Dynamic mechanical testing device and testing method for reinforced concrete adhesive interface

Abstract

The application provides a dynamic mechanical testing device and testing method for a reinforced concrete bonding interface, and relates to the field of reinforced concrete testing. The device clamps the reinforced concrete to-be-tested piece horizontally, and the three-prism in the clamp stretches the to-be-tested piece under the action of the horizontal loading force of the incident rod, so that the dynamic mechanical testing result of the bonding interface between the reinforced concrete and the to-be-tested piece is obtained. The to-be-tested piece and the clamp are designed according to the Saint-Venant principle, the coupling between the structural response of the to-be-tested piece and the interface material response is eliminated, the problem that the interface testing result is coupled with the structural response of the to-be-tested piece in the existing bonding strength testing of the reinforced concrete interface is solved, and the bonding strength testing precision of the reinforced concrete interface is higher.

Description

Technical Field

[0001] The present invention relates to the field of reinforced concrete testing, and in particular to a dynamic mechanical testing device and a testing method for a reinforced concrete bonding interface. Background Art

[0002] The bond strength at the interface between steel and concrete is one of the most important properties of reinforced concrete structures. Due to the uncoordinated deformation of the steel and concrete materials and the lower strength of the interface bond strength than the steel and concrete materials, slip failure of the bond interface often occurs first under dynamic loads, which is a major cause of failure of reinforced concrete structures. Therefore, studying the dynamic mechanical properties of the bond interface is of great significance for revealing the failure mechanism of reinforced concrete structures. In the existing technology, the test results of the bond strength test of the reinforced concrete interface are coupled with the structural response of the test piece, resulting in insufficient accuracy of the reinforced concrete interface bond strength test. Summary of the Invention

[0003] In view of this, the purpose of the present invention is to provide a dynamic mechanical testing device and testing method for the bond interface of reinforced concrete, wherein the reinforced concrete test piece to be tested is horizontally supported by a fixture in the testing device, and the test piece is stretched by the triangular prism in the fixture under the action of the horizontal loading force applied by the incident rod, thereby obtaining the dynamic mechanical test results of the bond interface between the steel bar and concrete in the test piece; the scheme uses the Saint-Venant principle to design the size of the test piece and the fixture, decoupling the structural response of the test piece and the interface material response, solving the problem of coupling between the interface test results and the structural response of the test piece in the existing reinforced concrete interface bond strength test, and making the reinforced concrete interface bond strength test more accurate.

[0004] In a first aspect, an embodiment of the present invention provides a dynamic mechanical testing device for a steel-concrete bonding interface, the device comprising: an incident rod, a fixture, a restraining device, and a transmission rod; a test piece consisting of steel bars and concrete is disposed in the restraining device; the steel bars in the test piece pass through and are fixed in the concrete;

[0005] The incident rod and the transmission rod are symmetrically arranged Hopkinson rods, the incident rod is used to apply the loading force, and the transmission rod is used to bear the loading force;

[0006] The fixture includes two symmetrical holding devices, each of which includes a sleeve and a triangular prism; wherein the first joint portion of the sleeve contacts the incident rod and the transmission rod respectively; the second joint portion of the sleeve contacts the quadrilateral bottom surface of the triangular prism; the two triangular parallel faces of the triangular prism are parallel to the axis of the steel bar; and the two quadrilateral side faces of the triangular prism are both in contact with the restraining device;

[0007] The restraint device comprises two symmetrical restraint components, each of which is provided with restraint holes; the steel bars in the test piece pass through the restraint holes.

[0008] In one embodiment, the test piece includes: a first concrete piece, a second concrete piece, and a steel bar; the first concrete piece and the second concrete piece are identical hollow cylindrical concrete pieces;

[0009] The first concrete member and the second concrete member are respectively disposed at both ends of the steel bar.

[0010] In one embodiment, the steel bar has a diameter of 6 mm and a length of 110 mm;

[0011] The first and second concrete members have a height of 50 mm, an outer diameter of 66 mm, and an inner diameter of 6 mm;

[0012] The steel bars are fixed at the cylindrical axis of the first concrete member and the second concrete member respectively; the steel bars pass through the top surfaces of the first concrete member and the second concrete member respectively; and both ends of the steel bars are located 20 mm away from the bottom surfaces of the first concrete member and the second concrete member respectively.

[0013] In one embodiment, the sleeve in the holding device is a cylindrical sleeve;

[0014] The inner bottom surface of the cylindrical sleeve is the first joint portion of the sleeve;

[0015] The outer bottom surface of the cylindrical sleeve is the second joint portion of the sleeve;

[0016] The area of ​​the second connecting portion is greater than the area of ​​the quadrilateral bottom surface of the triangular prism.

