Reduced scale test method of truss structure node and test device thereof

Abstract

The invention relates to a reduced scale test method and device for truss structure nodes. The method comprises the steps that S1, a reduced scale node preliminary model is constructed according to original truss structure nodes and a reduced scale ratio; s2, verifying whether the reduced-scale node preliminary model has a problem after scale reduction or not, and if no problem exists or the reduced-scale node preliminary model is modified according to the problem after scale reduction, taking the reduced-scale node preliminary model or the modified reduced-scale node preliminary model as a reduced-scale node processing model; s3, placing the reduced scale node processing model on a loading reaction frame; and S4, selecting a compression type loading mode or a tension type loading mode to control the loading reaction frame, and applying pressure or pulling force to the reduced scale node processing model. By setting two loading modes, namely a compression type loading mode or a tension type loading mode, for respectively applying pressure or tension, compared with the traditional difficulty in applying the tension, the tension type loading mode is designed for applying the tension, so that the problem of difficulty in applying the tension is avoided.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of scale test of truss structure node, in particular to a scale test method of truss structure node and an experimental device thereof. BACKGROUND

[0002] In the research and engineering application of truss structure, as the key part connecting each member, the force performance of the node directly affects the safety and stability of the whole structure. In order to deeply understand the force behavior of the truss structure node, it is necessary to conduct relevant tests.

[0003] Due to the limitation of factors such as laboratory space, processing cost, transportation condition and loading equipment capacity, the original size node model cannot be tested, so scale test becomes a common means. However, there are many problems in the scale test process: 1. The scale steel structure member, such as longitudinal stiffening rib, may appear too dense and too thin, leading to difficult processing.

[0004] 2. The size of the closed section is too small, which makes the last steel plate unable to be welded internally, affecting the connection strength and stability of the member.

[0005] 3. The last weld of the transverse member such as the transverse plate is difficult to weld after closing the last steel plate, which brings inconvenience to construction.

[0006] 4. The existing reaction frame in the laboratory cannot realize the multi-point and multi-direction loading of the transfer member of the truss structure node, which cannot meet the test requirements.

[0007] 5. It is relatively easy to apply pressure to the member, but it is a difficult problem to effectively apply tension to the member, which restricts the comprehensiveness of the test.

[0008] The utility model patent with publication number CN218885623U discloses a scale test system for testing the strength of inclined column node, which is used for testing whether the strength of the connecting node of the inclined column and the stand column meets the standard. The lower end of the inclined column is fixed on the side surface of the stand column, and a support column beam is further arranged at the bottom of the side surface of the inclined column. The scale test system comprises a scale model of the connecting node of the inclined column and the stand column, and an actuator for simulating the load on the inclined column and the stand column. The scale model comprises a scale stand column, a scale inclined column and a scale support column beam, and the actuator comprises a straight actuator arranged at the top of the scale stand column and an inclined actuator arranged at the top of the scale inclined column. The patent solves the problem that the strength of the complex inclined column node is difficult to check by calculation or finite element simulation, but does not solve how to apply tension.

[0009] Therefore, how to effectively apply tension to the member is a problem that needs to be solved urgently at present. SUMMARY

[0010] The present application aims at providing a scaled test method for a truss structure node and an experimental device thereof to overcome the defects of the prior art.

[0011] The present application can be achieved by the following technical solutions. According to an aspect of the present application, a scaled test method for a truss structure node is provided, and the method comprises: S1, constructing a scaled node preliminary model according to an original truss structure node and a scaled ratio; S2, verifying whether the scaled node preliminary model has a scaled problem, and if not or modifying the scaled node preliminary model according to the scaled problem, taking the scaled node preliminary model or the modified scaled node preliminary model as a scaled node processing model; S3, placing the scaled node processing model on a loading counterforce frame; S4, selecting a compression type loading mode or a tension type loading mode to control the loading counterforce frame to apply pressure or tension to the scaled node processing model.

[0012] As a preferred technical solution, the scaled ratio is determined according to the processing feasibility, transportation convenience and loading capacity of the loading counterforce frame.

[0013] As a preferred technical solution, if the number of longitudinal stiffening ribs in the original truss structure node is large or a single longitudinal stiffening rib is thin, the longitudinal stiffening ribs are combined.

