A building steel material tensile strength testing device and testing method

Abstract

This invention discloses a tensile strength testing device and method for structural steel. The key technical features are: two tensile seats with adjustable relative spacing; coaxial support cylinders on the two tensile seats; one end of the support cylinder is fixedly connected to the tensile seat, while the other end is suspended; a through hole is formed at the axial position of the support cylinder, and the inner circumference of both through holes is conical, gradually widening towards opposite sides; a clamping sleeve assembly for holding the steel strand is also included, comprising several evenly distributed annular fan-shaped members, each fan-shaped member forming a channel for the steel strand to pass through its inner circumference and a conical portion on its outer circumference to fit the through hole; the clamping sleeve assembly further includes a limiting component to maintain synchronous axial movement of each fan-shaped member within the through hole. This invention maintains the stability of the steel strand material in the clamping state, ensures stable circumferential stress on each individual wire, and improves the stability of the tensile test.

Description

Technical Field

[0001] This invention relates to the field of strength testing equipment technology, and more specifically, to a tensile strength testing device for building steel, and a testing method for the tensile strength of building steel. Background Technology

[0002] Steel strand is a common type of steel material, a steel product made of multiple steel wires twisted together. It serves to fix and reinforce buildings or columns, and during construction, it can also be used in conjunction with other concrete materials to stabilize and maintain the strength of building structures. During use, steel strand primarily bears tensile force; therefore, for rope-like materials like steel strand, its tensile strength is crucial and requires strength testing.

[0003] Currently, during the tensile strength testing of steel strands, two horizontally installed tension supports are used for support. One support is fixed, while the other can be adjusted relative to the horizontal direction to change the distance between them. Figure 2 The state of the steel strand. During the clamping process, it is usually fixed by a support cylinder and a split conical sleeve. The split conical sleeve consists of three fan-shaped rings that surround the steel strand axially, forming a conical sleeve structure on the outer periphery. The inner circumference of the support cylinder and the outer circumference of the conical sleeve are adapted to each other to form a wedge-shaped structure. When the conical sleeve is fitted into the support cylinder, it can press and clamp the outer periphery of the steel strand. Figure 1 As shown.

[0004] However, during the installation of each fan ring component, it is difficult to accurately adjust its axial and circumferential positions to ensure that the fan ring components are in a uniform state. This results in a certain clamping pressure difference between the fan ring components and the outer circumference of the steel strand. This will also cause a significant deviation in the pressure of the fan ring components on the inner circumference of the steel strand, and the pressure around each individual wire in the steel strand will also have a certain difference. This may lead to breakage at some locations with uneven stress, affecting the accuracy of the steel strand test.

[0005] Therefore, a new solution is needed to address this problem. Summary of the Invention

[0006] The purpose of this invention is to solve the above-mentioned problems by providing a tensile strength testing device for building steel, which can maintain the stability of steel strand material in the clamping state, maintain the stability of the force on each individual strand in the circumferential direction, and improve the stability of the tensile test.

[0007] The above-mentioned technical objective of the present invention is achieved through the following technical solution: a tensile strength testing device for building steel, comprising two tensile seats, the distance between the two tensile seats being adjustable relative to each other; a coaxial support cylinder is provided on the opposite side of each of the two tensile seats; one end of the support cylinder is fixedly connected to the tensile seat, the other end is suspended, a through hole is opened at the axial position of the support cylinder, the inner circumference of both through holes is conical and gradually widens towards the opposite side; it also includes a clamping sleeve assembly for clamping steel strands, the clamping sleeve assembly comprising a plurality of annularly evenly distributed fan-shaped rings, each fan-shaped ring forming a channel for the steel strand to pass through its inner circumference, and a conical portion for fitting the through hole on its outer circumference; the clamping sleeve assembly also includes a limiting component, the limiting component being used to maintain the synchronous axial movement of each fan-shaped ring within the through hole.

[0008] The present invention is further configured such that the limiting component includes a limiting ring one and a limiting ring two, the outer periphery of the fan ring member is formed with a limiting groove one that is adapted to the limiting ring one, the limiting grooves one are closed to form an annular structure, and the limiting ring is fitted inside each limiting groove one; the outer periphery of the fan ring member is formed with a limiting groove two that is adapted to the limiting ring two, the limiting grooves two are closed to form an annular structure, and the limiting ring two is fitted inside each limiting groove two.