[0017] In one embodiment, the triangular face of the triangular prism in the holding device is an isosceles triangle; the height of the isosceles triangle is not less than 60 mm; and the vertex angle of the triangular prism is 45-60 degrees.

[0018] In one embodiment, the restraining component in the restraining device includes a protruding portion and a fixing portion; the fixing portion is a rectangular parallelepiped steel plate, the restraining hole is arranged at the symmetry axis of the fixing portion, and the diameter of the restraining hole is larger than the diameter of the steel bar;

[0019] The protrusions are arranged on both sides of the fixing portion, and the protrusions are connected to two quadrilateral side surfaces of the triangular prism.

[0020] In one embodiment, the spacing between the protrusions of the two symmetrical restraining members is 20 mm;

[0021] A chamfered area is provided in the protruding portion, where the chamfered area is connected to two quadrilateral side surfaces of the triangular prism.

[0022] In a second aspect, an embodiment of the present invention further provides a dynamic mechanical testing method for a reinforced concrete bond interface. The method is applied to the dynamic mechanical testing device for a reinforced concrete bond interface mentioned in the first aspect, and the method comprises:

[0023] Fix the test piece in the restraint device and place the triangular prism of the fixture between the restraint devices;

[0024] Control the incident rod to apply loading force to the fixture and obtain the mechanical characteristic curve between the restraint device and the workpiece in real time;

[0025] The dynamic mechanical test results of the bonding interface between the steel bar and concrete in the test piece are determined based on the mechanical characteristic curve.

[0026] In one embodiment, the step of controlling the incident rod to apply a loading force to the fixture and obtaining a mechanical characteristic curve between the restraint device and the workpiece in real time includes:

[0027] The strain gauge pre-attached to the incident rod is used to obtain the strain data of the Hopkinson bar in real time, and the loading force is determined based on the strain data;

[0028] After controlling the incident rod to apply a loading force to the fixture, the first acting force between the triangular prism and the incident rod is obtained in real time;

[0029] Determining a second force between the holding device and the restraining device using the first force;

[0030] A mechanical characteristic curve between the restraint device and the workpiece to be measured is generated according to the second acting force.

[0031] In one embodiment, the step of determining the dynamic mechanical test results of the bonding interface between the steel bar and the concrete in the test piece according to the mechanical characteristic curve includes:

[0032] Obtain strain data from mechanical characteristic curves;

[0033] The strain data is used to calculate the force at the bond interface between the steel bar and concrete in the test piece. The force at the bond interface between the steel bar and concrete is calculated using the following formula:

[0034]

[0035] Among them, F te (t) is the force between the bond interface of steel bar and concrete that changes with time t; ε(t) is the strain data of the incident rod that changes with time t; A is the cross-sectional area of ​​the incident rod; E is the elastic modulus; β is the vertex angle of the triangle in the parallel plane of the triangular prism;

[0036] The dynamic mechanical test results are determined based on the forces acting at the bond interface between the steel bars and concrete.

[0037] In a third aspect, an embodiment of the present invention further provides an electronic device comprising a processor and a memory, wherein the memory stores computer-executable instructions that can be executed by the processor, and the processor executes the computer-executable instructions to implement the dynamic mechanical testing method for the reinforced concrete bonding interface mentioned in the second aspect.

[0038] In a fourth aspect, an embodiment of the present invention further provides a computer-readable storage medium, which stores computer-executable instructions. When the computer-executable instructions are called and executed by a processor, the computer-executable instructions prompt the processor to implement the dynamic mechanical testing method of the reinforced concrete bonding interface mentioned in the second aspect.

[0039] The embodiments of the present invention bring at least the following beneficial effects:

[0040] The present invention provides a dynamic mechanical testing device and testing method for a reinforced concrete bonding interface. The device comprises: an incident rod, a clamp, a constraint device, and a transmission rod; a test piece consisting of a steel bar and concrete is arranged in the constraint device; the steel bar in the test piece passes through and is fixed in the concrete; the incident rod and the transmission rod are symmetrically arranged Hopkinson rods, the incident rod is used to apply a loading force, and the transmission rod is used to bear the loading force; the clamp comprises two symmetrical holding devices, and the holding devices comprise a sleeve and a triangular prism; wherein a first joint portion of the sleeve contacts the incident rod and the transmission rod respectively; a second joint portion of the sleeve contacts the quadrilateral bottom surface of the triangular prism; two triangular parallel surfaces of the triangular prism are parallel to the axial direction of the steel bar; two quadrilateral side surfaces of the triangular prism both contact the constraint device; the constraint device comprises two symmetrical constraint components, each of which is provided with a constraint hole; and the steel bar in the test piece passes through the constraint hole. This test scheme uses the fixture in the test device to horizontally support the reinforced concrete test piece, and stretches the test piece through the triangular prism in the fixture under the action of the horizontal loading force applied by the incident rod, thereby obtaining the dynamic mechanical test results of the bonding interface between the steel bars and concrete in the test piece; this scheme uses the Saint-Venant principle to design the dimensions of the test piece and the fixture, decoupling the structural response of the test piece and the interface material response, and solving the problem of coupling between the interface test results and the structural response of the test piece in the existing reinforced concrete interface bond strength test, making the reinforced concrete interface bond strength test more accurate. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 A schematic structural diagram of a dynamic mechanical testing device for a reinforced concrete bonding interface provided by an embodiment of the present invention;