[0014] As a preferred technical solution, if the cross-sectional size of the scaled node preliminary model is small to cause the last steel plate to be unable to be internally welded, the cross-sectional size is widened and the fusion angle weld is performed outside the cross section.

[0015] As a preferred technical solution, if the number of transverse members of the scaled node preliminary model is large, the transverse members are combined.

[0016] As a preferred technical solution, if the transverse members of the scaled node preliminary model cannot be welded, the transverse members are replaced by plug welding or polished and tightly pressed according to the characteristics of being in tension or compression.

[0017] According to another aspect of the present invention, an experimental apparatus is provided for a scaled-down test method based on any of the truss structure nodes described above, comprising a fixed bracket, a compression bracket, a tension bracket, an eccentric bracket, and an actuator. The scaled-down node fabrication model includes a beam portion and a member portion having a fixed member, a compression member, an eccentric member, and a tension member. The loading reaction frame includes multiple support portions. The fixed bracket and the fixed member are connected and placed on the support portions. The compression bracket and the eccentric bracket are each connected to the compression member and the eccentric member respectively via actuators and placed on the support portions. The tension bracket is connected to the support portions via actuators. The tension member is placed on the tension bracket and the support portions. The compression bracket is connected to the beam portion via actuators and is disposed on the support portions.

[0018] As a preferred technical solution, the fixed rod, the compression rod, the eccentric rod, and the tension rod all include a sealing plate, and the sealing plates of the compression rod and the eccentric rod are connected to the actuator.

[0019] As a preferred technical solution, the device further includes a vertical plate, which is mounted on the support unit close to the eccentric bracket. The vertical plate, the pressure bracket, the actuator, and the crossbeam are connected in sequence.

[0020] As a preferred technical solution, the upright plate and the eccentric bracket are located on the same support.

[0021] Compared with the prior art, the present invention has attractive and beneficial effects: 1. This invention sets up two loading modes, namely compression loading mode or tension loading mode, to apply pressure or tension respectively. Compared with the difficulty of applying tension in the traditional method, the tension loading mode is designed to apply tension, thus avoiding the problem of difficulty in applying tension.

[0022] 2. After constructing the preliminary model of the scaled node, this invention needs to verify whether the preliminary model has problems such as ease of processing, infeasibility of loading, and difficulty in applying tension. Based on the problems found, the model is modified so that the processing model of the scaled node meets the experimental requirements, so that the truss structure node test can be carried out smoothly, and provides reliable experimental basis for the research and engineering application of truss structures.

[0023] 3. This invention solves the problem of how to apply tension to the rod by setting an eccentric bracket on the eccentric rod and a compression bracket on the crossbeam. The actuator applies a load to these two brackets, thus enabling the component to be subjected to tension and ensuring the comprehensiveness of the test.

[0024] 4. This invention sets up corresponding members and support plates of different types, and sets up a bracket for each member. The actuator provides power to the corresponding bracket, which can realize multi-point and multi-directional loading of the members of the truss structure node, making loading feasible. Attached Figure Description

[0025] Fig. 1 This is a schematic diagram of the overall structure of the present invention; Fig. 2 This is a top view of the overall structure of the present invention; Fig. 3 This is a schematic diagram of the overall structure of the present invention from another perspective; 1. Fixed bracket; 2. Compression bracket; 3. Eccentric bracket; 4. Actuator; 5. Crossbeam; 6. Fixed member; 7. Compression member; 8. Eccentric member; 9. Tension member; 10. Support; 11. Sealing plate; 12. Vertical plate; 13. Tension bracket. Detailed Implementation

[0026] 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, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0027] Example 1 A method for scale-down testing of truss structure nodes, the method comprising: S1. Construct a preliminary model of the scaled-down nodes based on the original truss structure nodes and the scale ratio; S2. Verify whether there are any problems after scaling down in the preliminary model of the scaled node. If there are no problems or the preliminary model of the scaled node is modified according to the problems after scaling down, then the preliminary model of the scaled node or the modified preliminary model of the scaled node is used as the processing model of the scaled node. S3. Place the scaled-down node machining model on the loading reaction frame; S4. Select either the compression loading method or the tension loading method to control the loading reaction frame and apply pressure or tension to the scaled node machining model.

