Reinforced hollow structure test piece sample preparation device and sample preparation method

Abstract

The invention relates to the technical field of test piece preparation, and particularly discloses a reinforced hollow structure test piece sample preparation device and a sample preparation method. The reinforced hollow structure test piece sample preparation device comprises a base, a sample mold part and a positioning part, the sample mold part comprises an inner core mold, a first outer mold and a second outer mold, the inner core mold is arranged on the base, at least one of the first outer mold and the second outer mold is rotationally connected to the base, and the first outer mold rotationally covers the second outer mold. The positioning component comprises a supporting piece, a plurality of adjusting pieces and a plurality of positioning pieces, the supporting piece is connected to the top plate of the first outer mold and the top plate of the second outer mold, a positioning ring is formed on the supporting piece and arranged on the outer wall face of the inner core mold in a sleeving mode, the adjusting pieces are arranged on the positioning ring in a surrounding mode, and each adjusting piece is connected with one positioning piece. With the adoption of the device, the positioning ring, the adjusting piece and the positioning piece are matched, so that the uniformity of the thickness of a test piece protection layer after concrete pouring can be effectively ensured, and the forming quality of the hollow structure test piece is effectively ensured.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of test piece preparation, in particular to a reinforced hollow structure test piece sampling device and method. BACKGROUND

[0002] The combined structure formed by the combination of materials such as concrete, steel and FRP can be widely applied to engineering projects such as bridge piers, arch ribs, industrial pipelines and wind power towers, and the stress performance of the combined structure can be studied by forming small structure test pieces. Common small structure test pieces include circular or square steel-concrete combined structure test pieces. The small structure test pieces can be divided into solid structure test pieces with steel bars inside and hollow structure test pieces without steel bars inside according to the structure. For hollow structure test pieces, especially those with large hollow rates (thin-walled) or steel cages, the forming efficiency and quality are difficult to guarantee.

[0003] Unlike the process of forming hollow thin-walled test pieces by centrifugal method in engineering, it is difficult to provide mature small centrifugal equipment and corresponding operating conditions in the laboratory. Although PVC pipes and foam cores can be used as inner molds for forming, the outer mold and inner mold cannot be accurately positioned, which easily leads to low positioning accuracy of the steel cage in the interlayer and uneven thickness of the protective layer, resulting in low forming quality of the reinforced hollow combined structure test piece and affecting the accuracy of the stress performance research results of the hollow structure test piece in subsequent experiments. SUMMARY

[0004] In order to solve the defects of the prior art, the present application provides a reinforced hollow structure test piece sampling device and method, which can effectively guarantee the uniformity of the protective layer thickness of the test piece after pouring concrete and effectively guarantee the forming quality of the hollow structure test piece.

[0005] In order to solve the above technical problems, the present application provides a reinforced hollow structure test piece sampling device, which comprises a base, a sample mold part and a positioning part. The sample mold part comprises an inner core mold, a first outer mold and a second outer mold. The inner core mold is arranged on the base. At least one of the first outer mold and the second outer mold is rotatably connected to the base. The first outer mold is rotatably closed on the second outer mold, and the inner core mold, the first outer mold and the second outer mold form a sampling area.

[0006] The positioning part comprises a support, a plurality of adjusting parts and a plurality of positioning parts. The support is connected to the top plate of the first outer mold and the second outer mold. The support forms a positioning ring, which is sleeved on the outer wall surface of the inner core mold. A plurality of adjusting parts are arranged around the positioning ring, and each adjusting part is connected to one positioning part. The adjusting part is used to adjust the relative distance between the positioning part and the test piece reinforcement, and connect the positioning part and the test piece reinforcement.

[0007] As an improvement of the above-mentioned scheme, a positioning groove is formed on the bottom surface of the reinforcement of the test piece, and a magnetic attraction member is arranged on the inner wall surface of the positioning groove; the base is provided with an electric magnetic attraction device, and the magnetic attraction member is electrically connected with the electric magnetic attraction device.

[0008] As an improvement of the above-mentioned scheme, the base is formed with a vertical rod, and the first outer mold and the second outer mold are both rotationally connected with the vertical rod; the positioning ring is formed with a first connecting rod, and one end of the first connecting rod is formed with a sleeve hole, and the first connecting rod is sleeved on the vertical rod through the sleeve hole.

[0009] The bottom of the sleeve hole is formed with a connecting groove, and the vertical rod is formed with a limiting block, and the connecting groove is embedded in the limiting block.

[0010] As an improvement of the above-mentioned scheme, the inner core mold is an inflatable inner core mold, the inner core mold is formed with a gas injection port and a gas exhaust port, and the base is provided with an inflation device, and the gas injection port and the gas exhaust port are both in communication with the inflation device.

[0011] The first outer mold and the second outer mold are both formed with a shell and a second connecting rod, the shell is rotationally connected with the vertical rod through the second connecting rod, the shell is formed with a closing surface, the closing surface of the first outer mold abuts against the closing surface of the second outer mold when the first outer mold is rotationally closed on the second outer mold, and the closing surface is provided with a sealing member.

[0012] As an improvement of the above-mentioned scheme, a strain gauge pasting component is further included, and the strain gauge pasting component includes a positioning disc, a pressing member, a transmission assembly and a positioning and pasting assembly.

[0013] The positioning disc is installed on the base, the pressing member is connected with the positioning disc, the extending end of the pressing member is connected with the transmission assembly, the transmission assembly is in transmission connection with the positioning and pasting assembly, and the pressing member is adapted to be switched between a pressing state and a lifting state, wherein in the pressing state, the pressing member moves downward to drive the positioning and pasting assembly to move transversely in a direction away from the transmission assembly, and in the lifting state, the pressing member moves upward to drive the positioning and pasting assembly to move transversely in a direction close to the transmission assembly.