[0009] The present invention is further configured such that the first limiting ring is fitted on the small diameter side of the conical part, and the second limiting ring is fitted on the large diameter side of the conical part; both the first limiting ring and the second limiting ring abut against the axial direction of the sector-shaped parts to keep the axial position of each sector-shaped part consistent.

[0010] The present invention is further configured such that a plurality of connecting strips are connected between the first limiting ring and the second limiting ring, the connecting strips are arranged in a circular array, and the two ends of the connecting strips are fixedly connected to the first limiting ring and the second limiting ring respectively, so as to apply a tensile force in a relative direction to the first limiting ring and the second limiting ring.

[0011] The present invention is further configured such that the opposite sides of the limiting ring one and the limiting ring two are respectively pressed against and positioned against the fan ring component.

[0012] The present invention is further configured such that a conical surface 1 and a conical surface 2 are formed on opposite sides of the limiting ring 1 and the limiting ring 2, respectively, and the opposite sides of the conical surface 1 and the conical surface 2 gradually shrink; a pressing surface 1 is formed on the inner side of the limiting groove 1 for pressing and limiting against the conical surface 1, and a pressing surface 2 is formed on the inner side of the limiting groove 2 for pressing and limiting against the conical surface 2.

[0013] The invention is further configured such that a connecting groove for accommodating a connecting strip is provided on the outer periphery of the fan ring; a guide recess is provided at the bottom of the middle section of the connecting groove; a guide protrusion is fixedly connected to the inner wall of the through hole; the guide protrusion and the guide recess are axially slidably adapted to each other; the guide protrusion and the connecting strip abut against each other and limit each other, for pressing the connecting strip into the guide recess and keeping the connecting strip taut; the connecting strip is a strip-shaped structure made of metal.

[0014] The present invention is further configured such that one end of the connecting strip is integrally connected to the limiting ring, the limiting ring has a slot for the connecting strip to pass through, and the outer circumference of the limiting ring is threaded with a bolt, which is pressed and fixed to the slot by the bolt; the slot has a curved structure.

[0015] The present invention is further configured such that the inner circumferential surfaces of the first limiting ring and the second limiting ring abut against the bottom surfaces of the first limiting groove and the second limiting groove, respectively.

[0016] The present invention also provides a test method for the tensile strength of building steel, which uses the test device described above to conduct the test. During the test, both ends of the steel are inserted into the through holes of the support cylinders on both sides and clamped and fixed by the clamping sleeve group; the two tension seats move in the axial direction to apply tension to both ends of the steel and conduct a tensile strength test.

[0017] In summary, the present invention has the following beneficial effects:

[0018] By using a support cylinder and a clamping sleeve assembly to clamp the steel strand during the clamping process, the clamping stability of the steel strand can be maintained. Furthermore, each sector ring in the clamping sleeve assembly is maintained by a limiting component, ensuring the circumferential stress stability of the steel strand during the tensile process and improving the stability of the test. The limiting component uses two circumferentially fitted limiting rings for limiting, and each ring can axially press against the sector ring, positioning it in both axial directions and maintaining the positional stability between the sector rings. This ensures that the pressure on each individual wire in the steel strand remains basically stable, improving the stability of the tensile test. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the steel strand clamping structure in the prior art;

[0020] Figure 2 This is a schematic diagram of the structure of a tensile strength testing device for building steel according to the present invention;

[0021] Figure 3 This is a schematic diagram of the structure of the support cylinder and clamping sleeve assembly of the present invention. Figure 1 ;

[0022] Figure 4 This is a schematic diagram of the structure of the support cylinder and clamping sleeve assembly of the present invention. Figure 2 ;

[0023] Figure 5 This is a schematic diagram of the clamping sleeve assembly of the present invention. Figure 1 ;

[0024] Figure 6 This is a schematic diagram of the clamping sleeve assembly of the present invention. Figure 2 ;

[0025] Figure 7 for Figure 5 Enlarged view of point A in the middle.

[0026] Reference numerals: 1. Steel strand; 2. Tensioning seat; 3. Support cylinder; 31. Through hole; 311. Guide protrusion; 4. Clamping sleeve; 40. Channel; 401. Gap; 41. Fan ring; 411. Conical part; 42. Limiting groove one; 421. Pressing surface one; 43. Limiting groove two; 431. Pressing surface two; 44. Limiting ring one; 441. Conical surface one; 45. Limiting ring two; 451. Conical surface two; 452. Slot; 453. Bolt; 46. Connecting strip; 47. Connecting groove; 471. Guide recess. Detailed Implementation

[0027] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0028] This embodiment discloses a tensile strength testing device for building steel. This device is mainly used to test the strength of steel strand 1. Figure 2 As shown, it includes two tension seats 2, one of which is in a fixed state, and the other tension seat 2 is slidably supported by a slide rail and driven by a driver, which can drive the two tension seats 2 to slide relative to each other and adjust the distance between the two tension seats 2, thus playing the role of sliding force during the tensioning process.