[0028] The scaling ratio is determined based on processing feasibility, transportation convenience, and the loading capacity of the loading reaction frame.

[0029] If the original truss structure node has a large number of longitudinal stiffeners or a single longitudinal stiffener is thin, then the longitudinal stiffeners are merged.

[0030] If the cross-sectional dimensions in the preliminary model of the scaled node are too small, making it impossible to weld the last steel plate inside, then the cross-sectional dimensions are widened and a full penetration fillet weld is performed on the outside of the cross-section.

[0031] If the initial model of the scaled node has a large number of horizontal components, then the horizontal components are merged.

[0032] If the transverse components of the preliminary model of the scaled node cannot be welded, then depending on whether the transverse components are under tension or compression, they should be replaced with plug welding or polished and tightened.

[0033] In this embodiment, the scaling experiment method includes the following steps: 1. Scaled-down model design The original truss structure nodes are constructed, and a suitable scaling ratio is selected based on factors such as processing feasibility, transportation convenience, and the loading capacity of the loading equipment.

[0034] To address potential issues that may arise after scaling down, the following measures will be taken: (1) For the problem of excessively dense or thin longitudinal stiffeners in steel structure members, the stiffeners are merged according to the principle of stiffness equivalence to ensure that their spacing, thickness and other properties are machinable.

[0035] (2) For the problem that the last steel plate cannot be welded inside due to the small size of the closed section, the fillet weld is connected on the outside of the section after the section is appropriately widened.

[0036] (3) For transverse components such as diaphragms, the components are merged; and for the problem that the last weld after the last steel plate is closed cannot be welded, according to its tensile or compressive characteristics, the measures are changed to plug welding or grinding and tightening.

[0037] (4) To meet the requirements of the loading torque, a sealing plate is added to the end of the member.

[0038] 2. Scaled-down model loading reaction frame design Because the truss structure has a large number of connecting members at the nodes, and each member needs to be loaded, the existing reaction frame in the laboratory cannot achieve multi-point, multi-directional loading. Therefore, a loading reaction frame was designed, with the same configuration as the scaled-down model, but with its size enlarged by 1.1-1.2 times.

[0039] In the experiment, the scaled-down model was placed on the reaction frame, with only contact between the two and no connection, to ensure that the scaled-down model could deform freely during the loading test.

[0040] 3. Loading the scaled model For the truss structure, actuators were used to load the test model at the ends of the members. Both axial force and eccentric bending moment were considered during loading. The eccentric bending moment was achieved by correcting the point of application of the axial force, so that it was no longer aligned with the centroid of the section.

[0041] Example 2 like Figs. 1-3 As shown, an experimental apparatus for a scaled-down test method based on truss structure nodes includes a fixed bracket 1, a compression bracket 2, a tension bracket 13, an eccentric bracket 3, and an actuator 4. The scaled-down node fabrication model includes a beam section 5 and a member section having a fixed member 6, a compression member 7, an eccentric member 8, and a tension member 9. The loading reaction frame includes multiple support sections 10. The fixed bracket 1 and the fixed member 6 are connected and placed on the support section 10. The compression bracket 2 and the eccentric bracket 3 are both connected to the compression member 7 and the eccentric member 8 respectively via the actuator 4 and placed on the support section 10. The tension bracket 13 is connected to the support section 10 via the actuator 4. The tension member 9 is placed on the tension bracket 13 and the support section 10. The compression bracket 2 is connected to the beam section 5 via the actuator 4 and is set on the support section 10.

[0042] The fixed rod 6, the compression rod 7, the eccentric rod 8, and the tension rod 9 all include a sealing plate 11. The sealing plates 11 of the compression rod 7 and the eccentric rod 8 are connected to the actuator 4.

[0043] The device also includes a vertical plate 12, which is mounted on the support part 10 close to the eccentric bracket 3. The vertical plate 12, the pressure bracket 2, the actuator 4 and the crossbeam 5 are connected in sequence.

[0044] The upright plate 12 and the eccentric bracket 3 are located on the same support part 10.

[0045] In this embodiment, the model members are divided into two main categories: compression and tension, and different loading methods are used for each. (1) For the compression type, a sealing plate is added to the end of the model rod, and a compression bracket 2 is added to the side of the corresponding rod of the reaction frame. The sealing plate 11 and the compression bracket 2 are subjected to load through the actuator 4.