[0014] As an improvement of the above-mentioned scheme, the positioning and pasting assembly includes a positioning plate for connecting a strain gauge and a transversely elongated rod, and the positioning plate is installed on one end of the transversely elongated rod away from the transmission assembly.

[0015] The transmission assembly comprises a vertical rack, a horizontal rack and a transmission gear set, wherein the vertical rack is connected to the protruding end of the pressing piece, the horizontal rack is connected to one end of the horizontal elongated rod towards the transmission assembly, and the vertical rack and the horizontal rack are in transmission connection with the transmission gear set.

[0016] As an improvement of the above scheme, the positioning plate is provided with a linkage rod, the middle part of the linkage rod is rotationally connected to the positioning plate, one end of the linkage rod is connected with a first movable block, the first movable block is formed with an embedding groove, the other end of the linkage rod is connected with a second movable block, the first movable block and the second movable block are both slidingly connected to the positioning plate, and the length of the first movable block is greater than the length of the second movable block, and the second movable block is located inside the embedding groove.

[0017] Correspondingly, the second aspect of the present application provides a method for preparing a reinforced hollow structure test piece, which is based on the reinforced hollow structure test piece preparation device of any one of the above aspects, and comprises the following steps:

[0018] Based on the size parameters of the test piece, the inner core mold is arranged on the base, the inner core mold is inflated, and a release layer is covered on the outer sidewall of the inner core mold;

[0019] The test piece reinforcement is sleeved on the side surface of the inner core mold, and the spatial position of the test piece reinforcement is determined by using the positioning component to complete the positioning and fixing of the test piece reinforcement;

[0020] The inner wall surface of the first outer mold and the inner wall surface of the second outer mold are covered with a release layer, the first outer mold and the second outer mold are wrapped around the test piece reinforcement, and the closed surface of the first outer mold and the second outer mold is sealed;

[0021] The inner core mold and the first outer mold and the second outer mold are poured with concrete to prepare the test piece;

[0022] When the test piece is preliminarily hardened, the positioning component is removed and lifted, and the test piece is supplemented with pouring to fill the hole above the test piece;

[0023] When the test piece reaches the preset strength, the first outer mold and the second outer mold are removed, and the internal gas of the inner core mold is released to complete the preparation of the test piece.

[0024] As an improvement of the above scheme, the step of determining the spatial position of the test piece reinforcement by using the positioning component to complete the positioning and fixing of the test piece reinforcement comprises:

[0025] The support is placed on the top of the first outer mold and the second outer mold by the sleeve hole of the first connecting rod, and the positioning ring is sleeved on the inner core mold;

[0026] The relative distance between the positioning member and the test specimen reinforcement is adjusted, and the positioning member is connected with the test specimen reinforcement;

[0027] The extension length of the adjusting member in the positioning ring is adjusted, the spatial position of the test specimen reinforcement in the sample preparation area is controlled, and it is ensured that the test specimen reinforcement is arranged vertically;

[0028] The magnetic attraction member in the positioning member is energized, and the test specimen reinforcement is fixed by the magnetism of the magnetic attraction member.

[0029] As an improvement of the above-mentioned scheme, after the step of releasing the first outer mold and the second outer mold, releasing the internal gas of the inner core mold, and completing the preparation of the test specimen, the method further comprises:

[0030] The strain gauge is attached to the inner hole wall surface of the test specimen by the strain gauge attaching component.

[0031] The implementation of the present application has the following beneficial effects:

[0032] In the present embodiment, when the hollow structure test specimen is prepared, the test specimen reinforcement is assembled on the outer surface of the inner core mold, then the positioning ring is sleeved on the outer wall surface of the inner core mold, and the positioning member is connected with the test specimen reinforcement by adjusting the position of the adjusting member. At this time, each adjusting member can be finely adjusted to adjust the relative distance between the positioning member and the test specimen reinforcement, so that the test specimen reinforcement remains vertical under the cooperation of the adjusting member and the positioning member, and the relative distance between the test specimen reinforcement and the outer surface of the inner core mold is constant, thereby completing the positioning of the test specimen reinforcement in the sample preparation area.

[0033] Then the first outer mold is rotated to cover the second outer mold, and the test specimen reinforcement and the inner core mold are surrounded by the first outer mold and the second outer mold, so that the sample preparation area between the inner core mold and the first outer mold and the second outer mold is poured with concrete, and the preparation of the hollow structure test specimen is completed.

[0034] Therefore, in the present embodiment, the positioning ring can use the outer surface of the inner core mold as a positioning reference, and the positioning of the test specimen reinforcement in the sample preparation area is completed by the cooperation of the adjusting member and the positioning member, which can ensure the spatial position accuracy between the test specimen reinforcement and the inner core mold, the first outer mold and the second outer mold, effectively ensure the uniformity of the test specimen protective layer thickness after pouring concrete, effectively ensure the forming quality of the hollow structure test specimen, and thereby improve the research accuracy of the stress performance research results of the hollow structure test specimen. BRIEF DESCRIPTION OF DRAWINGS

[0035] Figure 1 is a structural schematic diagram of a reinforcement hollow structure test specimen sample preparation device in the present application;

[0036] Figure 2 This is a schematic diagram of the base structure in this invention;

[0037] Figure 3 This is a schematic diagram of the structure of the first outer mold or the second outer mold in this invention;

[0038] Figure 4 This is a schematic diagram of the positioning component in this invention;

[0039] Figure 5 This is a cross-sectional view of the positioning component in this invention;

[0040] Figure 6 This is a schematic diagram showing the position of the strain gauge bonding component and the hollow structure specimen in this invention;

[0041] Figure 7 This is a cross-sectional view of the strain gauge bonding component in this invention;

[0042] Figure 8 This is a schematic diagram of the connection structure between the positioning and bonding component and the transmission component in this invention;

[0043] Figure 9 This is a cross-sectional view of the positioning and pasting component in this invention;

[0044] Figure 10 This is a schematic diagram of the transmission component in this invention;

[0045] Figure 11 This is a flowchart of the method for preparing reinforced hollow structure specimens in this invention. Detailed Implementation

[0046] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings. It is hereby declared that the directional terms such as up, down, left, right, front, back, inside, and outside used in this text are based solely on the accompanying drawings and are not intended to specifically limit the invention.

