Compressed member loading device capable of finely adjusting eccentric direction and eccentric distance

Abstract

The invention relates to a compressed member loading device capable of finely adjusting an eccentric direction and an eccentric distance, comprising: an upper loading mechanism comprising an upper cutter reaming plate fixed on an actuator, an upper connecting plate, an upper cutter reaming piece, and an upper hooping assembly fixed on the lower surface of the upper connecting plate, the upper hooping assembly is used for fixing the top of a channel steel test piece, and the upper hooping assembly is used for fixing the top of the channel steel test piece; the eccentric state of the channel steel test piece around a strong axis or a weak axis can be adjusted; the lower loading mechanism comprises a lower cutter reaming plate fixed on the counter-force cross beam, a lower connecting plate positioned above the lower cutter reaming plate, a lower cutter reaming piece arranged between the lower cutter reaming plate and the lower connecting plate, and a lower hooping assembly fixed on the upper surface of the lower connecting plate, and the lower hooping assembly is used for fixing the top of a channel steel test piece; and the eccentric state of the channel steel test piece around a strong axis or a weak axis can be adjusted. Compared with the prior art, the device can meet the requirements of finely adjusting eccentricity around a weak axis or a strong axis and the eccentric distance in a channel steel eccentric compression test.

Description

Technical Field

[0001] This invention belongs to the field of eccentric compression component testing technology, and relates to a loading device for compression components with finely adjustable eccentricity direction and eccentricity distance. Background Technology

[0002] Cold-formed thin-walled channel steel is widely used in photovoltaic brackets, portal frames, and light steel structure workshops due to its lightweight and high strength. In order to meet the requirements of corrosion resistance or high strength, alloying elements need to be added to the steel itself. Therefore, it is very necessary to study the mechanical properties of these new types of steel.

[0003] When conducting eccentric compression tests on cold-formed thin-walled channel steel members, the specimen is typically welded to a specific location on an end plate before being mounted on a loading platform for loading. However, during the welding process, residual welding stress is generated due to localized heating and cooling. This stress may affect the specimen's compressive behavior, leading to inaccurate or non-repeatable test results. Furthermore, poor welding quality may result in insufficient strength at the connection, affecting the overall performance of the specimen and even causing localized failure at the connection. Welding fixation may also lead to eccentricity or misalignment of the specimen during installation. Finally, the requirement to weld end plates to each specimen before conducting the eccentric compression test increases the testing cost.

[0004] For example, Chinese patent CN117288578B provides a loading device for eccentrically compressed members with fine adjustment of eccentricity. It includes pads at both ends of a reinforced concrete column, an eccentricity calibration steel plate on the pads, a scissor plate, and a stiffening assembly on the scissor plate. The pads are fixedly connected to the longitudinal reinforcement bars in the reinforced concrete column. The pads have limiting screws for fixing the scissor plate. The eccentricity calibration steel plate has a slotted hole through which the limiting screws pass to fix the scissor plate. The stiffening assembly includes a loading end on the scissor plate and a loading plate on the loading end. The scissor plate has teeth to limit the sliding of the loading end when it forms an angle with the scissor plate during loading. The pads have a fixing assembly to limit the sliding of the scissor plate. However, this invention is only suitable for reinforced concrete columns and not for channel steel. Furthermore, it can only adjust the eccentricity in one direction, still failing to meet the fine adjustment requirements for channel steel specimens. Summary of the Invention

[0005] The purpose of this invention is to provide a precise and adjustable loading device for compression components with adjustable eccentricity direction and eccentricity distance. This device can effectively adjust the channel steel specimen to rotate around the weak axis or strong axis and the eccentricity distance, ensuring the accurate fixation of the load application position and solving problems such as unstable eccentric loading and high cost.