[0046] (2) For tension type, add eccentric bracket 3 to the end of the model rod and add compression bracket 2 to the side of the reaction frame. Apply load between the two brackets through actuator 4.

[0047] The fixed bracket 1 is used to limit the model so that it will not deviate when a torque is applied. During the compression test, the actuator 4 works to squeeze the sealing plate 11, thereby squeezing the corresponding compression member 7 to complete the compression test. During the tension test, a vertical plate 12 is set on the same support part 10 as the eccentric bracket 3, and a compression bracket 2 is set on the vertical plate 12. The compression bracket 2 and the eccentric bracket 3 form a height difference and an angle difference. The actuator 4 acts on the crossbeam part 5 and the eccentric member 8 respectively, so that the loading force on the model is in different directions and causes corresponding deformation, thereby simulating the tension.

[0048] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in the present invention, and these modifications or substitutions should all be covered within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A method for scaled-down testing of truss structure nodes, characterized in that, The method includes: S1. Construct a preliminary model of the scaled-down nodes based on the original truss structure nodes and the scale ratio; S2. Verify whether there are any problems after scaling down in the preliminary model of the scaled node. If there are no problems or the preliminary model of the scaled node is modified according to the problems after scaling down, then the preliminary model of the scaled node or the modified preliminary model of the scaled node is used as the processing model of the scaled node. S3. Place the scaled-down node machining model on the loading reaction frame; S4. Select either the compression loading method or the tension loading method to control the loading reaction frame and apply pressure or tension to the scaled node machining model.

2. The method for scale-down testing of truss structure nodes according to claim 1, characterized in that, The scaling ratio is determined based on processing feasibility, transportation convenience, and the loading capacity of the loading reaction frame.

3. The method for scale-down testing of truss structure nodes according to claim 1, characterized in that, If the original truss structure node has a large number of longitudinal stiffeners or a single longitudinal stiffener is thin, then the longitudinal stiffeners are merged.

4. The method for scale-down testing of truss structure nodes according to claim 1, characterized in that, If the cross-sectional dimensions in the preliminary model of the scaled node are too small, making it impossible to weld the last steel plate inside, then the cross-sectional dimensions are widened and a full penetration fillet weld is performed on the outside of the cross-section.

5. The method for scale-down testing of truss structure nodes according to claim 1, characterized in that, If the initial model of the scaled node has a large number of horizontal components, then the horizontal components are merged.

6. The method for scale-down testing of truss structure nodes according to claim 1, characterized in that, If the transverse components of the preliminary model of the scaled node cannot be welded, then depending on whether the transverse components are under tension or compression, they should be replaced with plug welding or polished and tightened.

7. An experimental apparatus based on the scaled-down test method for truss structure nodes as described in any one of claims 1-6, characterized in that, The model includes a fixed bracket (1), a compression bracket (2), a tension bracket (13), an eccentric bracket (3), and an actuator (4). The scaled-down node machining model includes a beam section (5) and a member section with fixed members (6), compression members (7), eccentric members (8), and tension members (9). The loading reaction frame includes multiple support sections (10). The fixed bracket (1) and the fixed member (6) are connected and placed on the support section (10). The compression leg (2) and the eccentric leg (3) are connected to the compression member (7) and the eccentric member (8) respectively through the actuator (4) and placed on the support part (10). The tension leg (13) is connected to the support part (10) through the actuator (4). The tension member (9) is placed on the tension leg (13) and the support part (10). The compression leg (2) is connected to the crossbeam part (5) through the actuator (4) and set on the support part (10).

8. The experimental apparatus according to claim 7, characterized in that, The fixed rod (6), the compression rod (7), the eccentric rod (8) and the tension rod (9) all include a sealing plate (11), and the sealing plate (11) of the compression rod (7) and the eccentric rod (8) is connected to the actuator (4).

9. The experimental apparatus according to claim 7, characterized in that, The device also includes a vertical plate (12), which is mounted on the support (10) close to the eccentric bracket (3). The vertical plate (12), the pressure bracket (2), the actuator (4) and the crossbeam (5) are connected in sequence.

10. The experimental apparatus according to claim 9, characterized in that, The upright plate (12) and the eccentric bracket (3) are located on the same support part (10).

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