[0047] A first aspect of the present invention provides a sample preparation device for reinforced hollow structural specimens. For example... Figures 1 to 4 As shown, the sample preparation device for reinforced hollow structure specimens includes a base 1, a sample mold component 2, and a positioning component 3. The sample mold component 2 includes an inner core mold 21, a first outer mold 22, and a second outer mold 23. The inner core mold 21 is disposed on the base 1. At least one of the first outer mold 22 and the second outer mold 23 is rotatably connected to the base 1. The first outer mold 22 rotatably covers the second outer mold 23, and a sample preparation area is formed between the inner core mold 21, the first outer mold 22, and the second outer mold 23. The reinforcement 5 of the specimen is positioned and fixed in the sample preparation area by the positioning component 3.

[0048] The positioning component 3 includes a support 31, multiple adjusting components 32 and multiple positioning components 33. The support 31 is connected to the top plate of the first outer mold 22 and the second outer mold 23. The support 31 forms a positioning ring 34, which is sleeved on the outer wall of the inner core mold 21. Multiple adjusting components 32 are arranged around the positioning ring 34, and each adjusting component 32 is connected to a positioning component 33. The adjusting component 32 is used to adjust the relative distance between the positioning component 33 and the specimen reinforcement 5, and to connect the positioning component 33 and the specimen reinforcement 5.

[0049] In this embodiment, when preparing the hollow structure specimen, the specimen reinforcement 5 can be assembled onto the outer surface of the inner core mold 21. Then, the positioning ring 34 is fitted onto the outer wall of the inner core mold 21, and the positioning member 33 is connected to the specimen reinforcement 5 by adjusting the position of the adjusting member 32. At this time, each adjusting member 32 can be fine-tuned to adjust the relative distance between the positioning member 33 and the specimen reinforcement 5, so that the specimen reinforcement 5 remains vertical under the cooperation of the adjusting member 32 and the positioning member 33, while ensuring that the relative distance between the specimen reinforcement 5 and the outer surface of the inner core mold 21 remains constant, thereby completing the positioning of the specimen reinforcement 5 in the sample preparation area.

[0050] Then, the first outer mold 22 is rotated and covered by the second outer mold 23, and the first outer mold 22 and the second outer mold 23 are used to surround the specimen reinforcement 5 and the inner core mold 21, so that concrete can be poured into the sample preparation area between the inner core mold 21 and the first outer mold 22 and the second outer mold 23, and the hollow structure specimen is prepared accordingly.

[0051] Therefore, in this embodiment, the outer surface of the inner core mold 21 can be used as the positioning reference by the positioning ring 34, and the positioning action of the specimen reinforcement 5 in the sample preparation area can be completed by the cooperation of the adjusting member 32 and the positioning member 33. This can ensure the spatial position accuracy between the specimen reinforcement 5 and the inner core mold 21, the first outer mold 22, and the second outer mold 23, effectively ensure the uniformity of the specimen protective layer thickness after concrete pouring, effectively ensure the molding quality of the hollow structure specimen, and thus improve the accuracy of the research results on the stress performance of the hollow structure specimen.

[0052] It should be noted that the reinforcement 5 of the specimen is preferably a steel cage, which is fitted onto the outer surface of the inner core mold 21 and positioned and fixed by the positioning component 3, so that the steel cage and concrete are poured to form a hollow structural specimen with a steel cage. Of course, the reinforcement 5 of the specimen can also be a solid or hollow concrete specimen with its own composite pipe or steel pipe constraint, and the dimensions of the base 1, inner core mold 21, first outer mold 22 or second outer mold 23 can be changed according to the actual sample preparation structure.

[0053] Furthermore, after positioning the reinforcement 5 of the specimen in the sample preparation area, to ensure the stability of the reinforcement 5, such as... Figure 5As shown, the positioning member 33 is formed with a positioning groove 331 facing the bottom surface of the test specimen reinforcing bar 5, and the inner wall surface of the positioning groove 331 is provided with a magnetic member 332. The base 1 is provided with an electric magnetic equipment 12, and the magnetic member 332 is electrically connected with the electric magnetic equipment 12. When the test specimen reinforcing bar 5 needs to be fixed, the electric magnetic equipment 12 can be used to electrify the magnetic member 332, so that the magnetic member 332 generates a continuous and uniform magnetic attraction force to magnetically attract the test specimen reinforcing bar 5, complete the fixation of the test specimen reinforcing bar 5 in the sample preparation area, effectively resist the impact during the concrete pouring, and further ensure that the test specimen can form a uniform protective layer thickness after being formed.

[0054] Moreover, the top structure of the test specimen reinforcing bar 5 is adsorbed by the magnetic member 332, which facilitates the removal from the top of the test specimen after the test specimen preparation is completed, avoids the interference of the fixation structure of the test specimen reinforcing bar 5 on the molding of the test specimen, ensures that there is no mark or defect in the interior of the test specimen after being formed, and further ensures the molding quality of the test specimen.

[0055] Preferably, as shown in the drawings, Figure 5 The magnetic member 332 is a strong electromagnetic sheet. In order to facilitate the electrification of the strong electromagnetic sheet, a conductive structure 333 such as a conductive sheet is arranged on the side of the strong electromagnetic sheet away from the test specimen reinforcing bar 5, and the strong electromagnetic sheet is electrically connected with the electric magnetic equipment 12 through the conductive structure 333 to be electrified.

