A large-tonnage small shear-span ratio beam test loading device and test method

Abstract

The application relates to a large-tonnage small-shear-span-ratio beam test loading device and a test method. The loading device comprises an H-shaped beam, a foundation, a support beam, a counterweight seat, a first connecting rod, a second connecting rod, a jack and a force measuring device. Two foundations are arranged to support two ends of an experimental component. A support beam is arranged on one of the foundations and is located below the experimental component. The counterweight seat is located below the experimental component. The H-shaped beam is located above the experimental component. The H-shaped beam is connected with the support beam through the first connecting rod. The H-shaped beam is connected with the counterweight seat through the second connecting rod. The jack is arranged between the H-shaped beam and the experimental component and is used for loading the loading point position of the experimental component. The force measuring device is used for testing the force at the first connecting rod and the second connecting rod. The application realizes a semi-self-balancing loading system, reduces the material consumption and breaks through the space limitation.

Description

Technical Field

[0001] This invention relates to a civil engineering testing device and method, and more particularly to a loading device and method for testing large-tonnage beams with small shear span ratios. Background Technology

[0002] Currently, the loading of test beams all adopts a direct counterweight loading scheme, which requires either self-balancing or external counterweights. However, for large-tonnage, small-span-ratio tests, self-balancing is difficult to achieve, requiring a large steel structure and wasting materials. External counterweight schemes require placing numerous counterweight blocks or driving piles at the supports; if these requirements cannot be met, the scheme cannot be implemented. Furthermore, this method requires a larger operating space. Therefore, there is a need to develop a scheme with less counterweight and a larger loading tonnage to meet the relevant test requirements.

[0003] Chinese patent CN109060555A discloses a four-point loading test scheme that can directly apply counterweights to beams. However, for large-tonnage beams with loading points located near supports, the counterweight scheme is difficult to implement, and excessively large loads can easily cause safety issues and low work efficiency. Furthermore, the four-point loading test scheme requires too much operating space, making it unsuitable for some specific application scenarios.

[0004] Chinese patent CN110274817A discloses a loading scheme based on the lever principle, which can expand the load by using a small counterweight to achieve a large loading force. However, it requires fixing the beam ends, which is difficult to achieve for large-tonnage beams. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of the existing technology and provide a test loading device and test method for large-tonnage beams with small shear span ratio.

[0006] The objective of this invention can be achieved through the following technical solutions:

[0007] This invention provides a loading device for a large-tonnage, small-span ratio beam test, used to perform loading tests on experimental components. The loading device includes an H-beam, a foundation, a support beam, a counterweight, a first connecting rod, a second connecting rod, a jack, and a force measuring device. Two foundations are provided to support both ends of the experimental component. The support beam is located on one of the foundations and is positioned below the experimental component. The counterweight is also located below the experimental component, and the H-beam is located above the experimental component. The H-beam and the support beam are connected by the first connecting rod, and the H-beam and the counterweight are connected by the second connecting rod. The jack is placed between the H-beam and the experimental component to apply load to the loading point of the experimental component. The force measuring device is located at the position where the H-beam connects the first and second connecting rods to measure the magnitude of the force at the first and second connecting rods.

[0008] In one embodiment of the present invention, an elastic support is further provided between the jack and the experimental component. The elastic support is used to prevent stress concentration and to release the rotation caused by the deflection of the experimental component during loading.

[0009] In one embodiment of the present invention, the elastic support adopts a structure or material with deformability.

[0010] In one embodiment of the present invention, a force sensor is installed below the jack. The loading device of the present invention applies force through a hydraulically detachable jack, controlled by an oil pump, the model of which can be selected according to the maximum load required for the test.

[0011] In one embodiment of the present invention, the H-beam has rigidity, holes are arranged on the H-beam, the H-beam is connected to the first connecting rod or the second connecting rod by an anchor, and the force measuring device is disposed at the anchor.

[0012] In one embodiment of the present invention, the H-shaped beam is a steel beam.

[0013] In one embodiment of the present invention, the first connecting rod or the second connecting rod is made of metal or non-metal material.

[0014] In one embodiment of the invention, a counterweight block is provided on the counterweight base. Other forms of counterweight can also be used, such as piling.