[0006] The objective of this invention can be achieved through the following technical solutions: A compression member loading device with fine adjustable eccentricity direction and eccentricity, comprising: An upper loading mechanism, including an upper knife绞板 (should be '绞板' replaced with '绞盘' perhaps, assume it as '绞盘' here) fixed on an actuator, an upper connecting plate located below the upper knife绞盘, an upper knife绞件 (should be '绞件' replaced with '绞合件' perhaps, assume it as '绞合件' here) provided between the upper knife绞盘 and the upper connecting plate, and an upper hoop assembly fixed on the lower surface of the upper connecting plate. The upper hoop assembly is used to fix the top of the channel steel specimen and can adjust the eccentric state of the channel steel specimen around the strong axis or the weak axis; A lower loading mechanism, including a lower knife绞盘 fixed on the reaction cross beam, a lower connecting plate located above the lower knife绞盘, a lower knife绞合件 provided between the lower knife绞盘 and the lower connecting plate, and a lower hoop assembly fixed on the upper surface of the lower connecting plate. The lower hoop assembly is used to fix the top of the channel steel specimen and can adjust the eccentric state of the channel steel specimen around the strong axis or the weak axis.

[0007] Furthermore, both the upper hoop assembly and the lower hoop assembly include a hoop base in the shape of a '回' character (should be '回' replaced with '回' is actually '口' character, assume it as '口' here), a slot unit for clamping and fixing the end of the channel steel specimen, and a hoop locking unit for adjusting and fixing the position of the slot unit on the hoop base. The middle area of the hoop base has a cavity in the shape of a '口' character, and the slot unit is located in the '口' - shaped cavity and its position is adjustable.

[0008] Even further, the slot unit includes a slot base, slot clamping blocks, and a slot locking rod. The slot base is provided with a strip - shaped slot into which the end of the channel steel specimen can be inserted. There are two slot clamping blocks, which are placed in the strip - shaped slot and can move within the strip - shaped slot. The slot locking rod can extend into the strip - shaped slot from outside the hoop base and抵住 (should be '抵住' replaced with 'abut against') the slot clamping blocks to clamp and fix the end of the channel steel specimen through the cooperation of the two slot clamping blocks and the strip - shaped slot.

[0009] More preferably, strip - shaped holes are processed on both sides of the hoop base for the slot locking rod to pass through; The hoop base is also provided with strip - shaped grooves parallel to the strip - shaped holes. The two ends of the slot base extend into the strip - shaped grooves and are restricted in their movement stroke by the strip - shaped grooves; The end of the slot clamping block is also provided with holes for the slot locking rod to match and extend into.

[0010] Even further, the hoop locking unit includes a hoop clamping block and a hoop locking rod. The hoop clamping block is placed in the '口' - shaped cavity and is located on both sides of the slot unit respectively. The hoop locking rod passes through the hoop base and抵住 (should be '抵住' replaced with 'abut against') the hoop clamping block to tightly lock the slot unit.

[0011] More preferably, there are at least two hoop locking rods on each side, and hoop through - holes for the hoop locking rods to pass through are processed on the side wall of the hoop base. It should be noted that there are some unclear or incorrect terms in the original Chinese text (such as '刀绞板', '刀绞件'), and the translation is adjusted as much as possible based on reasonable assumptions. If the original text can be further clarified, the translation will be more accurate.

[0012] Furthermore, the hoop base is installed on the upper or lower connecting plate by fixing bolts, and the installation direction of the hoop base on the upper or lower connecting plate is adjustable to selectively fix the transverse or longitudinal sides of the end of the channel steel specimen.

[0013] Furthermore, the upper surface of the upper connecting plate has an upper cutting edge that allows the upper cutting tool to be matched and entered, and the lower surface of the lower connecting plate has a lower cutting edge that allows the lower cutting tool to be matched and entered.

[0014] Furthermore, the upper blade plate and the upper connecting plate are provided with corresponding limiting through holes at their four corners. Before the load test, the distance between the upper connecting plate and the upper blade plate is fixed by limiting bolts that match the limiting through holes.

[0015] Furthermore, the upper blade plate and the upper connecting plate are also provided with corresponding safety bolts on both sides. During the loading test, after the limit bolts are removed, the safety bolts on each side are connected and fixed by safety steel cables.

[0016] In operation, this invention involves inserting both ends of the channel steel specimen into the slots of the upper and lower retaining ring bases. At this point, the channel steel specimen is in a preliminary, approximately centered position. The position of the retaining ring base is then adjusted using the retaining ring locking rod, and finally, the position of the channel steel specimen in another vertical direction is adjusted using the retaining ring locking rod to achieve eccentricity adjustment in both directions. If eccentricity around another axis is required, it can be achieved by changing the installation direction of the retaining ring base on the upper / lower connecting plates (rotating 90 degrees).