[0056] It should be noted that the side of the strong electromagnetic sheet facing the test specimen reinforcing bar 5 is provided with a buffer 334, which can be a thin layer of sponge to serve as a buffer when the strong electromagnetic sheet contacts the test specimen reinforcing bar 5, thereby reducing the impact force when the strong electromagnetic sheet contacts the test specimen reinforcing bar 5.

[0057] As an optional embodiment, as shown in the drawings, Figure 2 The base 1 is formed with a vertical rod 11, and the first outer mold 22 and the second outer mold 23 are both rotationally connected with the vertical rod 11. The positioning ring 34 is formed with a first connecting rod 35, one end of the first connecting rod 35 facing the vertical rod 11 is formed with a sleeve hole 351, and the first connecting rod 35 is sleeved on the vertical rod 11 through the sleeve hole 351. The bottom of the sleeve hole 351 is formed with a connecting groove 352, and the vertical rod 11 is formed with a limiting block 111, and the connecting groove 352 is embedded in the limiting block 111. When the positioning member 3 is assembled, the first connecting rod 35 can be sleeved on the vertical rod 11, and the connecting groove 352 of the sleeve hole 351 is embedded in the limiting block 111 to correspondingly determine the relative height of the positioning ring 34 relative to the inner core mold 21, thereby reducing the adjustment distance of the adjusting member 32 and the positioning member 33 relative to the test specimen reinforcing bar 5, achieving the reduction of the operation of the adjusting member 32, improving the sample preparation efficiency.

[0058] Preferably, the adjusting member 32 is an adjusting screw.

[0059] In order to improve the demolding convenience after the test specimen is formed, as shown in the drawings,Figure 1 As shown, the inner core mold 21 is an inflatable inner core mold, the inner core mold 21 is formed with a gas injection port and a gas exhaust port, and the base 1 is provided with an inflation device 18, and the gas injection port and the gas exhaust port are in communication with the inflation device 18. Before the preparation of the test piece, the inflation device 18 can be used to inflate the gas injection port, so as to use the inner core mold 21 to cooperate with the first outer mold 22 and the second outer mold 23 to prepare the test piece. After the preparation of the test piece is completed, the inflation device 18 can be controlled to release the gas of the inner core mold 21 from the gas exhaust port, so as to shrink the inner core mold 21, so that the outer surface of the inner core mold 21 is separated from the inner wall of the test piece, the test piece is realized without damage, the damage to the test piece during demolding is effectively avoided, and the inner core mold 21 can still be inflated and reused during subsequent test piece preparation, the operation steps of replacing the inner core mold 21 during test piece preparation are reduced, and the sample preparation efficiency of the hollow structure test piece is effectively ensured.

[0060] Further, in order to further reduce the damage to the test piece during demolding, the outer surface of the inner core mold 21, the inner wall surface of the first outer mold 22 and the inner wall surface of the second outer mold 23 are all arranged with a diaphragm layer, which is preferably a demolding agent, so as to provide surface protection for the test piece, the inner core mold 21, the first outer mold 22 and the second outer mold 23 by using the diaphragm layer, to avoid the inner core mold 21, the first outer mold 22 and the second outer mold 23 adhering to the inner and outer surfaces of the test piece, further ensuring the test piece to be demolded without damage, and further ensuring the forming quality of the test piece.

[0061] As shown in the figure, Figure 3 The first outer mold 22 and the second outer mold 23 are both formed with a shell 221 and a second connecting rod 222, the shell 221 is rotatably connected to the vertical rod 11 through the second connecting rod 222, the shell 221 is formed with a closing surface 223, and when the first outer mold 22 is rotatably closed on the second outer mold 23, the closing surface 223 of the first outer mold 22 abuts against the closing surface 223 of the second outer mold 23, and the closing surface 223 is provided with a sealing piece 224.

[0062] Further, after the test piece reinforcement 5 is positioned and fixed, the first outer mold 22 and the second outer mold 23 can be rotated towards the inner core mold 21, so that the closing surface 223 of the first outer mold 22 abuts against the closing surface 223 of the second outer mold 23, and the sealing piece 224 of the closing surface 223 is used to seal the first outer mold 22 and the second outer mold 23, so as to avoid leakage of concrete from the connecting gap between the closing surfaces 223 during subsequent pouring.

[0063] It should be further pointed out that the outside of the closing surface 223 is outwardly convex with a screw plate 225, and the screw plate 225 is arranged with a bolt connection hole, so as to use bolts or screws to close and connect the first outer mold 22 and the second outer mold 23, so as to ensure the overall stability of the outer mold during pouring of concrete.

[0064] It should be further noted that, in order to improve the first outer mold 22 and the second outer mold 23 to have sufficient compressive strength and stability, the outer side of the shell 221 is provided with a plurality of longitudinal ribs 226 and transverse ribs 227 to ensure that the first outer mold 22 and the second outer mold 23 can withstand the pressure exerted by the concrete during pouring, and to ensure the molding quality and efficiency of the test piece.

[0065] As an optional embodiment, in order to ensure the compactness of the test piece during molding, as shown in Figure 2 , the base 1 includes an upper base 13, a lower base 14, and a plurality of vibrating elements 15 which are spaced around the outer side of the upper base 13, so that when pouring concrete between the outer mold and the inflatable inner mold, the vibrating elements 15 around the upper base 13 vibrate the lower base 14, and the vibration is transmitted to the concrete through the lower base 14 and the outer mold, the bubbles generated during pouring are discharged, and the compactness of the concrete during molding of the test piece is improved, so as to obtain a hollow structural test piece with higher strength. The upper base 13 and the lower base 14 are connected by elastic support rods 16, so that when the vibrating elements 15 vibrate the lower base 14, the elastic support rods 16 absorb the vibration transmitted from the upper base 13 to the lower base 14, effectively preventing the vibration from affecting the surrounding test equipment.