[0029] like Figure 1 , 2 As shown, each of the two tension seats 2 has a support cylinder 3 installed on its opposite side. One end of the support cylinder 3 is fixedly connected to the tension seat 2, and the other end extends in the opposite direction, appearing suspended. The two support cylinders 3 are coaxially arranged, and a through hole 31 is opened at the axis position. The inner circumference of both through holes 31 is conical, gradually widening towards the opposite side to form a trumpet-like structure.

[0030] A clamping sleeve 4 is installed at the through hole 31 inside the support cylinder 3. The clamping sleeve 4 is sleeved between the support cylinder 3 and the steel strand 1, and serves to clamp the steel strand 1.

[0031] like Figure 3-6 As shown, the clamping sleeve assembly 4 includes several evenly distributed annular fan-shaped members 41. The number of fan-shaped members 41 is generally three. Each fan-shaped member 41 encloses an axially distributed channel 40 on its inner circumference. The size of the channel is adapted to the steel strand 1, allowing the steel strand 1 to pass through for installation. Each fan-shaped member 41 can stably apply pressure to the steel strand 1 on its outer circumference, clamping and fixing the end of the steel strand 1. After the fan-shaped members 41 are closed, the resulting outer circumferential structure forms a tapered portion 411, which is adapted to the inner circumferential structure of the through hole 31. When the steel strand 1 is under tension, friction is generated between the steel strand 1 and the fan ring 41, causing the fan ring 41 to move towards the small diameter end of the through hole 31. At the same time, under the action of the tapered structure of the through hole 31, the fan ring 41 will generate a radial movement tendency, which will increase the clamping pressure of the fan ring 41 on the steel strand 1, thereby further stabilizing the clamping of the steel strand 1 and maintaining stable clamping of the steel strand 1, thus maintaining stability during the test.

[0032] Furthermore, since each fan ring 41 is in a relatively independent state, it is necessary to maintain the axial position of each fan ring 41 during installation. This requires adjustment based on the operator's experience, through tapping and swaying the fan ring 41 in different directions to maintain a relatively uniform installation state. When a certain error occurs during the installation of the fan ring 41, for example, if one fan ring 41 inserts deeper into the through hole 31 while the others insert less deeply, there will be differences in the pressure exerted on the steel strand 1 by the inner circumference of each fan ring 41. This will result in significant differences in the clamping pressure on each individual wire in the steel strand 1, leading to unstable fracture during tensile testing of the steel strand 1 and affecting the accuracy and stability of the tensile strength test.

[0033] In order to maintain the pressure of each sector member on the steel strand 1 in the clamping sleeve 4 basically the same, the clamping sleeve 4 also includes a limiting component. The limiting component is sleeved on the outer periphery of each sector ring member 41, which can maintain the synchronous axial movement of each sector ring member 41 inside the through hole 31, maintain the force stability of each sector ring member 41, and apply force to the outer periphery of the steel strand 1 evenly and stably.

[0034] like Figure 3-6 As shown, the limiting component includes a first limiting ring 44 and a second limiting ring 45. The two sets of annular limiting structures support and limit each fan ring 41, keeping the axial force of the fan ring 41 stable and maintaining a uniform positional relationship.

[0035] A limiting groove 42 adapted to a limiting ring 44 is formed on the outer periphery of the fan ring component 41. The limiting grooves 42 together form an annular structure, and the limiting ring 44 is fitted within each limiting groove 42. A limiting groove 43 adapted to a limiting ring 45 is formed on the outer periphery of the fan ring component 41. The limiting grooves 43 together form an annular structure, and the limiting ring 45 is fitted within each limiting groove 43. The limiting rings 44 and 45 respectively provide a limiting function within the two annular grooves of the annular structure. To maintain the stability of the limiting rings 44 and 45, during initial installation, the inner circumferential surfaces of the limiting rings 44 and 45 are kept in contact with the bottom surfaces of the limiting grooves 42 and 43, respectively. The relative stability of the position is maintained through the limiting between the circumferential surfaces. When the steel strand 1 is subjected to pressure, the outer diameter profile shrinks slightly. At this time, the inner circumference of the limiting ring separates from the fan ring 41. The end face of the limiting ring and the fan ring 41 press against each other to limit the movement. The stability between the fan rings 41 is maintained by the axial pressing and limiting action of the end face.