[0015] In addition, in this invention, the support beam can be arranged either inside the foundation or above the foundation, as long as it is located below the experimental component.

[0016] This invention further provides a test method for a large-tonnage, small-shear-span ratio beam test loading device, based on the aforementioned large-tonnage, small-shear-span ratio beam test loading device, comprising the following steps:

[0017] Step S1: Prepare the experimental components, foundation, support beams, and counterweights;

[0018] Step S2: Place the experimental component, place an elastic support at the loading point, place a jack on the elastic support, install the H-beam and fix it with a temporary device, and install the first connecting rod and the second connecting rod;

[0019] Step S3: Apply appropriate force to the jack, test the force on the force measuring device, and adjust the anchoring positions of the first connecting rod and the second connecting rod so that the measured force is distributed according to the length ratio of L1 and L2, where L1 is the distance between the first connecting rod and the jack, and L2 is the distance between the second connecting rod and the jack.

[0020] Step S4: Formal experiment, apply load using a jack, and apply load in stages according to force control until the experimental component fails.

[0021] In one embodiment of the present invention, the jack applies hydraulic pressure to generate a force of magnitude F. It can be obtained that the beam bears a concentrated force of approximately F. The force in the first connecting rod is L2 / (L1+L2)*F, and the force in the second connecting rod is L1 / (L1+L2)*F. By configuring L1 / (L1+L2)*F with a counterweight, the forces in the first and second connecting rods are balanced with the loading force applied to the beam by the jack.

[0022] In one embodiment of the present invention, the size of the experimental device is determined. In order to ensure that the H-beam remains horizontal during loading, the stiffness of the H-beam must be large enough. If the stiffness does not meet the requirements, the stiffness needs to be calculated so that the sum of the vertical deflection on the left side of the H-beam and the deformation of the first connecting rod and the sum of the vertical deflection on the right side of the H-beam and the deformation of the second connecting rod are controlled within a certain error range.

[0023] The loading device for large-tonnage, small-span ratio beam tests provided by this invention mainly consists of a loading mechanism, a force transmission mechanism, a support mechanism, and a counterweight mechanism. In this invention, the force from the jack is transmitted to the H-beam. One end of the H-beam is connected to the support beam via a first connecting rod, and the other end is connected to the counterweight via a second connecting rod. The ends of the first and second connecting rods are anchored using anchors or bolts, and a force measuring device is placed at the anchoring position. The support beam can be cast into the foundation or placed directly on the bottom of the experimental component.

[0024] This invention applies force using a jack and distributes that force via an H-beam. The force in the first connecting rod on the left balances the loading force applied to the experimental component by the jack, while the force in the second connecting rod on the right balances the force provided by the counterweight structure. The device provided by this invention is suitable for situations where large-tonnage loading is achieved but the counterweight cannot meet the required specifications due to various limitations. That is, a large loading force can be achieved using less counterweight, saving materials and overcoming existing tonnage limitations. This invention achieves a semi-self-balancing loading system, reducing material usage and overcoming space limitations associated with counterweights.

[0025] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0026] 1. Safe and reliable: Compared with traditional experimental schemes that require more counterweight, the scheme provided by this invention has a lower counterweight requirement, ensuring safety from excessive load.

[0027] 2. Economic: Compared with traditional experimental schemes, it occupies less space and requires fewer counterweight beams, thus reducing material and labor costs. Attached Figure Description

[0028] Figure 1 This is a three-dimensional structural schematic diagram of the loading device for the large-tonnage, small-span ratio beam test in Example 1;

[0029] Figure 2 This is a schematic diagram of the main structure of the loading device for the large-tonnage, small-span beam test in Example 1.