[0042] Figure 2 A schematic structural diagram of a test piece in a dynamic mechanical testing device for a reinforced concrete bonding interface provided by an embodiment of the present invention;

[0043] Figure 3 A schematic structural diagram of a supporting device in a dynamic mechanical testing device for a reinforced concrete bonding interface provided by an embodiment of the present invention;

[0044] Figure 4 A schematic structural diagram of a restraint device in a dynamic mechanical testing device for a reinforced concrete bonding interface provided by an embodiment of the present invention;

[0045] Figure 5 A schematic structural diagram of another dynamic mechanical testing device for reinforced concrete bonding interfaces provided by an embodiment of the present invention;

[0046] Figure 6 A flow chart of a dynamic mechanical testing method for a reinforced concrete bonding interface provided by an embodiment of the present invention;

[0047] Figure 7 A flowchart of step S602 of controlling an incident rod to apply a loading force to a fixture and obtaining a mechanical characteristic curve between a restraining device and a test piece in real time in a dynamic mechanical testing method for a reinforced concrete bonding interface provided by an embodiment of the present invention;

[0048] Figure 8 A flowchart of step S603 of determining the dynamic mechanical test results of the bonding interface between steel bars and concrete in a test piece according to a mechanical characteristic curve in a dynamic mechanical testing method for a steel bar-concrete bonding interface provided by an embodiment of the present invention;

[0049] Figure 9 A force analysis diagram between a triangular prism and a protruding portion of a restraint device in a dynamic mechanical testing method for a reinforced concrete bonding interface provided by an embodiment of the present invention;

[0050] Figure 10 A force analysis diagram between a restraining device and a test piece in a dynamic mechanical testing method for a reinforced concrete bonding interface provided by an embodiment of the present invention;

[0051] Figure 11 A force analysis diagram between the steel bars inside the test piece and the reinforced concrete interface in a dynamic mechanical testing method for a reinforced concrete bonding interface provided by an embodiment of the present invention;

[0052] Figure 12 A schematic structural diagram of an electronic device provided by an embodiment of the present invention.

[0053] icon:

[0054] 10-incident rod;

[0055] 20- fixture; 21- holding device; 22- sleeve; 23- triangular prism;

[0056] 30 - restraint device; 31 - restraint member; 32 - restraint hole; 33 - protrusion; 34 - fixing portion;

[0057] 40 - transmission rod;

[0058] 50 - test piece; 51 - steel bar; 52 - concrete; 52a - first concrete piece; 52b - second concrete piece;

[0059] 101 - processor; 102 - memory; 103 - bus; 104 - communication interface. DETAILED DESCRIPTION

[0060] In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions of the present application will be described below in connection with the embodiments. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the protection scope of the present application.

[0061] The bond strength of the steel bar and concrete interface is one of the most important properties of the reinforced concrete structure. Since the steel bar and concrete material deformation is not coordinated and the interface bond strength is lower than the strength of the steel bar and concrete material, the bond interface slip failure often occurs first under the action of dynamic load, which is an important reason for the failure of the reinforced concrete structure. Therefore, it is of great significance to study the dynamic mechanical properties of the bond interface for revealing the failure mechanism of the reinforced concrete structure. In the prior art, the test results of the bond strength of the reinforced concrete interface are coupled with the structural response of the test piece, resulting in insufficient test precision of the bond strength of the reinforced concrete interface. Based on this, the dynamic mechanical test device and test method for the bond interface of the reinforced concrete provided by the embodiments of the present application, the test piece of the reinforced concrete is horizontally clamped by the clamp in the test device, and the test piece is stretched by the three-prism in the clamp under the action of the horizontal loading force applied by the incident rod, so as to obtain the dynamic mechanical test results of the bond interface between the steel bar and the concrete in the test piece. The present application uses the Saint-Venant principle to design the size of the test piece and the clamp, and solves the coupling of the structural response of the test piece and the interface material response, solves the problem of the coupling of the interface test results and the structural response of the test piece in the existing bond strength test of the reinforced concrete interface, and makes the bond strength test precision of the reinforced concrete interface higher.