[0036] A first limiting ring 44 is fitted onto the small diameter side of the tapered portion 411, and a second limiting ring 45 is fitted onto the large diameter side of the tapered portion 411, forming two limiting points in the axial length direction to maintain the positional stability of the first limiting ring 44. Furthermore, both the first limiting ring 44 and the second limiting ring 45 abut against the axial direction of the sector components, forming an axial limiting effect and maintaining the axial positions of each sector component in a basically consistent state.

[0037] Several connecting strips 46 are connected between the first limiting ring 44 and the second limiting ring 45. Through the action of the connecting strips 46, an axial pulling force can be applied to the two limiting rings to bring them closer together, so that the first limiting ring 44 and the second limiting ring 45 can play an axial positioning role with the fan ring 41.

[0038] The two ends of the connecting strip 46 are fixedly connected to the first limiting ring 44 and the second limiting ring 45, respectively. It can be made of metal, such as steel, possessing a certain strength and elasticity. This force limits the initial position of each fan-ring component 41 within the support cylinder 3, ensuring that each fan-ring component 41 is evenly distributed from the initial tensioning state, thus maintaining the stability of the tension on the steel strand 1 during subsequent tensioning. The first limiting ring 44 and the second limiting ring 45 press against each other on opposite sides of the fan-ring component 41 for positioning. The fan-ring component 41 can simultaneously be subjected to bidirectional axial positioning forces, maintaining the position of each fan-ring component 41.

[0039] Furthermore, to improve the positional stability of the set of limiting ring 44 and limiting ring 45, an annular protrusion can be formed on the opposite side of limiting ring 44 and limiting ring 45, forming a hook-like structure at the inner peripheral edge. Specifically, as shown... Figure 4 ,5 As shown, conical surfaces 441 and 451 are formed on opposite sides of limiting ring 44 and limiting ring 45, respectively. The opposite sides of conical surfaces 441 and 451 gradually narrow and are inclined towards the sidewall of the corresponding limiting groove. Furthermore, a pressing surface 421 is formed inside limiting groove 42, and its structure is compatible with that of conical surface 441, allowing it to be fitted and adapted to the inner circumference of limiting ring 44. The structure of limiting groove 43 is similar, with a pressing surface 431 formed inside, which is compatible with conical surface 451.

[0040] When the limiting ring 44 and the limiting ring 45 are pressed together, the end faces of the corresponding limiting rings and the corresponding limiting grooves cooperate to press against each other. The pressing surface will press against the corresponding conical surface, forming a limiting effect in the inner circumferential direction. This can maintain the stability of the fitting between the limiting ring and the fan ring 41, maintain the axial positioning stability of the limiting ring 44 and the limiting ring 45, and keep each fan ring 41 in a uniform distribution state.

[0041] A connecting groove 47 is provided on the outer periphery of the fan ring 41. The number of connecting grooves 47 is the same as that of the connecting sleeve, and their sizes are matched. They are used to accommodate the connecting strips 46, so that the connecting strips 46 do not protrude from the outer periphery of the fan ring 41. Generally, there are three sets of connecting strips 46 and connecting grooves 47, corresponding to the outer periphery positions of three fan rings 41. The limiting ring 44, the limiting ring 45, and the multiple connecting strips 46 are interconnected to form a frame-like structure, which can limit the fan ring 41 to a basically stable range.

[0042] The aforementioned limiting components primarily serve to control the axial position of each fan ring 41, ensuring that the axial position of each fan ring 41 is uniform and stable. Additionally, a guide protrusion 311 can be fixedly connected to the inner wall of the through hole 31, the guide protrusion 311 being sized to match the connecting groove 47. During the insertion of the fan ring 41 into the through hole 31, the guide component 41 acts as a guide, maintaining axial movement only and ensuring circumferential stability, meaning the gap 401 between each fan ring 41 remains constant. During tension, each fan ring 41 maintains stable pressure on the steel strand 1, thereby improving the stability of the tensile test of the steel strand 1.