[0017] The compression member loading device provided by the present invention has significant improvements in the following aspects: 1. This invention employs a "separate design of the slot unit and the clamping unit." The slot unit is responsible for fixing and fine-tuning the position of the component in one direction, while the clamping unit is responsible for locking the position of the entire slot unit in another vertical direction. This functional separation makes the adjustment logic clear and the operations do not interfere with each other. It achieves "refined" eccentric adjustment. Each dimension can be adjusted and locked individually and precisely.

[0018] 2. This invention adopts a "rotatable hoop base installation method". Through simple reinstallation, it realizes the switching from "eccentricity around the weak axis" to "eccentricity around the strong axis" with the lowest cost and the highest efficiency, which greatly improves the versatility of the device and realizes "one machine for two purposes", thereby "saving costs".

[0019] 3. This invention employs a "non-welding mechanical clamping and fixing" method, using a mechanical method of clamping with slots and blocks and tightening with retaining ring blocks throughout the process, completely avoiding welding. This fundamentally eliminates the influence of welding residual stress on the mechanical properties of the specimen, while avoiding the strength weakening and misalignment problems caused by welding, significantly improving the accuracy and repeatability of the test.

[0020] Compared with the prior art, the present invention has the following advantages: (1) The present invention will not generate residual welding stress due to welding the ends of the channel steel specimen.

[0021] (2) The present invention can adjust the channel steel specimen to be around the weak axis or strong axis and the eccentric distance during the test, so as to ensure the accurate fixation of the load application position.

[0022] (3) The present invention can be applied to channel steel specimens with the same flange length to perform eccentric compression tests around the weak axis or strong axis at different eccentric distances, which can save costs. If it is necessary to test channel steel specimens with other cross sections, the dimensions of the slot and the hoop can be designed to meet the requirements. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the strong axial biasing structure of the grooved steel specimen of the present invention; Figure 2 This is a schematic diagram of the weak-axis biasing structure of the grooved steel specimen of the present invention; Figure 3 This is an exploded schematic diagram of a column bias loading device; Explanation of markings in the diagram: 1-Upper blade reamer; 101-Upper blade reamer; 2-Upper connecting plate; 21-Upper blade edge; 3-Limit bolt; 4-Safety cable; 5-Cage base; 501-Strip hole; 502-Strip groove; 503-Fixing bolt; 504-Cage through hole; 6-Slot base; 601-Slot through hole; 7-Slot locking rod; 701-Slot locking block; 8-Cage locking rod; 801-Cage locking block; 9-Lower connecting plate; 901-Lower blade edge; 10-Lower blade reamer; 1001-Lower blade reamer; 12-Channel steel specimen. Detailed Implementation

[0024] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments. These embodiments are based on the technical solution of the present invention and provide detailed implementation methods and specific operating procedures. However, the scope of protection of the present invention is not limited to the following embodiments.

[0025] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.

[0026] As used herein, the terms "and / or," "or / and," and "and / or" encompass any one of two or more of the related listed items, as well as any and all combinations of the related listed items. These arbitrary and all combinations include any two related listed items, any more related listed items, or a combination of all related listed items. It should be noted that when at least three items are connected using at least two conjunctions selected from "and / or," "or / and," and "and / or," it should be understood that, in this application, the technical solution undoubtedly includes solutions connected by "logical AND," and also undoubtedly includes solutions connected by "logical OR."

[0027] In this application, the technical features described in an open-ended manner include both closed technical solutions consisting of the listed features and open technical solutions that include the listed features.

[0028] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0029] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0030] Unless otherwise specified, all embodiments and optional embodiments of this application can be combined to form new technical solutions. Unless otherwise specified, all technical features and optional technical features of this application can be combined to form new technical solutions.