[0062] In order to facilitate the understanding of the present embodiment, first, a dynamic mechanical test device for the bond interface of the reinforced concrete disclosed by the embodiments of the present application will be described in detail, as follows: Figure 1As shown, the dynamic mechanical testing device for the reinforced concrete bonding interface includes: an incident rod 10, a clamp 20, a restraining device 30, and a transmission rod 40; a test piece 50 consisting of a steel bar 51 and concrete 52 is set in the restraining device 30; the steel bar 51 in the test piece 50 passes through and is fixed in the concrete 52.

[0063] The incident rod 10 and the transmission rod 40 are symmetrically arranged Hopkinson rods. The incident rod 10 is used to apply the loading force, and the transmission rod 40 is used to bear the loading force.

[0064] The clamp 20 includes two symmetrical holding devices 21, which include a sleeve 22 and a triangular prism 23; wherein the first joint portion of the sleeve 22 contacts the incident rod 10; the second joint portion of the sleeve 22 contacts the quadrilateral bottom surface of the triangular prism 23; the two triangular parallel surfaces of the triangular prism 23 are parallel to the axial direction of the steel bar 51; and the two quadrilateral side surfaces of the triangular prism 23 are both in contact with the restraint device 30.

[0065] The restraining device 30 includes two symmetrical restraining components 31 , each of which is provided with a restraining hole 32 ; the steel bars 51 in the test piece 50 pass through the restraining hole 32 .

[0066] During the dynamic mechanical testing of the reinforced concrete bonding interface, the testing device first produces a test piece 50 containing a steel bar 51 and concrete 52. The steel bar 51 in the test piece 50 passes through the concrete 52. After the concrete 52 solidifies, it forms a bonding interface with the steel bar 51. The testing device then tests the dynamic mechanical properties of this bonding interface.

[0067] The test piece 50 is set in the restraint device 30, and the steel bar 51 in the test piece 50 passes through the restraint hole 32. The triangular prism 23 in the clamp 20 transmits the loading force applied by the incident rod 10 to the restraint device 30, and applies the loading force to the concrete 52 through the restraint device 30, thereby stretching the concrete 52, and the dynamic mechanical properties of the bonding interface between the steel bar 51 and the concrete 52 can be tested.

[0068] In one embodiment, the test piece 50 is dumbbell-shaped, specifically Figure 2 As shown, the test piece 50 at this time includes: a first concrete piece 52a, a second concrete piece 52b and a steel bar 51; the first concrete piece 52a and the second concrete piece 52b are the same hollow cylindrical concrete pieces; the first concrete piece 52a and the second concrete piece 52b are respectively arranged at both ends of the steel bar 51.

[0069] In one embodiment, the rebar 51 has a diameter of 6 mm and a length of 110 mm. The first and second concrete members 52a, 52b have a height of 50 mm, an outer diameter of 66 mm, and an inner diameter of 6 mm. The rebar 51 is secured to the cylindrical axis of each of the first and second concrete members 52a, 52b. The rebar 51 passes through the top surfaces of each of the first and second concrete members 52a, 52b, respectively. The ends of the rebar 51 are located 20 mm from the bottom surfaces of each of the first and second concrete members 52a, 52b.

[0070] During the fabrication of the test piece 50, a rebar 51 with a diameter of 6 mm and a length of 110 mm was prepared. Two concrete cylinders, a first concrete element 52a and a second concrete element 52b, were cast at either end of the rebar 51, with the axis of the rebar 51 as the center. These cylinders each measured 50 mm in height, 66 mm in outer diameter, and 6 mm in inner diameter. The rebar 51 was embedded in the concrete cylinder to a depth of 30 mm on one side, with a 20 mm hollow section extending along the axis of the concrete cylinder. After the concrete solidified and cured, a bonding interface was formed between the embedded portion of the rebar and the concrete.

[0071] After the test piece 50 is manufactured, it is supported by the fixture 20. Figure 3 As shown, in one embodiment, the sleeve 22 in the holding device 21 is a cylindrical sleeve; the inner bottom surface of the sleeve 22 is the first coupling portion of the sleeve 22; the outer bottom surface of the sleeve 22 is the second coupling portion of the sleeve; the area of ​​the second coupling portion is greater than the area of ​​the quadrilateral bottom surface of the triangular prism.

[0072] In one embodiment, the triangular faces of the triangular prism 23 in the holding device 21 are isosceles triangles; the height of the triangular prism 23 is not less than 60 mm; and the vertex angle of the triangular prism 23 is 45-60 degrees.

