (239), the slide base top plate (238) is arranged at the upper end of the slide base (239) and fixedly connected with the box body, the slide base (239) is arranged on one side of the base (233) and the slide base (239) is attached to the base (233), and a guide rail (227) is arranged between the slide base (239) and the base (233); The lifting rotating component (229) comprises a first support arm (235), a second support arm (236) and an annular ring (237), the annular ring (237) is of an annular structure, one end of the first support arm (235) and one end of the second support arm (236) in the length direction are connected with the periphery of the annular ring (237), a rotating shaft (228) is arranged on a base (233) of the fixed support (225), the lifting rotating component (229) is sleeved on the rotating shaft (228) through the annular ring (237) and can rotate relative to the rotating shaft (228), the lifting rotating component (229) is positioned at the rear side of a fixed block (232) of the fixed support (225), the end of a fine tuning knob (234) is in contact with the first support arm (235) of the lifting rotating component (229), a lifting strut (230) is arranged on the lower end face of a sliding base top plate (238) of the lifting support (226), the lifting strut (230) is positioned above the second support arm (236) of the lifting rotating component (229), the first lifting rotating component (235) of the lifting rotating component (229) is pushed by the end of the fine tuning knob (234) to enable the lifting rotating component (236) to lift the sliding base (236) to rotate upwards, the lifting support (226) is driven to move upwards along the guide rail (227).
  3. 3. The low-temperature test system for Hopkinson bar test according to claim 1, wherein the box (206) is a box structure formed by surrounding an upper cover plate (212), a front cover plate (213), a rear cover plate (214), a left side plate (215), a right side plate (216) and a bottom plate (217), a top window (218) is arranged on the upper cover plate (212), a front window (219) is arranged on the front cover plate (213), the rear end of the upper cover plate (212) is connected with the upper end of the rear side plate (214) through a hinge, a handle is arranged on the upper end surface of the upper cover plate (212), sliding grooves are formed on the side surfaces, close to the inner side of the box (206), of the left side plate (215) and the right side plate (216), the front cover plate (213) is inserted between the left side plate (215) and the right side plate (216) through the sliding grooves on the left side plate (215), the left side edge of the front cover plate (213) is positioned in the sliding grooves on the left side, the right side edge of the front cover plate (213) is positioned in the upper side grooves, the right side edge of the front cover plate (213) is positioned in the right side edges of the right side plates (216), the upper end surface of the front cover plate (213) is positioned in the upper side grooves on the right side edges of the upper side plates (215), the upper end surfaces of the front cover plate (213) and the upper cover plate (213) are attached to the upper end surfaces of the upper cover plate (213) and the upper cover plate (213) The right side plate (216) is provided with heat preservation cotton towards the contact position, and the tightness between the upper ends of the front cover plate (213), the rear side plate (214), the left side plate (215) and the right side plate (216) and the upper cover plate (212) is improved.
  4. 4. The low-temperature test system applied to the hopkinson bar test according to claim 2, further comprising a temperature monitoring system, wherein the temperature monitoring system comprises a temperature sensor (220), a temperature display (221) and a temperature alarm (222), the temperature sensor (220) is arranged in the box body (206) and is used for detecting the temperature in the box body (206), the temperature display (221) is arranged outside the box body (206), the temperature sensor (220) is connected with the temperature display (221) and is used for transmitting a temperature signal to the temperature display (221), the temperature display (221) displays a temperature value, the temperature alarm (222) is connected with the temperature display (221), and when the temperature exceeds a set temperature, the temperature alarm (222) gives an alarm.
  5. 5. The method of using a low temperature test system for hopkinson bar test as set forth in claim 4, comprising the steps of: S1, preparing bubble-free cylindrical pure ice by using an ice making device (1); S2, performing low-temperature freezing pretreatment for 48 hours at-20 ℃ on an incident rod (301) and a transmission rod (302) of a Hopkinson rod test device, then assembling a box (206) of the low-temperature test device (2) with the Hopkinson rod test device, and adjusting a box lifting bracket (207) at the bottom of the box (206) to enable the axes of the incident rod (301), the transmission rod (302), a heat insulation cylinder (240) and a rod hole (223) of the box (206) of the Hopkinson rod test device to be positioned on the same straight line; S3, adjusting a height adjusting knob (211) on the sample support (208) to ensure that the axis of the sample is positioned on the same straight line with the axis of the incident rod (301) and the axis of the transmission rod (302) when the bubble-free cylindrical pure ice is placed on the sample support (208), and turning on the lamp belt (224); S4, closing a box door, setting a temperature threshold of a temperature alarm (222), opening a self-pressurization type liquid nitrogen pump (202), enabling liquid nitrogen in a dewar bottle (201) to continuously and slowly enter a pipeline and uniformly spray into the box through a spraying device, enabling the temperature in the box to be rapidly reduced, and closing the liquid nitrogen pump when the temperature in a box body (206) is stably lower than-40 ℃; S5, rapidly opening an upper cover plate (212) of the box body (206), placing bubble-free cylindrical pure ice on a sample support (208) in the box body (206), and then closing the upper cover plate (212); S6, when the temperature in the box body (206) reaches a temperature range of minus 25 ℃ to minus 15 ℃, starting an impact test by using a Hopkinson bar test device, and impacting the bubble-free cylindrical pure ice by an incident bar (301); And S7, opening the upper cover plate (212) after the test is finished, opening the front cover plate (213), and cleaning and collecting the bubble-free cylindrical pure ice fragments in the box body (206).