[0031] To effectively adjust the channel steel specimen 11 to rotate around the weak axis or strong axis and the eccentricity distance, ensure the accurate fixation of the load application position, and solve the problems of unstable eccentric loading and high costs, the present invention provides a compression member loading device with fine adjustable eccentric direction and eccentricity, as Figures 1 to 3 shown, including: An upper loading mechanism, including an upper knife绞板 1 fixed on the actuator, an upper connecting plate 2 located below the upper knife绞板 1, an upper knife绞件 101 provided between the upper knife绞板 1 and the upper connecting plate 2, and an upper hoop assembly fixed on the lower surface of the upper connecting plate 2. The upper hoop assembly is used to fix the top of the channel steel specimen 11 and can adjust the eccentric state of the channel steel specimen 11 around the strong axis or weak axis; A lower loading mechanism, including a lower knife绞板 10 fixed on the reaction cross beam, a lower connecting plate 9 located above the lower knife绞板 10, a lower knife绞件 1001 provided between the lower knife绞板 10 and the lower connecting plate 9, and a lower hoop assembly fixed on the upper surface of the lower connecting plate 9. The lower hoop assembly is used to fix the top of the channel steel specimen 11 and can adjust the eccentric state of the channel steel specimen 11 around the strong axis or weak axis.

[0032] In some specific embodiments, both the upper hoop assembly and the lower hoop assembly include a hoop base 5 in the shape of a "return" character, a slot unit for clamping and fixing the end of the channel steel specimen 11, and a hoop locking unit for adjusting and fixing the position of the slot unit on the hoop base 5. The middle area of the hoop base 5 has a square-shaped cavity, and the slot unit is located in the square-shaped cavity and its position is adjustable.

[0033] In a more specific embodiment, the slot unit includes a slot base 6, a slot clamping block 701, and a slot locking rod 7. The slot base 6 is provided with a strip-shaped slot into which the end of the channel steel specimen 11 can be inserted. There are two slot clamping blocks 701, which are placed in the strip-shaped slot and can move within the strip-shaped slot. The slot locking rod 7 can extend into the strip-shaped slot from outside the hoop base 5 and抵住 the slot clamping block 701 to clamp and fix the end of the channel steel specimen with the cooperation of the two slot clamping blocks 701 and the strip-shaped slot.

[0034] It should be noted that the term "绞板" in the original text may be a specific technical term in Chinese, and if there is a more accurate English equivalent, it can be further replaced for better understanding. Also, the text may contain some minor typos or unclear expressions in the original Chinese, which are translated as accurately as possible based on the context.In a more preferred embodiment, the two sides of the clamp base 5 are machined with strip-shaped holes 501 through which the locking rod 7 passes; the clamp base 5 is also provided with strip-shaped grooves 502 parallel to the strip-shaped holes 501, and the two ends of the slot base 6 extend into the strip-shaped grooves 502 and are restricted in their movement by the strip-shaped grooves 502; the end of the slot block 701 is also provided with a hole into which the locking rod 7 can be inserted. The strip-shaped grooves 502 can ensure that the slot base 6 can move freely within its range of motion to a certain extent. In addition, the slot base 6 is also provided with a slot through hole 601, which has an internal thread and is threadedly engaged with the locking rod 7. The locking rod 7 extends into the strip-shaped slot through the strip-shaped hole 501 and the slot through hole 601, and then inserts into the blind hole of the slot block 701, which can restrict the movement of the channel steel specimen 11 and thus adjust the eccentricity in this direction.

[0035] In a more specific embodiment, the hoop locking unit includes a hoop clamping block 801 and a hoop locking rod 8. The hoop clamping block 801 is placed in the U-shaped cavity and is located on both sides of the slot unit. The hoop locking rod 8 passes through the hoop base 5 and abuts against the hoop clamping block 801 to lock the slot unit.

[0036] More preferably, at least two of the clamp locking rods 8 are provided on each side, and the side wall of the clamp base 5 is machined with clamp through holes 504 through which the clamp locking rods 8 can pass. Specifically, the clamp through holes 504 are provided with internal threads, so that by engaging with the threads of the clamp locking rods 8, the position of the clamp block 801 can be effectively adjusted, thereby fixing the position of the slot unit and thus achieving the purpose of adjusting the eccentric distance in one direction. In addition, it should be noted that the extension and retraction adjustment direction of the clamp locking rods 8 is perpendicular to the adjustment direction of the slot locking rods 7 inside the slot unit, that is, one is horizontal and the other is vertical.