[0066] Preferably, the vibrating elements 15 are high-frequency micro-vibrators, which utilize the characteristics of high frequency (usually operating at more than 100 Hz) and small amplitude to ensure the vibrating effect on the concrete. The high-frequency micro-vibrators can be fixed to the lower base 14 by matching bolts.

[0067] Further, as shown in Figure 2 , the top surface of the upper base 13 is provided with a horizontal indicating element 17, which is preferably a spirit level, so that after the outer mold surrounds the test reinforcement 5 and the inflatable inner mold, the horizontal indicating element 17 on the top surface of the upper base 13 can be used to check whether the upper base 13 is horizontal, to ensure that the test piece is not skewed after molding, and to further ensure the molding quality of the test piece.

[0068] In addition, it should be noted that after the test piece is molded, in order to facilitate subsequent experimental study on the internal mechanical behavior of the hollow structural test piece under complex load, strain gauges are usually attached to the inner wall surface of the hollow structural test piece. In the prior art, strain gauges are usually fixed by manual sticking, which is difficult when sticking to deep strain gauges, and can easily affect the sticking efficiency of the strain gauges.

[0069] As an optional embodiment, in order to improve the efficiency of sticking strain gauges to the inner wall surface of the hollow structural test piece, as shown in Figure 1 , Figure 6 and Figure 7As shown, the reinforced hollow structure specimen sampling device further comprises a strain gauge sticking component 4, which comprises a positioning disc 41, a pressing piece 42, a transmission assembly 43 and a positioning and sticking assembly 44, wherein the positioning and sticking assembly 44 is used for mounting the strain gauge.

[0070] The positioning disc 41 is mounted on the base 1, the pressing piece 42 is connected to the positioning disc 41, the extending end of the pressing piece 42 is connected to the transmission assembly 43, the transmission assembly 43 is in transmission connection with the positioning and sticking assembly 44, and the pressing piece 42 is adapted to switch between a pressing state and a lifting state, wherein in the pressing state, the pressing piece 42 moves downward to drive the positioning and sticking assembly 44 to move laterally away from the transmission assembly 43, and in the lifting state, the pressing piece 42 moves upward to drive the positioning and sticking assembly 44 to move laterally close to the transmission assembly 43.

[0071] It can be understood that when sticking the strain gauge, the positioning disc 41 can be arranged on the top surface of the hollow structure specimen, and the pressing piece 42, the transmission assembly 43 and the positioning and sticking assembly 44 can be extended into the internal hollow cavity of the hollow structure specimen. At this time, the distance between the transmission assembly 43 and the positioning disc 41 can be adjusted to move the positioning and sticking assembly 44 mounted with the strain gauge to a preset depth, wherein the preset depth is the depth of the hollow structure specimen where the strain gauge needs to be mounted. Then the positioning and sticking assembly 44 can be moved laterally to the inner wall surface of the hollow structure specimen by the pressing piece 42 through the transmission of the transmission assembly 43, so as to move and stick the strain gauge to the inner wall surface of the hollow structure specimen, and complete the sticking action of the strain gauge at the preset depth.

[0072] Therefore, during the whole process of sticking the strain gauge, the operator only needs to complete the depth adjustment action of the transmission assembly 43 and the pressing action of the pressing piece 42 outside the hollow structure specimen, effectively solving the problem of difficulty in manually sticking the strain gauge on the inner wall of the hollow structure specimen, thereby ensuring the sticking efficiency of the strain gauge.

[0073] It should be noted that the pressing piece 42 can comprise a sleeve and a pressing rod, the sleeve is connected to the top surface of the positioning disc 41, the pressing rod passes through the sleeve and is connected to the transmission assembly 43, and the top part of the pressing rod is pressed to move the pressing rod downward. The sleeve is provided with an elastic member such as a spring, and the side surface of the pressing rod is formed with a protrusion. When the pressing rod moves downward, the protrusion compresses the elastic member, so that the elastic member is elastically deformed, so that the pressing rod can be reset after the pressing rod is released, facilitating the sticking action of the subsequent strain gauge.

[0074] Specifically, as shown in FIG. 4, the positioning and sticking assembly 44 comprises a positioning and sticking plate 441 and a plurality of strain gauges 442, wherein the positioning and sticking plate 441 is provided with a plurality of through holes 4411 corresponding to the strain gauges 442, and the strain gauges 442 are arranged in the through holes 4411. Figure 8 and Figure 10As shown, the positioning and pasting assembly 44 comprises a positioning plate 441 for connecting the strain gauge and a transversely elongated rod 442, the positioning plate 441 is mounted on the end of the transversely elongated rod 442 away from the transmission assembly 43. In order to ensure that the vertical movement of the pressing member 42 can be effectively converted into the transverse movement of the positioning and pasting assembly 44, the transmission assembly 43 comprises a vertical rack 431, a transverse rack 432 and a transmission gear set 433, wherein the vertical rack 431 is connected to the protruding end of the pressing member 42, the transverse rack 432 is connected to the end of the transversely elongated rod 442 towards the transmission assembly 43, and the vertical rack 431 and the transverse rack 432 are in driving connection with the transmission gear set 433. Specifically, the transmission gear set 433 can be three spur gears in meshing transmission, wherein the first spur gear is in meshing transmission with the vertical rack 431, the third spur gear is in meshing transmission with the transverse rack 432, and the second spur gear is in meshing transmission with the first spur gear and the third spur gear at the same time.