[0043] As the guide protrusion 311 slides into the connecting groove 47, it exerts pressure on the connecting sleeve within the connecting groove 47 in the direction of the inner circumference of the steel strand 1, thereby keeping the connecting bar 46 in a relatively taut state. The taut connecting bar 46 can apply pressure to the first limiting ring 44 and the second limiting ring 45, thereby causing the first limiting ring 44 and the second limiting ring 45 to move closer to each other, thus providing an axial limiting effect on the fan ring 41.

[0044] Furthermore, in order to increase the tensionable movement space of the connecting strip 46 within the connecting groove 47, a guide recess 471 can be provided at the bottom of the middle section of the connecting groove 47. A relatively smooth arc transition is formed between the guide recess 471 and the connecting groove 47. During the compression process, the connecting strip 46 can sink into the guide recess 471, thereby allowing the connecting strip 46 to be in a tensioned state. This enables the connecting strip 46 to apply a pulling force in the opposite direction to the limiting ring 44 and the limiting ring 45, with the limiting rings acting as axial limiters.

[0045] The shape and contour of the guide protrusion 311 can be adapted to the guide recess 471, so that when each fan ring 41 extends into the through hole 31, the guide protrusion 311 can also extend further into the guide recess 471 during the process of extending into the connecting groove 47. The arc-shaped protrusion of the guide protrusion 311 and the guide recess 471 are adapted to each other, playing a guiding and sliding role and limiting the rotation in the axial direction. In addition, the pressure of the guide protrusion 311 at the guide recess 471 can also form additional tension pressure on the connecting strip 46, keeping the force on the connecting strip 46 stable.

[0046] The connecting strip 46 can be a strip structure made of metal, such as an iron sheet. It is relatively thin and therefore has a certain degree of elasticity, which can achieve a certain range of swing. Under pressure, it can form a tension state, thereby playing a role in limiting the position of the first limiting ring 44 and the second limiting ring 45. Through the mutual pressing between each limiting ring and the fan ring 41, the position is maintained.

[0047] Furthermore, such as Figure 5 , 7 As shown, one end of the connecting strip 46 can be connected to the limiting ring 44, for example, by welding. The other end of the connecting strip 46 can be connected to the limiting ring 45 in an adjustable manner, either by locking it with bolts 453 or by loosening them to adjust the length of the connecting strip 46 between the limiting rings 44 and 45, allowing for adaptive adjustment. During adjustment, it is necessary to maintain that the lengths of each connecting strip 46 between the two limiting rings are basically consistent.

[0048] Regarding the specific connection structure between connecting strip 46 and limiting ring 45, as follows: Figure 7As shown, a slot 452 is provided inside the second limiting ring 45 for the connecting strip 46 to pass through. The slot 452 has a narrow and flat structure, which is adapted to the size of the connecting strip 46. The connecting strip 46 extends into the slot 452, passes through the slot 452, and extends out from the other end. A bolt 453 is threadedly connected to the outer circumference of the second limiting ring 45. The bolt 453 extends into the slot 452, and friction is generated by the bolt 453 pressing against the slot 452 to fix the position of the connecting sleeve and the second limiting ring 45. Loosening the bolt 453 allows the position of the connecting strip 46 to be adjusted.

[0049] Additionally, the slot 452 can be configured with a curved structure, and the bolt 453 can be pressed against the right side of the curved section, such as... Figure 7 The state shown is as follows. Through the pressing action of the bolt 453 and the connecting strip 46, the pressure formed by the bolt 453 on the connecting strip 46 in the slot 452 can be increased, thereby improving the fixing stability of the connecting strip 46.

[0050] This embodiment also discloses a test method for the tensile strength of building steel, which uses the test device in the above embodiment to test the strength of steel strand 1.

[0051] During the test, both ends of the steel are inserted into the through holes 31 of the support cylinders 3 on both sides and clamped and fixed by the clamping sleeve group 4. The two tension seats 2 move axially to apply tension to both ends of the steel to conduct a tensile strength test. One tension seat 2 is in a fixed state, while the other tension seat 2 is slidably supported by a slide rail and driven by a driver, which can adjust the relative sliding of the two tension seats 2 to increase the distance between them. During the stretching process, the applied tension is detected by a sensor until the steel strand 1 is normally broken, thereby obtaining the tensile strength information of the steel strand 1.