[0037] In a more specific embodiment, the hoop base 5 is installed on the upper connecting plate 2 or the lower connecting plate 9 by fixing bolts 503, and the installation direction of the hoop base 5 on the upper connecting plate 2 or the lower connecting plate 9 is adjustable to selectively fix the transverse sides or longitudinal sides of the end of the channel steel specimen 11.

[0038] In some specific embodiments, the upper surface of the upper connecting plate 2 has an upper cutting edge 21 that allows the upper cutting member 101 to be matched and entered, and the lower surface of the lower connecting plate 9 has a lower cutting edge 901 that allows the lower cutting member 1001 to be entered.

[0039] In some specific embodiments, position-corresponding limiting through holes are respectively provided at the four end corners of the upper knife plate 1 and the upper connecting plate 2. Before the loading test, the distance between the upper connecting plate 2 and the upper knife plate 1 is fixed by a limiting bolt 3 that matches the limiting through hole.

[0040] In a more specific embodiment, safety bolts are also provided at the corresponding positions on both sides of the upper knife plate 1 and the upper connecting plate 2. During the loading test, when the limiting bolt 3 is removed, the safety bolts on each side are connected and fixed by a safety steel cable 4.

[0041] Each of the above embodiments can be implemented independently, or can be combined in any pair or in more combinations.

[0042] The above embodiments will be described in more detail below in conjunction with specific examples.

[0043] Example 1: To effectively adjust the channel steel specimen 11 to be eccentric about the weak axis or the strong axis and the eccentricity distance, ensure the precise fixation of the load application position, and solve problems such as unstable eccentric loading and high costs, this example provides a compression member loading device with a finely adjustable eccentric direction and eccentricity, as Figures 1 to 3 shown, including: An upper loading mechanism, including an upper knife plate 1 fixed on an actuator, an upper connecting plate 2 located below the upper knife plate 1, an upper knife member 101 provided between the upper knife plate 1 and the upper connecting plate 2, and an upper hoop assembly fixed on the lower surface of the upper connecting plate 2. The upper hoop assembly is used to fix the top of the channel steel specimen 11 and can adjust the eccentric state of the channel steel specimen 11 about the strong axis or the weak axis; A lower loading mechanism, including a lower knife plate 10 fixed on a reaction cross beam, a lower connecting plate 9 located above the lower knife plate 10, a lower knife member 1001 provided between the lower knife plate 10 and the lower connecting plate 9, and a lower hoop assembly fixed on the upper surface of the lower connecting plate 9. The lower hoop assembly is used to fix the top of the channel steel specimen 11 and can adjust the eccentric state of the channel steel specimen 11 about the strong axis or the weak axis. )

[0044] Both the upper hoop assembly and the lower hoop assembly include a hoop base 5 in the shape of a "hui" character, a slot unit for clamping and fixing the end of the channel steel specimen 11, and a hoop locking unit for adjusting and fixing the position of the slot unit on the hoop base 5. The middle area of the hoop base 5 has a square-shaped cavity, and the slot unit is located in the square-shaped cavity and its position is adjustable.

[0045] The slot unit includes a slot base 6, a slot block 701, and a slot locking rod 7. The slot base 6 is provided with a strip-shaped slot that allows the end of the channel steel specimen 11 to be inserted. There are two slot blocks 701, which are placed in the strip-shaped slot and can move within the strip-shaped slot. The slot locking rod 7 can extend from the outside of the hoop base 5 into the strip-shaped slot and abut against the slot block 701, so that the end of the channel steel specimen 11 is clamped and fixed by the two slot blocks 701 cooperating with the strip-shaped slot.