[0073] At this time, the sleeve 22 has two main functions: the first is to fit the fixture 20 onto the end face of the incident rod 10, and the second is to use the triangular prism 23 to transmit the force provided by the Hopkinson bar to the restraining device 30. The triangular cross-section of the triangular prism 23 is an isosceles triangle, wherein the two base angles are welded to the outer bottom surface of the sleeve 22. The angle of the triangle's apex determines the efficiency of converting the pressure provided by the Hopkinson bar into the dynamic tensile force of the bonding interface of the test piece 50. This angle should not be too large or too small. If the angle is too small, the conversion efficiency is low; if the angle is too large, the conversion efficiency is too high, which easily exceeds the compressive strength of the concrete material, causing some concrete to break before the bonding section slips. Therefore, the apex angle is set to between 45-60°. The height of the isosceles triangle is set to ensure that the protrusion of the restraining device does not contact the outer bottom surface of the sleeve during the entire loading process of the test piece. The height of the isosceles triangle (i.e., the protrusion height of the triangular prism) should not be less than 60mm.

[0074] The restraining device 30 does not need to wrap the test piece 50, and can be set between the first concrete piece 52a and the second concrete piece 52b in the dumbbell-shaped test piece 50. Figure 4 As shown, in one embodiment, the restraining component 31 in the restraining device 30 includes a protruding portion 33 and a fixing portion 34; the fixing portion 34 is a rectangular parallelepiped steel plate, the restraining hole 32 is arranged at the symmetry axis of the fixing portion 34, and the diameter of the restraining hole 32 is larger than the diameter of the steel bar 51;

[0075] The protrusions 33 are provided on both sides of the fixing portion 34 , where the protrusions 33 meet the two quadrilateral side surfaces of the triangular prism 23 .

[0076] In one embodiment, the height between the protrusions of the two symmetrical restraining parts 31 is 20 mm; a chamfered area is provided in the protrusion 33, and the chamfered area connects with the two quadrilateral sides of the triangular prism 23 to reduce the friction at the contact position.

[0077] The restraining component 31 in the restraining device 30 is two separate U-shaped steel plates (blocks), with a circular hole with a diameter greater than 6 mm in the center of the top, so that the steel bar 51 of the test piece 50 can pass through the restraining device 30 smoothly. The restraining device 30 needs to be inserted into the middle of the steel bar 51 and the concrete 52 before pouring the concrete. The restraining component 31 is a square steel plate with a circular hole in the center, and the length of its top side needs to be greater than the outer diameter of the concrete 52. In the vertical direction, the height of the restraining component 31 needs to match the size parameters of the triangular prism 23. According to the length between the first concrete piece 52a and the second concrete piece 52b, the height of the protrusion 33 of the restraining component 31 in the restraining device 30 can be 20 mm. The contact part of the protrusion 33 of the restraining component 31 and the triangular prism 23 is chamfered to minimize the friction between the two.

[0078] like Figure 5 The figure shows a structural schematic diagram of another dynamic mechanical testing device for the bond interface of reinforced concrete, which is a three-dimensional stereoscopic diagram of the dynamic mechanical testing device for the bond interface of reinforced concrete.

[0079] Figure 5 It is clearly shown in the figure that the dumbbell-shaped test piece 50 is constrained by the constraint device 30, and the triangular prism 23 in the clamp 20 is embedded between the constraint devices 30. The incident rod 10 transfers the horizontal loading force to the triangular prism 23 through the clamp 20, and vertically transfers the loading force to the constraint device 30 through the triangular prism 23, so that dynamic stretching is performed between the steel bar 51 and the concrete 52 in the test piece 50, thereby testing the dynamic mechanical properties of the bonding interface between the two.

[0080] It can be seen from the dynamic mechanical testing device for the reinforced concrete bonding interface mentioned in the above embodiment that the testing device horizontally supports the reinforced concrete test piece through the clamp in the testing device, and stretches the test piece through the triangular prism in the clamp under the action of the horizontal loading force applied by the incident rod, thereby obtaining the dynamic mechanical test results of the bonding interface between the steel bar and concrete in the test piece; this scheme uses the Saint-Venant principle to design the size of the test piece and the clamp, decoupling the structural response of the test piece and the interface material response, and solves the problem of coupling between the interface test results and the structural response of the test piece in the existing reinforced concrete interface bonding strength test, making the reinforced concrete interface bonding strength test more accurate.

[0081] The embodiment of the present invention provides a dynamic mechanical testing method for the bond interface of reinforced concrete, which is applied to the dynamic mechanical testing device for the bond interface of reinforced concrete mentioned in the above embodiment, such as Figure 6 As shown, the method includes:

[0082] Step S601 : Fix the workpiece to be tested in a restraining device, and place the triangular prism of the fixture between the restraining devices.

[0083] First, a test piece consisting of steel bars and concrete is fabricated. Two identical concrete cylinders are cast at either end of the steel bar, centered around the steel bar's axis. The steel bar is embedded in the concrete cylinder on one side. After the concrete solidifies and cures, a bonded interface forms between the embedded steel bar and the concrete. Once the test piece is fabricated, it is secured in place with a fixture, with the triangular prism positioned between the restraining devices.