  6. 6. The method of using a low temperature test system for hopkinson bar test set forth in claim 5, wherein the step S1 includes: S1.1, the top cover (103) and the heat preservation cover (106) are detached from the ice making device (1), vaseline is smeared on the inner side wall of the silica gel container (101) of the ice making device (1), and the upper end surfaces of the silica gel container (101) and the cylinder container (102), S1.2, boiling purified water and cooling the purified water to room temperature, using a syringe to extract the purified water, abutting the front end of a needle of the syringe on the lower bottom wall of a silica gel mold, slowly injecting the purified water to prevent air from being mixed in the injection process to generate bubbles, after the liquid level of the purified water in the silica gel mold has a certain height, keeping the needle of the syringe below a horizontal plane in the water injection process of the syringe, stopping water injection when the liquid level of the purified water reaches 95% of the height of the silica gel mold, generating bubbles on the inner wall of the silica gel mold in the whole water injection process, and using the needle of the syringe to puncture the bubbles; S1.3, after water injection is completed, a top cover (103) is mounted at the upper end of a silica gel container (101) by using a bolt (108) and a nut (109), the lower end face of the top cover (103) is attached to the upper end faces of the silica gel container (101) and a cylinder container (102), and then a heat preservation cover (106) is placed on the top cover (103); s1.4, the whole ice making device (1) is placed at the bottom of a-15 ℃ refrigerator, and purified water is frozen into bubble-free cylindrical pure ice in a silica gel mold.

Description

Low-temperature test system applied to Hopkinson bar test and application method thereof Technical Field The invention belongs to the technical field of rock dynamics, and relates to a low-temperature test system applied to a Hopkinson bar test and a use method thereof. Background The distribution of the high and medium-sized surface mines in the high and cold regions in China is quite wide, the rock mass contains hundreds of natural cracks, the cracks of the rock near the earth surface are filled with water under the action of underground water and rainfall, the rock and the water in the rock continuously undergo the cycle process of freezing-thawing under the action of day-night temperature difference and seasonal temperature change, the stability of the slope formed by surface mining is influenced by the freezing-thawing environment, and meanwhile, the slope is influenced by mining disturbance such as blasting, so that the slope is caused to generate landslide risk. Therefore, in order to evaluate the stability of the slope and the slope landslide protection, the dynamic mechanism of the rock and the dynamic mechanism of the ice are required to be tested, a mechanical model of the ice-containing filling jointed rock is established, and further the dynamic mechanical characteristics of the ice-containing filling jointed rock are studied. The Split Hopkinson Pressure Bar (SHPB) is one of the main test devices for researching the dynamic mechanical properties of rock at present, and the device is generally composed of three parts, namely an impact system, a rod system and a data acquisition and recording system, and is provided with high-speed photography and other devices for observing crack growth in the rock impact process. The conventional SHPB test device uses a steel rod as an incident rod and a transmission rod, but because the wave impedance of ice is smaller, the transmission wave measured by the steel rod is too small to be beneficial to test and analysis, therefore, the same rock as the field is selected to manufacture a long rock rod to replace the steel rod as the incident rod and the transmission rod, and in order to reproduce the influence of disturbance of high-cold dew weather, the frozen rock rod is required to be used for carrying out SHPB test to test the dynamic mechanism of the ice. The conventional SHPB test device cannot perform dynamic test under a low-temperature environment, and although a learner adopts liquid nitrogen to soak, spray alcohol, an ice chest and the like to cool, the method for realizing the low-temperature environment only enables the sample to be in a certain low-temperature environment and cannot enable rod systems at two ends of the sample to be in a low-temperature environment as a whole. In addition, if the dynamic mechanism of the ice is to be tested, firstly, a pure ice sample with few bubbles and a flat surface is prepared and placed in an SHPB test device to carry out dynamic impact test, but bubbles easily exist in the ice sample prepared by the existing ice making device at present, and the surface flatness of the ice does not meet the requirements of the SHPB test. Disclosure of Invention In view of the above, the invention discloses a low-temperature test system applied to a Hopkinson bar test, which comprises the following specific schemes: The utility model provides a be applied to hopkinson's pole test's low temperature test system, includes hopkinson's pole test device, hopkinson's pole test device includes incident rod, transmission pole, its characterized in that still includes: the ice making device is used for preparing bubble-free cylindrical pure ice; The low-temperature test device is used for fixing the bubble-free cylindrical pure ice between an incident rod and a transmission rod of the Hopkinson rod test device and providing a low-temperature environment of-25 ℃ to-15 ℃ for the bubble-free cylindrical pure ice, the incident rod and the transmission rod; The ice making device comprises a silica gel container, a cylinder container, a top cover, a base, a heat insulation layer and a heat insulation cover, wherein the silica gel container is of a cylindrical container structure with an upper opening and is arranged on the base, the cylinder container is of a circular tubular structure with an upper opening and a lower opening, the inner diameter of the cylinder container is the same as the outer diameter of the silica gel container, the height of the cylinder container is the same as the height of the silica gel container, the cylinder container is sleeved on the periphery of the silica gel container, the heat insulation layer is coated on the outer side wall of the cylinder container, The top cover is arranged above the cylinder container, a vertical pressure relief through hole communicated with the inner cavity of the silica gel container is formed in the top cover, and the heat preservation cover is arranged on the top cover. In addition