[0046] The hoop base 5 has strip-shaped holes 501 on both sides for the slot locking rod 7 to pass through. The hoop base 5 also has strip-shaped grooves 502 parallel to the strip-shaped holes 501. Both ends of the slot base 6 extend into the strip-shaped grooves 502 and are restricted in their movement by the grooves. The end of the slot block 701 also has a hole for the slot locking rod 7 to be inserted. The strip-shaped grooves 502 ensure that the slot base 6 can move freely within its range of motion. Furthermore, the slot base 6 has a slot through hole 601 with internal threads that thread-fit the slot locking rod 7. The slot locking rod 7 extends through the strip-shaped holes 501 and 601 into the strip-shaped slot, and then into the blind hole of the slot block 701, thus restricting the movement of the channel steel specimen 11 and adjusting the eccentricity in this direction.

[0047] The hoop locking unit includes a hoop clamping block 801 and a hoop locking rod 8. The hoop clamping block 801 is placed in the U-shaped cavity and is located on both sides of the channel steel specimen 11. The hoop locking rod 8 passes through the hoop base 5 and abuts against the hoop clamping block 801 to lock the channel steel specimen 11.

[0048] At least two locking rods 8 are provided on each side, and the side wall of the hoop base 5 is machined with hoop through holes 504 through which the locking rods 8 can pass. Specifically, the hoop through holes 504 are internally threaded, so that by engaging with the threads of the locking rods 8, the position of the hoop block 801 can be effectively adjusted, thereby fixing the position of the slot unit and adjusting the eccentricity in one direction. In addition, it should be noted that the extension and retraction adjustment direction of the hoop locking rods 8 is perpendicular to the adjustment direction of the slot locking rods 7 inside the slot unit, that is, one is horizontal and the other is vertical.

[0049] The hoop base 5 is mounted on the upper connecting plate 2 or the lower connecting plate 9 by fixing bolts 503, and the mounting direction of the hoop base 5 on the upper connecting plate 2 or the lower connecting plate 9 is adjustable to selectively fix the transverse or longitudinal sides of the end of the channel steel specimen 11. See Figure 3The lower connecting plate 9 can be equipped with two sets of bolt holes corresponding to horizontal and vertical installation methods, respectively. These, along with the fixing bolts 503, allow for installation along either the horizontal or vertical sides. The upper connecting plate 2 is configured similarly.

[0050] The upper surface of the upper connecting plate 2 has an upper cutting edge 21 that allows the upper cutting member 101 to be matched and entered, and the lower surface of the lower connecting plate 9 has a lower cutting edge 901 that allows the lower cutting member 1001 to be entered.

[0051] The upper blade plate 1 and the upper connecting plate 2 are provided with corresponding limiting through holes at their four corners. Before the load test, the distance between the upper connecting plate 2 and the upper blade plate 1 is fixed by limiting bolts 3 that match the limiting through holes.

[0052] The upper blade plate 1 and the upper connecting plate 2 are also provided with corresponding safety bolts on both sides. During the loading test, after the limit bolts 3 are removed, the safety bolts on each side are connected and fixed by the safety steel cable 4.

[0053] The above description of the embodiments is provided to enable those skilled in the art to understand and use the invention. It will be apparent to those skilled in the art that various modifications can be made to these embodiments, and the general principles described herein can be applied to other embodiments without inventive effort. Therefore, the present invention is not limited to the above embodiments, and any improvements and modifications made by those skilled in the art based on the disclosure of the present invention without departing from the scope of the invention should be within the protection scope of the present invention.

Claims

1. A precise adjustable loading device for a compressed component, characterized in that, Comprising: An upper loading mechanism, including an upper knife绞板 (it seems there is a misspelling here, perhaps "绞板" should be "铰板" or something else, assuming it's "铰板" for translation) fixed on the actuator, an upper connecting plate located below the upper knife铰板, an upper knife member provided between the upper knife铰板 and the upper connecting plate, and an upper hoop assembly fixed on the lower surface of the upper connecting plate. The upper hoop assembly is used to fix the top of the channel steel specimen and can adjust the eccentric state of the channel steel specimen around the strong axis or the weak axis; A lower loading mechanism, including a lower knife铰板 fixed on the reaction cross beam, a lower connecting plate located above the lower knife铰板, a lower knife member provided between the lower knife铰板 and the lower connecting plate, and a lower hoop assembly fixed on the upper surface of the lower connecting plate. The lower hoop assembly is used to fix the top of the channel steel specimen and can adjust the eccentric state of the channel steel specimen around the strong axis or the weak axis.