[0075] Further, when the pressing member 42 is driven to move downward, the protruding end of the pressing member 42 drives the vertical rack 431 to move downward, which in turn drives the transmission gear set 433 to rotate in meshing transmission. Under the driving action of the transmission gear set 433, the transverse rack 432 drives the transversely elongated rod 442 and the positioning plate 441 to move towards the hollow structure test piece, so as to realize the movement of the strain gauge towards the hollow structure test piece and the pasting of the strain gauge on the hollow structure test piece, and complete the pasting action of the hollow structure test piece. By using the meshing transmission of the transmission gear set 433, it is ensured that the transversely elongated rod 442 can provide a pasting pressure perpendicular to the inner wall surface of the test piece for the positioning plate 441 and the strain gauge, so as to effectively ensure the success rate and pasting stability of the strain gauge pasted on the inner wall surface of the hollow structure test piece.

[0076] Further, as shown in the drawings, Figure 9 The positioning plate 441 is provided with a linkage rod 443, the middle part of the linkage rod 443 is rotatably connected to the positioning plate 441, one end of the linkage rod 443 is connected with a first movable block 444, and the other end of the linkage rod 443 is connected with a second movable block 446, so that a lever structure is formed between the first movable block 444 and the second movable block 446. The first movable block 444 is formed with an embedding groove 445, and the strain gauge can be embedded in the embedding groove 445, so as to ensure that the strain gauge moves with the first movable block 444. The first movable block 444 and the second movable block 446 are both slidingly connected to the positioning plate 441, and the length of the first movable block 444 is greater than the length of the second movable block 446, and the second movable block 446 is located inside the embedding groove 445.

[0077] Further, when the positioning plate 441 drives the first movable block 444 and the second movable block 446 to move towards the inner wall surface of the hollow structure test piece, the first movable block 444 can abut against the inner wall surface of the hollow structure test piece earlier than the second movable block 446, and under the extrusion of the inner wall surface of the hollow structure test piece, the first movable block 444 moves away from the inner wall surface of the hollow structure test piece, while under the action of the linkage rod 443, the second movable block 446 moves towards the inner wall surface of the hollow structure test piece, pushes the strain gauge out of the embedding groove 445, and is pasted on the inner wall surface of the hollow structure test piece, thereby completing the pasting action of the strain gauge and ensuring the uniformity of the pasting pressure of the strain gauge by lever transmission.

[0078] It should be noted that, as shown in Figure 9 The first movable block 444 and the positioning plate 441 wall surface are provided with a resilient member 447, which is preferably a compression spring, to push the first movable block 444 out of reset when the positioning plate 441 moves away from the inner wall surface of the hollow structure test piece, and at the same time, the second movable block 446 moves back to the inside of the embedding groove 445, so as to facilitate the subsequent pasting action of the strain gauge.

[0079] It should be further noted that the positioning plate 441 is also provided with a protrusion 448, and the protrusion 448 is provided with a buckle hole 449, and after the strain gauge is embedded in the embedding groove 445, the lead wire of the strain gauge can pass through the buckle hole 449 to ensure the stability of the installation of the strain gauge.

[0080] In addition, it should be noted that the strain gauge needs to be pasted at different depths of the inner wall surface of the hollow structure test piece, so as to test and study the stress of the inner wall surface of the hollow structure test piece at different depths. In this embodiment, as shown in Figure 7 The positioning disc 41 is provided with a telescopic member 411, and the extension end of the telescopic member 411 is connected to the transmission assembly 43, and when it is necessary to adjust the preset depth of the pasting of the strain gauge, the extension length of the telescopic member 411 is adjusted to adjust the relative distance between the transmission assembly 43 and the positioning disc 41, thereby adjusting the pasting depth of the strain gauge.

[0081] Preferably, the telescopic member 411 is two adjusting screws, one end of one adjusting screw is connected to the positioning disc 41, and the other end of the other adjusting screw is threadedly connected to the one adjusting screw, and the transmission assembly 43 is also provided with a transmission box, and the transmission box is formed with a connecting block, and the lower end of the other adjusting screw is threadedly connected to the connecting block, and by adjusting the extension lengths of the two adjusting screws, the relative distance between the transmission assembly 43 and the positioning disc 41 is adjusted, thereby adjusting the pasting depth of the strain gauge.

[0082] It should be noted that the transmission box has vertical and horizontal grooves inside. The vertical rack 431 is slidably connected to the vertical groove, and the horizontal rack 432 is slidably connected to the horizontal groove. The top and bottom of the transmission box have coaxial through holes. The pressing rod passes through the through holes into the transmission box and connects with the connecting protrusion 448 on the back of the vertical groove, so that the pressing rod can press the vertical groove to complete the motion transmission between the vertical rack 431 and the horizontal rack 432.

[0083] Accordingly, a second aspect of the present invention provides a method for preparing a reinforced hollow structure specimen, wherein the method for preparing a reinforced hollow structure specimen is based on the apparatus for preparing a reinforced hollow structure specimen as described in any one of the above claims. Figure 11 As shown, the method for preparing reinforced hollow structure specimens includes the following steps:

[0084] Step S1: Based on the specimen size parameters, the inner core mold 21 is placed on the base 1, the inner core mold 21 is inflated, and a release layer is covered on the outer side wall of the inner core mold 21.

[0085] Step S2: Place the specimen reinforcement 5 on the side of the inner core mold 21, and use the positioning component 3 to determine the spatial position of the specimen reinforcement 5, thus completing the positioning and fixing of the specimen reinforcement 5.

[0086] Step S3: Cover the inner wall surface of the first outer mold 22 and the inner wall surface of the second outer mold 23 with a demolding layer, enclose the specimen reinforcement 5 with the first outer mold 22 and the second outer mold 23, and seal the closed surface 223 of the first outer mold 22 and the second outer mold 23.