[0084] Step S602 : Control the incident rod to apply a loading force to the fixture, and obtain a mechanical characteristic curve between the restraint device and the workpiece in real time.

[0085] The incident rod transfers the loading force to the triangular prism through the fixture, and then transfers the loading force to the constraint device through the triangular prism, so that dynamic stretching occurs between the steel bars and the concrete in the test piece, thereby obtaining the mechanical characteristic curve between the constraint device and the test piece.

[0086] Step S603: determining the dynamic mechanical test result of the bonding interface between the steel bar and the concrete in the test piece according to the mechanical characteristic curve.

[0087] After the mechanical characteristic curve is obtained, the dynamic mechanical test results of the bonding interface between the steel bar and concrete in the test piece can be obtained based on the curve.

[0088] In one embodiment, the step S602 of controlling the incident rod to apply a loading force to the fixture and obtaining a mechanical characteristic curve between the restraint device and the workpiece in real time is as follows: Figure 7 Shown, including:

[0089] Step S701 : Using the strain gauge pre-attached to the incident rod, the strain data of the Hopkinson bar is acquired in real time, and the loading force is determined according to the strain data.

[0090] The dynamic test strain data ε(t) is collected by attaching a strain gauge to the incident rod of the Hopkinson bar. Assuming that the cross-sectional area of ​​the Hopkinson bar is A and the elastic modulus is E, the force exerted by the incident rod on the specimen is:

[0091] F = σA = EAε(t);

[0092] Where σ is the cross-sectional stress of the incident rod; F is the loading force.

[0093] Step S702 : After controlling the incident rod to apply a loading force to the fixture, a first acting force between the triangular prism and the incident rod is obtained in real time.

[0094] like Figure 9 As shown, the directions of the first forces F1 and F2 are perpendicular to the sides of the triangular prism. When the triangular cross-section of the triangular prism is an isosceles triangle, F1 and F2 are equal. In this case, β is the vertex angle of the triangular parallel faces of the triangular prism; α is the angle between F1 and F2 and the vertical direction. Based on the angle relationship, β = 2α.

[0095] From the analysis of horizontal and vertical forces, we can know that:

[0096] F1sin(α)+F2sin(α)=F

[0097] F1cos(α)=F2cos(α)

[0098] The force on the restraint device is,

[0099] Step S703: Determine a second force between the holding device and the restraining device using the first force.

[0100] like Figure 10 As shown, the triangular prism applies the first force to the restraint device, and according to the angle relationship, the second force

[0101] Step S704 : generating a mechanical characteristic curve between the restraint device and the workpiece to be tested according to the second force.

[0102] Figure 11 As shown, since the forces between the test piece and the restraint device are mutually vertical interaction forces, in one embodiment, step S603 of determining the dynamic mechanical test results of the bonding interface between the steel bar and the concrete in the test piece according to the mechanical characteristic curve is as follows: Figure 8 Shown, including:

[0103] Step S801, obtaining strain data in the mechanical characteristic curve;

[0104] Step S802: Calculate the force at the bonding interface between the steel bar and concrete in the test piece using the strain data. The force at the bonding interface between the steel bar and concrete is calculated using the following formula:

[0105]

[0106] Among them, F te (t) is the force between the bond interface of steel bar and concrete that changes with time t; ε(t) is the strain data of the incident rod that changes with time t; A is the cross-sectional area of ​​the incident rod; E is the elastic modulus; β is the vertex angle of the triangle in the parallel plane of the triangular prism;

[0107] Step S803: determining a dynamic mechanical test result based on the force acting on the bonding interface between the steel bar and the concrete.

[0108] It can be seen from the dynamic mechanical testing method of the reinforced concrete bonding interface mentioned in the above embodiment that this testing method horizontally supports the reinforced concrete test piece to be tested by the fixture in the testing device, and stretches the test piece through the triangular prism in the fixture under the action of the horizontal loading force applied by the incident rod, thereby obtaining the dynamic mechanical test results of the bonding interface between the steel bar and concrete in the test piece; this scheme uses the Saint-Venant principle to design the dimensions of the test piece and the fixture, decoupling the structural response of the test piece and the interface material response, and solving the problem of coupling between the interface test results and the structural response of the test piece in the existing reinforced concrete interface bonding strength test, so that the reinforced concrete interface bonding strength test has higher accuracy.

[0109] The dynamic mechanical testing device for the reinforced concrete bond interface in this method embodiment shares the same technical features as the dynamic mechanical testing device for the reinforced concrete bond interface provided in the aforementioned embodiment, thus solving the same technical problems and achieving the same technical effects. For the sake of brevity, any details not mentioned in the embodiment section are referenced to the corresponding content in the aforementioned embodiment.