[0052] By using the support cylinder 3 and the clamping sleeve group 4 to clamp the steel strand 1 during the clamping process, the clamping stability of the steel strand 1 can be maintained. Furthermore, each sector ring 41 in the clamping sleeve group 4 is maintained by the limiting component, which can maintain the stress stability of each part of the steel strand 1 in the circumferential direction during the clamping and stretching process, thereby improving the stability of the test.

[0053] The above description is merely a preferred embodiment of the present invention. The scope of protection of the present invention is not limited to the above embodiments. All technical solutions falling within the scope of the present invention's concept are within the scope of protection of the present invention. It should be noted that for those skilled in the art, any improvements and modifications made without departing from the principle of the present invention should also be considered within the scope of protection of the present invention.

Claims

1. A tensile strength testing device for building steel, comprising two tensile seats (2), the distance between the two tensile seats (2) being adjustable relative to each other; a coaxial support cylinder (3) is provided on the opposite side of each of the two tensile seats (2); one end of the support cylinder (3) is fixedly connected to the tensile seat (2), and the other end is suspended; a through hole (31) is opened at the axial position of the support cylinder (3), and the inner circumference of both through holes (31) is conical, gradually widening towards the opposite side; characterized in that, It also includes a clamping sleeve assembly (4) for clamping the steel strand (1), the clamping sleeve assembly (4) including a plurality of annularly evenly distributed fan ring members (41), each fan ring member (41) forming a channel (40) for the steel strand (1) to pass through its inner circumference, and forming a tapered portion (411) on its outer circumference for fitting with the through hole (31); the clamping sleeve assembly (4) also includes a limiting component, the limiting component being used to maintain each fan ring member (41) moving synchronously axially inside the through hole (31); The limiting component includes a limiting ring one (44) and a limiting ring two (45). The outer periphery of the fan ring member (41) is formed with a limiting groove one (42) that is adapted to the limiting ring one (44). The limiting grooves one (42) together form an annular structure, and the limiting ring one (44) is sleeved in each limiting groove one (42). The outer periphery of the fan ring member (41) is formed with a limiting groove two (43) that is adapted to the limiting ring two (45). The limiting grooves two (43) together form an annular structure, and the limiting ring two (45) is sleeved in each limiting groove two (43). A plurality of connecting strips (46) are connected between the first limiting ring (44) and the second limiting ring (45). The connecting strips (46) are arranged in a ring array. The two ends of the connecting strips (46) are fixedly connected to the first limiting ring (44) and the second limiting ring (45) respectively, and can apply a tension force in the opposite direction to the first limiting ring (44) and the second limiting ring (45). The limiting ring one (44) and the limiting ring two (45) are respectively positioned by mutual pressing against the fan ring (41) on opposite sides; The limiting ring one (44) and the limiting ring two (45) have conical surfaces one (441) and two (451) respectively formed on opposite sides, and the opposite sides of the conical surfaces one (441) and two (451) gradually shrink; the limiting groove one (42) has a pressing surface one (421) formed on the inner side for pressing and limiting the conical surface one (441) against each other, and the limiting groove two (43) has a pressing surface two (431) formed on the inner side for pressing and limiting the conical surface two (451) against each other; The outer periphery of the fan ring (41) is provided with a connecting groove (47) for accommodating the connecting strip (46); a guide recess (471) is provided at the bottom of the middle section of the connecting groove (47); a guide protrusion (311) is fixedly connected to the inner wall of the through hole (31); the guide protrusion (311) and the guide recess (471) are axially slidably adapted to each other; the guide protrusion (311) and the connecting strip (46) press against each other and limit each other, which is used to press the connecting strip (46) into the guide recess (471) and keep the connecting strip (46) taut; the connecting strip (46) is a strip structure made of metal.

2. The tensile strength testing device for building steel according to claim 1, characterized in that, The first limiting ring (44) is sleeved on the small diameter side of the conical part (411), and the second limiting ring (45) is sleeved on the large diameter side of the conical part (411).

3. The tensile strength testing device for building steel according to claim 1, characterized in that, One end of the connecting strip (46) is integrally connected to the first limiting ring (44). The second limiting ring (45) has a slot (452) for the connecting strip (46) to pass through. The outer circumference of the second limiting ring (45) is threaded with a bolt (453), which is pressed and fixed to the connecting strip (46) by the bolt (453). The slot (452) has a curved structure.

4. The tensile strength testing device for building steel according to claim 2, characterized in that, The inner circumferential surfaces of the first limiting ring (44) and the second limiting ring (45) abut against the bottom surfaces of the first limiting groove (42) and the second limiting groove (43), respectively.

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