[0087] Step S4: Pour concrete into the sample preparation area between the inner core mold 21 and the first outer mold 22 and the second outer mold 23 to prepare the specimen.

[0088] Step S5: After confirming that the specimen has initially hardened, release the positioning component 3 and lift the positioning component 3, and then perform additional pouring on the specimen to fill the hole above the specimen.

[0089] Step S6: Determine that the specimen has reached the preset strength, release the first outer mold 22 and the second outer mold 23, and release the internal gas of the inner core mold 21 to complete the specimen preparation.

[0090] Specifically, to ensure the positioning and fixation of the reinforcement 5 of the specimen in the sample preparation area, step S2 includes:

[0091] Step S21: Using the sleeve hole 351 of the first connecting rod 35, place the support 31 on top of the first outer mold 22 and the second outer mold 23, and fit the positioning ring 34 onto the inner core mold 21.

[0092] Step S22: Adjust the relative distance between the positioning member 33 and the specimen reinforcement 5, and connect the positioning member 33 and the specimen reinforcement 5.

[0093] Step S23, adjust the extension length of the adjusting member 32 in the positioning ring 34, control the spatial position of the test reinforcement 5 in the sample preparation area, and ensure that the test reinforcement 5 is arranged vertically.

[0094] Step S24, power on the magnetic attraction member 332 in the positioning member 33, and use the magnetism of the magnetic attraction member 332 to fix the test reinforcement 5.

[0095] In this embodiment, when the hollow structure test piece is prepared, the test reinforcement 5 can be assembled on the outer surface of the inner core mold 21, then the positioning ring 34 is sleeved on the outer wall surface of the inner core mold 21, and the positioning member 33 is connected with the test reinforcement 5 by adjusting the position of the adjusting member 32. At this time, each adjusting member 32 can be finely adjusted to adjust the relative distance between the positioning member 33 and the test reinforcement 5, so that the test reinforcement 5 remains vertical under the cooperation of the adjusting member 32 and the positioning member 33, and the relative distance between the test reinforcement 5 and the outer surface of the inner core mold 21 is ensured to be constant, thereby completing the positioning of the test reinforcement 5 in the sample preparation area.

[0096] Then, the first outer mold 22 is rotated to cover the second outer mold 23, and the test reinforcement 5 and the inner core mold 21 are surrounded by the first outer mold 22 and the second outer mold 23, so as to pour concrete in the sample preparation area between the inner core mold 21 and the first outer mold 22 and the second outer mold 23, and correspondingly complete the preparation of the hollow structure test piece.

[0097] Therefore, in this embodiment, the positioning ring 34 can use the outer surface of the inner core mold 21 as a positioning reference, and the cooperation of the adjusting member 32 and the positioning member 33 can complete the positioning and fixing of the test reinforcement 5 in the sample preparation area, which can ensure the spatial position precision between the test reinforcement 5 and the inner core mold 21, the first outer mold 22 and the second outer mold 23, effectively ensure the uniformity of the test piece protective layer thickness after pouring concrete, effectively ensure the forming quality of the hollow structure test piece, and thereby improve the research accuracy of the stress performance research result of the hollow structure test piece.

[0098] Further, in order to facilitate subsequent experimental research on the internal mechanical behavior of the hollow structure test piece under complex load, strain gauges are usually pasted on the inner wall surface of the hollow structure test piece. In order to improve the efficiency of pasting strain gauges on the inner wall surface of the hollow structure test piece, after step S6, the method further comprises:

[0099] Step S7, pasting strain gauges on the inner hole wall surface of the test piece by using the strain gauge pasting component 4.

[0100] Specifically, when the strain gauge is pasted, the positioning disc 41 can be arranged on the top surface of the hollow structure test piece, and the pressing piece 42, the transmission assembly 43 and the positioning and pasting assembly 44 are extended into the internal hollow cavity of the hollow structure test piece. At this time, the distance between the transmission assembly 43 and the positioning disc 41 can be adjusted, so that the positioning and pasting assembly 44 on which the strain gauge is installed is moved to a preset depth, and the preset depth is the depth of the hollow structure test piece where the strain gauge needs to be installed. Then, the pressing piece 42 can be used, when the pressing piece 42 is driven to move downward, the extending end of the pressing piece 42 drives the vertical rack 431 to move downward, which in turn drives the transmission gear set 433 to rotate. Under the transmission of the transmission gear set 433, the horizontal rack 432 drives the horizontal extension rod 442 and the positioning plate 441 to move towards the hollow structure test piece, so as to realize the movement of the strain gauge to the hollow structure test piece and the pasting of the strain gauge on the hollow structure test piece, and complete the pasting action of the hollow structure test piece. The engagement transmission of the transmission gear set 433 ensures that the horizontal extension rod 442 can provide the positioning plate 441 and the strain gauge with a pasting pressure perpendicular to the inner wall surface of the test piece, effectively ensuring the success rate and pasting stability of the pasting of the strain gauge on the inner wall surface of the hollow structure test piece.

[0101] The above is the preferred embodiment of the present application. It should be noted that those skilled in the art can make several improvements and refinements without departing from the principles of the present application, and these improvements and refinements are also considered within the protection scope of the present application.

Claims

1. A sample preparation device for reinforced hollow structural specimens, characterized in that, The sample includes a base, a sample mold component, and a positioning component. The sample mold component includes an inner core mold, a first outer mold, and a second outer mold. The inner core mold is disposed on the base. At least one of the first outer mold and the second outer mold is rotatably connected to the base. The first outer mold rotatably covers the second outer mold, and a sample preparation area is formed between the inner core mold, the first outer mold, and the second outer mold. The positioning component includes a support member, multiple adjusting members, and multiple positioning members. The support member is connected to the top plate of the first outer mold and the second outer mold. The support member forms a positioning ring, which is sleeved on the outer wall of the inner core mold. The multiple adjusting members are arranged around the positioning ring, and each adjusting member is connected to a positioning member. The adjusting members are used to adjust the relative distance between the positioning member and the specimen reinforcement, and to connect the positioning member to the specimen reinforcement.