[0030] The numbers in the diagram are as follows:

[0031] 1. H-shaped beam,

[0032] 2. Force measuring device

[0033] 3. Jack,

[0034] 4. Flexible support,

[0035] 5. First connecting rod,

[0036] 6. Counterweight

[0037] 7. Support beam,

[0038] 8. Basics

[0039] 9. Experimental components

[0040] 10. Second connecting rod,

[0041] 11. Counterweight seat. Detailed Implementation

[0042] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0043] Example 1

[0044] refer to Figure 1 , Figure 2 This embodiment provides a loading device for a large-tonnage, small-span ratio beam test, used to perform a loading test on an experimental component 9. The loading device includes an H-beam 1, a foundation 8, a support beam 7, a counterweight 11, a first connecting rod 5, a second connecting rod 10, a jack 3, and a force measuring device 2. Two foundations 8 are provided to support both ends of the experimental component 9. The support beam 7 is provided on one of the foundations 8. The support beam 7 is located below the experimental component 9. The counterweight 11 is located below the experimental component 9. The H-beam 1 is located above the experimental component 9. The H-beam 1 and the support beam 7 are connected by the first connecting rod 5. The H-beam 1 and the counterweight 11 are connected by the second connecting rod 10. The jack 3 is placed between the H-beam 1 and the experimental component 9 to apply load to the loading point of the experimental component 9. The force measuring device 2 is located at the position where the H-beam 1 connects the first connecting rod 5 and the second connecting rod 10 to test the magnitude of the force at the first connecting rod 5 and the second connecting rod 10.

[0045] In this embodiment, an elastic support 4 is also provided between the jack 3 and the experimental component 9. The elastic support is used to prevent stress concentration and to release the rotation caused by the deflection of the experimental component 9 during the loading process.

[0046] In this embodiment, the elastic support 4 is a plate rubber support.

[0047] In this embodiment, a force sensor is installed below the jack 3. The loading device of the present invention applies force through a hydraulically detachable jack, controlled by an oil pump. The model of the jack can be selected according to the maximum load required for the test.

[0048] In this embodiment, the H-beam 1 has rigidity, holes are arranged on the H-beam 1, the H-beam 1 is connected to the first connecting rod 5 or the second connecting rod 10 by an anchor, and the force measuring device 2 is set at the anchor.

[0049] In this embodiment, the H-shaped beam 1 is a steel beam.

[0050] In this embodiment, the first connecting rod 5 or the second connecting rod 10 is made of precision rolled threaded steel.

[0051] In this embodiment, a counterweight block 6 is provided on the counterweight base 11.

[0052] In this embodiment, the support beam 7 is installed inside the foundation 8.

[0053] In this embodiment, a test method for a large-tonnage, small-shear-span ratio beam test loading device is further provided. Based on the aforementioned large-tonnage, small-shear-span ratio beam test loading device, the method includes the following steps:

[0054] Step S1: Prepare the experimental components 9, foundation 8, support beam 7, and counterweight 6;

[0055] Step S2: Place the experimental component 9, place the elastic support 4 at the loading point, place the jack 3 on the elastic support 4, install the H-beam 1 and fix it with a temporary device, and install the first connecting rod 5 and the second connecting rod 10.

[0056] Step S3: Apply appropriate force to jack 3, test the magnitude of the force on force measuring device 2, and adjust the anchoring positions of the first connecting rod 5 and the second connecting rod 10 so that the measured force is distributed according to the length ratio of L1 and L2, where L1 is the distance between the first connecting rod 5 and jack 3, and L2 is the distance between the second connecting rod 10 and jack 3.

[0057] Step S4: Formal experiment. Use jack 3 to apply load. The application process is carried out in stages according to force control until the experimental component 9 is destroyed.

[0058] In this embodiment, the hydraulic jack 3 applies hydraulic pressure to generate a force of magnitude F. It can be seen that the beam bears a concentrated force of approximately F. The force in the first connecting rod 5 is L2 / (L1+L2)*F, and the force in the second connecting rod 10 is L1 / (L1+L2)*F. By configuring L1 / (L1+L2)*F with a counterweight, the forces in the first connecting rod 5 and the second connecting rod 10 are balanced with the loading force applied to the beam by the hydraulic jack 3.

[0059] In this embodiment, the size of the experimental device is determined. In order to ensure that the H-beam 1 remains horizontal during loading, the stiffness of the H-beam 1 must be large enough. If the stiffness does not meet the requirements, the stiffness needs to be calculated so that the sum of the vertical deflection on the left side of the H-beam 1 and the deformation of the first connecting rod 5 and the sum of the vertical deflection on the right side of the H-beam 1 and the deformation of the second connecting rod 10 are controlled within a certain error range.