[0110] This embodiment also provides an electronic device. The structural diagram of the electronic device is as follows: Figure 12 As shown, the device includes a processor 101 and a memory 102; wherein the memory 102 is used to store one or more computer instructions, and the one or more computer instructions are executed by the processor to implement the above-mentioned dynamic mechanical testing method of the reinforced concrete bonding interface.

[0111] Figure 12The electronic device shown further includes a bus 103 and a communication interface 104 , and the processor 101 , the communication interface 104 and the memory 102 are connected via the bus 103 .

[0112] The memory 102 may include a high-speed random access memory (RAM), and may also include a non-volatile memory, such as at least one disk storage. The bus 103 may be an ISA bus, a PCI bus, or an EISA bus. The bus may be divided into an address bus, a data bus, a control bus, etc. For ease of representation, Figure 12 Only one bidirectional arrow is used in the diagram, but this does not mean that there is only one bus or one type of bus.

[0113] The communication interface 104 is used to connect to at least one user terminal and other network units through a network interface, and send the encapsulated IPv4 message or IPv4 message to the user terminal through the network interface.

[0114] The processor 101 may be an integrated circuit chip with signal processing capabilities. During implementation, each step of the above method can be completed by an integrated logic circuit of hardware in the processor 101 or by instructions in the form of software. The above-mentioned processor 101 may be a general-purpose processor, including a central processing unit (CPU), a network processor (NP), etc.; it may also be a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or other programmable logic devices, discrete gates or transistor logic devices, discrete hardware components. The various methods, steps, and logic block diagrams disclosed in the embodiments of the present disclosure can be implemented or executed. The general-purpose processor may be a microprocessor or the processor may be any conventional processor, etc. The steps of the method disclosed in conjunction with the embodiments of the present disclosure can be directly embodied as being executed by a hardware decoding processor, or executed by a combination of hardware and software modules in the decoding processor. The software module can be located in a storage medium well-known in the art, such as random access memory, flash memory, read-only memory, programmable read-only memory, electrically erasable programmable memory, registers, etc. The storage medium is located in memory 102, and processor 101 reads information in memory 102 and, in conjunction with its hardware, completes the steps of the method of the aforementioned embodiment.

[0115] An embodiment of the present invention further provides a readable storage medium having a computer program stored thereon. When the computer program is executed by a processor, the steps of the dynamic mechanical testing method of the reinforced concrete bonding interface of the aforementioned embodiment are executed.

[0116] In the several embodiments provided in this application, it should be understood that the disclosed systems, devices and methods can be implemented in other ways. The device embodiments described above are merely schematic. For example, the division of the units is only a logical function division. There may be other division methods in actual implementation. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some communication interface, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0117] The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple network units. Some or all of these units may be selected to achieve the purpose of this embodiment according to actual needs.

[0118] In addition, each functional unit in each embodiment of the present invention may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit.

[0119] If the functions are implemented in the form of software functional units and sold or used as independent products, they can be stored in a non-volatile computer-readable storage medium that is executable by a processor. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art, or the part of the technical solution, can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes several instructions for enabling a computer device (which can be a personal computer, server, or network device, etc.) to execute all or part of the steps of the method described in each embodiment of the present invention. The aforementioned storage medium includes various media that can store program codes, such as a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk, or an optical disk.

[0120] Finally, it should be noted that the above-described embodiments are only specific implementation methods of the present invention, which are used to illustrate the technical solutions of the present invention, rather than to limit them. The scope of protection of the present invention is not limited thereto. Although the present invention has been described in detail with reference to the above-described embodiments, those skilled in the art should understand that any person skilled in the art can modify or easily conceive of changes to the technical solutions described in the above-described embodiments within the technical scope disclosed by the present invention, or replace some of the technical features therein with equivalents. Such modifications, changes, or replacements do not deviate from the spirit and scope of the technical solutions of the embodiments of the present invention, and should be included in the scope of protection of the present invention. Therefore, the scope of protection of the present invention shall be subject to the scope of protection of the claims.