2. The apparatus for preparing reinforced hollow structural specimens as described in claim 1, characterized in that, The positioning member has a positioning groove on the bottom surface facing the reinforcement of the specimen. A magnetic suction member is provided on the inner wall of the positioning groove. The base is provided with an electric magnetic suction device. The magnetic suction member is electrically connected to the electric magnetic suction device.

3. The sample preparation device for reinforced hollow structure specimens as described in claim 1, characterized in that, The base has a vertical pole, and the first outer mold and the second outer mold are rotatably connected to the vertical pole; the positioning ring has a first connecting rod, and a sleeve hole is formed at one end of the first connecting rod facing the vertical pole, through which the first connecting rod is sleeved onto the vertical pole. A connecting groove is formed at the bottom of the sleeve hole, and a limiting block is formed on the upright, with the connecting groove embedded in the limiting block.

4. The sample preparation device for reinforced hollow structural specimens as described in claim 3, characterized in that, The inner core mold is an inflatable inner mold, and the inner core mold has an air injection port and an air exhaust port. The base is provided with an inflation device, and the air injection port and the air exhaust port are both connected to the inflation device. Both the first outer mold and the second outer mold have a shell and a second connecting rod. The shell is rotatably connected to the upright through the second connecting rod. The shell has a closed surface. When the first outer mold rotates to cover the second outer mold, the closed surface of the first outer mold abuts against the closed surface of the second outer mold. The closed surface is provided with a sealing element.

5. The sample preparation device for reinforced hollow structural specimens as described in claim 1, characterized in that, It also includes a strain gauge bonding component, which comprises a positioning plate, a pressing component, a transmission assembly, and a positioning bonding assembly; The positioning plate is mounted on the base, the pressing member is connected to the positioning plate, the protruding end of the pressing member is connected to the transmission assembly, the transmission assembly is drivenly connected to the positioning adhesive assembly, and the pressing member is adapted to switch between a pressing state and a lifting state. In the pressing state, the pressing member moves downward, causing the positioning adhesive assembly to move laterally away from the transmission assembly. In the lifting state, the pressing member moves upward, causing the positioning adhesive assembly to move laterally closer to the transmission assembly.

6. The sample preparation device for reinforced hollow structural specimens as described in claim 5, characterized in that, The positioning and bonding assembly includes a positioning plate for connecting the strain gauge and a transverse extension rod, wherein the positioning plate is mounted on the end of the transverse extension rod away from the transmission assembly; The transmission assembly includes a vertical rack, a horizontal rack, and a transmission gear set, wherein the vertical rack is connected to the extended end of the pressing member, the horizontal rack is connected to the end of the horizontal extension rod facing the transmission assembly, and both the vertical rack and the horizontal rack are connected to the transmission gear set for transmission.

7. The sample preparation device for reinforced hollow structure specimens as described in claim 6, characterized in that, A linkage rod is provided inside the positioning plate. The middle part of the linkage rod is rotatably connected to the positioning plate. One end of the linkage rod is connected to a first movable block, which forms an insert groove. The other end of the linkage rod is connected to a second movable block. Both the first and second movable blocks are slidably connected to the positioning plate. The length of the first movable block is greater than the length of the second movable block. The second movable block is located inside the insert groove.

8. A method for preparing reinforced hollow structural specimens, characterized in that, The method for preparing reinforced hollow structure specimens, based on the apparatus for preparing reinforced hollow structure specimens according to any one of claims 1 to 7, includes the following steps: Based on the specimen size parameters, the inner core mold is placed on the base, the inner core mold is inflated, and a release layer is covered on the outer side wall of the inner core mold. The specimen reinforcement is fitted onto the side of the inner core mold, and the spatial position of the specimen reinforcement is determined by the positioning component, thus completing the positioning and fixing of the specimen reinforcement. A release layer is applied to the inner wall surfaces of the first outer mold and the second outer mold. The first outer mold and the second outer mold are used to enclose the specimen and reinforce it. The closed surfaces of the first outer mold and the second outer mold are then sealed. Concrete was poured into the sample preparation area between the inner core mold and the first and second outer molds to prepare specimens. Once the specimen has been preliminarily hardened, the positioning component is released and lifted, and additional casting is performed on the specimen to fill the holes above the specimen. Once the specimen has reached the preset strength, the first outer mold and the second outer mold are removed, and the internal gas of the inner core mold is released, thus completing the specimen preparation.

9. The method for preparing reinforced hollow structural specimens as described in claim 8, characterized in that, The step of using positioning components to determine the spatial position of the reinforcement in the specimen, and to complete the positioning and fixing of the reinforcement in the specimen, includes: The support is placed on top of the first outer mold and the second outer mold using the sleeve hole of the first connecting rod, and the positioning ring is sleeved on the inner core mold. Adjust the relative distance between the positioning component and the reinforcement of the specimen, and connect the positioning component to the reinforcement of the specimen; Adjusting the extension length of the adjusting member on the positioning ring controls the spatial position of the specimen reinforcement in the sample preparation area and ensures that the specimen reinforcement is arranged vertically; The magnetic chuck inside the positioning component is energized, and the magnetic properties of the magnetic chuck are used to fix the reinforcement of the specimen.

10. The method for preparing reinforced hollow structural specimens as described in claim 8, characterized in that, After the steps of releasing the first outer mold and the second outer mold, releasing the internal gas of the inner core mold, and completing the specimen preparation, the method further includes: The strain gauge is attached to the inner wall of the specimen using a strain gauge attachment component.

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