[0060] The loading device for the large-tonnage, small-span ratio beam test provided in this embodiment mainly consists of a loading mechanism, a force transmission mechanism, a support mechanism, and a counterweight mechanism. In this invention, the force of the jack is transmitted to the H-beam 1. One end of the H-beam 1 is connected to the support beam 7 via a first connecting rod 5, and the other end is connected to the counterweight block 6 via a second connecting rod 10. The ends of the first connecting rod 5 and the second connecting rod 10 are anchored by anchors or bolts, and a force measuring device 2 is placed at the anchoring position. The support beam 7 can be cast in the foundation 8 or placed directly on the bottom of the beam of the experimental component 9.

[0061] This invention applies force using a jack and distributes that force via an H-beam. The force in the first connecting rod on the left balances the loading force applied to the experimental component by the jack, while the force in the second connecting rod on the right balances the force provided by the counterweight structure. The device provided by this invention is suitable for situations where large-tonnage loading is achieved but the counterweight cannot meet the required specifications due to various limitations. That is, a large loading force can be achieved using less counterweight, saving materials and overcoming existing tonnage limitations. This invention achieves a semi-self-balancing loading system, reducing material usage and overcoming space limitations associated with counterweights.

[0062] 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 loading device for testing large-tonnage beams with small shear span ratios, characterized in that, The loading device is used to perform loading tests on the experimental component (9). The loading device includes an H-beam (1), a foundation (8), a support beam (7), a counterweight (11), a first connecting rod (5), a second connecting rod (10), a jack (3), and a force measuring device (2). Two foundations (8) are provided to support the two ends of the experimental component (9). The support beam (7) is provided on one of the foundations (8). The support beam (7) is located below the experimental component (9). The counterweight (11) is located below the experimental component (9). The H-beam (1) is located below the experimental component (9). Above the test component (9), the H-shaped beam (1) is connected to the support beam (7) by a first connecting rod (5), and the H-shaped beam (1) is connected to the counterweight seat (11) by a second connecting rod (10). The jack (3) is placed between the H-shaped beam (1) and the test component (9) to load the loading point of the test component (9). The force measuring device (2) is set at the position where the H-shaped beam (1) connects the first connecting rod (5) and the second connecting rod (10) to test the magnitude of the force at the first connecting rod (5) and the second connecting rod (10). An elastic support (4) is also provided between the jack (3) and the experimental component (9), and a force sensor is provided below the jack (3); holes are arranged on the H-beam (1), and the H-beam (1) is connected to the first connecting rod (5) or the second connecting rod (10) by an anchor, and the force measuring device (2) is set at the anchor. The counterweight base (11) is provided with a counterweight block (6); The elastic support (4) is made of a structure or material with deformation capacity, and the H-beam (1) is a steel beam.

2. The loading device for a large-tonnage beam with a small shear span ratio according to claim 1, characterized in that, The first connecting rod (5) or the second connecting rod (10) is made of metal or non-metal materials.

3. A test method for a loading device for a large-tonnage beam with a small shear span ratio, characterized in that, The test loading device for large-tonnage small-shear-span ratio beams according to any one of claims 1-2 is used, and includes the following steps: Step S1: Prepare the experimental components (9), foundation (8), support beam (7), and counterweight (6); Step S2: Place the experimental component (9), place the elastic support (4) at the loading point, place the jack (3) on the elastic support (4), install the H-beam (1) and fix it with a temporary device, and install the first connecting rod (5) and the second connecting rod (10). Step S3: Apply appropriate force to the jack (3), test the magnitude of the force on the force measuring device (2), and adjust the anchoring positions of the first connecting rod (5) and the second connecting rod (10) so that the measured force is distributed according to the length ratio of L1 and L2, where L1 is the distance between the first connecting rod (5) and the jack (3), and L2 is the distance between the second connecting rod (10) and the jack (3); Step S4: Formal experiment, use jack (3) to apply load, and apply load in stages according to force control until the experimental component (9) is destroyed; The jack (3) applies hydraulic pressure to generate a force of magnitude F. The force in the first connecting rod (5) is L2 / (L1+L2)*F, and the force in the second connecting rod (10) is L1 / (L1+L2)*F. By configuring L1 / (L1+L2)*F with the counterweight, the force in the first connecting rod (5) and the second connecting rod (10) is balanced with the loading force applied to the beam by the jack (3).

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