2. The loading device for a compression member with finely adjustable eccentricity direction and eccentricity according to claim 1, characterized in that, Both the upper hoop assembly and the lower hoop assembly include a hoop base in the shape of a "回" character (assuming it should be "回" character, which might be a Chinese character for a specific shape), a slot unit for clamping and fixing the end of the channel steel specimen, and a hoop locking unit for adjusting and fixing the position of the slot unit on the hoop base. The middle area of the hoop base has a square-shaped cavity, and the slot unit is located in the square-shaped cavity and its position is adjustable.

3. The loading device for a compression member with finely adjustable eccentricity direction and eccentricity according to claim 2, characterized in that, The slot unit includes a slot base, slot clamping blocks, and a slot locking rod. The slot base is provided with a strip-shaped slot into which the end of the channel steel specimen can be inserted. There are two slot clamping blocks, which are placed in the strip-shaped slot and can move within the strip-shaped slot. The slot locking rod can extend into the strip-shaped slot from outside the hoop base and抵住 (assuming it means "抵住", which might be a misspelling, perhaps "抵住" should be "抵住" for a more accurate word, assuming it's "抵住" for translation) the slot clamping blocks, so as to clamp and fix the end of the channel steel specimen by the cooperation of the two slot clamping blocks and the strip-shaped slot.

4. The loading device for a compression member with finely adjustable eccentricity direction and eccentricity according to claim 3, characterized in that, Both sides of the hoop base are processed with strip-shaped holes through which the slot locking rod can pass; The hoop base is also provided with strip-shaped grooves parallel to the strip-shaped holes. The two ends of the slot base extend into the strip-shaped grooves and are restricted by the strip-shaped grooves in their moving stroke; The end of the slot clamping block is also provided with holes into which the slot locking rod can be inserted in a matching manner.

5. A loading device for a compression member with finely adjustable eccentricity direction and eccentricity according to claim 2, characterized in that, The hoop locking unit includes a hoop clamping block and a hoop locking rod. The hoop clamping block is placed in the square-shaped cavity and is located on both sides of the slot unit respectively. The hoop locking rod passes through the hoop base and抵住 (assuming it means "抵住", which might be a misspelling, perhaps "抵住" should be "抵住" for a more accurate word, assuming it's "抵住" for translation) the hoop clamping block to tightly lock the slot unit.

6. The loading device for a compression member with finely adjustable eccentricity direction and eccentricity according to claim 5, characterized in that, There are at least two hoop locking rods on each side of the hoop locking rod, and the side wall of the hoop base is processed with hoop through holes through which the hoop locking rod can pass.

7. A loading device for a compression member with finely adjustable eccentricity direction and eccentricity according to claim 2, characterized in that, The hoop base is installed on the upper connecting plate or the lower connecting plate through fixing bolts, and the installation direction of the hoop base on the upper connecting plate or the lower connecting plate is adjustable to selectively fix the horizontal or vertical sides of the end of the channel steel specimen.

8. The loading device for a compression member with finely adjustable eccentricity direction and eccentricity according to claim 1, characterized in that, The upper surface of the upper connecting plate has an upper knife edge into which the upper knife member can be inserted in a matching manner, and the lower surface of the lower connecting plate is provided with a lower knife edge for the lower knife member.

9. A loading device for a compression member with finely adjustable eccentricity direction and eccentricity according to claim 1, characterized in that, Limit through holes corresponding in position are respectively provided at the four end corners of the upper knife铰板 and the upper connecting plate. Before the loading test, the distance between the upper connecting plate and the upper knife铰板 is fixed by a limit bolt matching the limit through holes. It should be noted that there are some possible misspellings or unclear parts in the original text, which are translated as accurately as possible based on the understanding. If there are more specific requirements or corrections for the misspellings, the translation can be further adjusted.

10. A loading device for a compression member with finely adjustable eccentricity direction and eccentricity according to claim 9, characterized in that, The upper blade plate and the upper connecting plate are also provided with corresponding safety bolts on both sides. During the loading test, after the limit bolts are removed, the safety bolts on each side are connected and fixed by safety steel cables.

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