Claims

1. A dynamic mechanical testing device for reinforced concrete bonding interface, characterized in that: The device comprises: an incident rod, a clamp, a restraining device, and a transmission rod; a test piece consisting of steel bars and concrete is arranged in the restraining device; the steel bars in the test piece pass through and are fixed in the concrete; The incident rod and the transmission rod are symmetrically arranged Hopkinson rods, the incident rod is used to apply a loading force, and the transmission rod is used to bear the loading force; The clamp comprises two symmetrical holding devices, each comprising a sleeve and a triangular prism; wherein the first joint portion of the sleeve contacts the incident rod and the transmission rod respectively; the second joint portion of the sleeve contacts the quadrilateral bottom surface of the triangular prism; the two triangular parallel faces of the triangular prism are parallel to the axial direction of the steel bar; and the two quadrilateral side faces of the triangular prism both contact the restraining device; The restraining device comprises two symmetrical restraining parts, each of which is provided with a restraining hole; the steel bar in the test piece passes through the restraining hole; The restraining component in the restraining device includes a protruding portion and a fixing portion; the fixing portion is a rectangular parallelepiped steel plate, the restraining hole is arranged at the symmetry axis of the fixing portion, and the diameter of the restraining hole is larger than the diameter of the steel bar; The protrusions are arranged on both sides of the fixing portion, and the protrusions are connected to two quadrilateral side surfaces of the triangular prism.

2. The dynamic mechanical testing device for reinforced concrete bonding interface according to claim 1, characterized in that: The test piece includes: a first concrete piece, a second concrete piece and the steel bar; the first concrete piece and the second concrete piece are identical hollow cylindrical concrete pieces; The first concrete member and the second concrete member are respectively arranged at both ends of the steel bar.

3. The dynamic mechanical testing device for reinforced concrete bonding interface according to claim 2, characterized in that: The diameter of the steel bar is 6 mm and the length is 110 mm; The first concrete member and the second concrete member have a height of 50 mm, an outer diameter of 66 mm, and an inner diameter of 6 mm; The steel bars are fixed at the cylindrical axis of the first concrete member and the second concrete member respectively; the steel bars pass through the top surfaces of the first concrete member and the second concrete member respectively; the two ends of the steel bars are located 20 mm away from the bottom surfaces of the first concrete member and the second concrete member respectively.

4. The dynamic mechanical testing device for reinforced concrete bonding interface according to claim 1, characterized in that: The sleeve in the holding device is a cylindrical sleeve; The inner bottom surface of the cylindrical sleeve is the first coupling portion of the sleeve; The outer bottom surface of the cylindrical sleeve is the second coupling portion of the sleeve; The area of ​​the second connecting portion is larger than the area of ​​the quadrilateral bottom surface of the triangular prism.

5. The dynamic mechanical testing device for reinforced concrete bonding interface according to claim 4, characterized in that: The triangular face of the triangular prism in the holding device is an isosceles triangle; the height of the isosceles triangle is not less than 60 mm; and the vertex angle of the triangular prism is 45-60 degrees.

6. The dynamic mechanical testing device for reinforced concrete bonding interface according to claim 5, characterized in that: The interval between the protrusions of the two symmetrical restraining parts is 20 mm; A chamfered area is provided in the protrusion, and the chamfered area is connected to the two quadrilateral side surfaces of the triangular prism.

7. A dynamic mechanical testing method for reinforced concrete bonding interface, characterized in that: The method uses the dynamic mechanical testing device for the reinforced concrete bonding interface according to any one of claims 1 to 6, and the method comprises: Fixing the workpiece to be tested in the restraining device, and placing the triangular prism of the fixture between the restraining devices; Controlling the incident rod to apply a loading force to the fixture, and obtaining a mechanical characteristic curve between the restraint device and the workpiece in real time; The dynamic mechanical test result of the bonding interface between the steel bar and the concrete in the test piece is determined according to the mechanical characteristic curve.

8. The dynamic mechanical testing method for reinforced concrete bonding interface according to claim 7, characterized in that: The step of controlling the incident rod to apply a loading force to the fixture and obtaining a mechanical characteristic curve between the restraint device and the workpiece in real time includes: Using a strain gauge pre-attached to the incident rod to obtain strain data of the Hopkinson bar in real time, and determining the loading force based on the strain data; After controlling the incident rod to apply the loading force to the fixture, a first acting force between the triangular prism and the incident rod is obtained in real time; Determining a second force between the holding device and the restraining device using the first force; A mechanical characteristic curve between the restraining device and the workpiece to be tested is generated according to the second acting force.

9. The dynamic mechanical testing method for reinforced concrete bonding interface according to claim 7, characterized in that: The step of determining the dynamic mechanical test result of the bonding interface between the steel bar and the concrete in the test piece according to the mechanical characteristic curve includes: Obtaining strain data from the mechanical characteristic curve; The strain data is used to calculate the force between the bonding interface of the steel bar and the concrete in the test piece; wherein the force between the bonding interface of the steel bar and the concrete is calculated by the following formula: ； in, The bond interface between the steel bar and the concrete changes with time the forces of change; for the incident rod over time Changing strain data; is the cross-sectional area of ​​the incident rod; is the elastic modulus; is the vertex angle of the triangle in the triangular parallel plane of the triangular prism; The dynamic mechanical test result is determined according to the acting force between the bonding interface of the steel bar and the concrete.

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