A tooling device for fatigue testing of semi-U-rib orthotropic panel welded joints

Abstract

This utility model relates to a fixture for fatigue testing of a semi-U-rib orthotropic panel welded joint, comprising a base plate, a first connecting member, a second connecting member, a third connecting member, a first support base, and a second support base. The first support base is mounted on the base plate, and the web of the semi-U-rib specimen is fixedly connected to the first support base. The second support base is fixed to the first support base and extends to one side. The two flanges of the semi-U-rib specimen are respectively connected to the first and second connecting members. The first connecting member is slidably connected to the second support base via an up-and-down sliding mechanism. The second connecting member is used to connect to the upper fixture of the fatigue testing machine. The third connecting member is fixedly connected to the base plate and is used to connect to the lower fixture of the fatigue testing machine. This utility model reduces the size of the fixture, improves the testing accuracy and efficiency, and can accurately reproduce the stress state of the actual bridge, providing efficient support for fatigue assessment of welded joints.

Description

Technical Field

[0001] This utility model belongs to the field of bridge engineering technology, and in particular relates to a tooling device for fatigue testing of a semi-U-rib orthotropic panel welded joint. Background Technology

[0002] Orthotropic steel bridge decks, with their closed-joint stiffening system consisting of U-ribs welded to the top plate, offer advantages such as lightweight construction and high load-bearing capacity. However, under repeated bending stress from wheel loads, these welded joints are prone to various fatigue cracks, including weld root and weld toe cracks, becoming weak points in structural durability. Existing fatigue testing fixtures face multiple limitations: multi-U-rib tests require large-sized specimens, resulting in high material consumption and complex loading systems; while semi-U-rib models reduce specimen size, traditional fixtures, due to insufficient positioning accuracy, struggle to accurately simulate actual weld gaps, leading to loading eccentricity and distorted stress distribution. Furthermore, the oversimplification of boundary conditions in fixtures often overlooks the true stiffness characteristics of connection nodes, affecting the reliability of finite element analysis. This is especially true for novel variable-thickness U-rib structures, where traditional devices lack thickness adaptation and gradient control functions, failing to effectively verify design optimization effects. There is an urgent need to develop a dedicated fixture system with high-precision positioning, modular adjustability, and the ability to recreate complex boundaries to improve the simulation accuracy of fatigue tests under real service conditions.

[0003] Existing fatigue testing fixtures for orthotropic steel bridge deck welded joints suffer from the following drawbacks: traditional multi-U-rib tests require the fabrication of large-sized specimens, resulting in high material consumption and complex loading systems; the semi-U-rib model suffers from insufficient fixture positioning accuracy, leading to loading eccentricity and stress distribution deviating from actual working conditions; the fixture's boundary conditions are overly simplified, making it difficult to simulate the stiffness variation characteristics of actual structures; for novel variable-thickness U-rib structures, traditional devices lack adjustable mechanisms to adapt to different rib thicknesses and gradient changes, making it impossible to verify the design optimization effect; existing loading systems can only achieve uniaxial loading, failing to reproduce the coupling state of external bending and shear stress under wheel loads, resulting in significant differences between test results and actual bridge stress. This invention, through the integrated design of modular adjustable fixtures, high-precision positioning mechanisms, and a multi-axial composite loading system, solves the problems of poor specimen adaptability, stress simulation distortion, and simplified boundary conditions, significantly improving test accuracy and efficiency, and providing reliable technical support for the fatigue performance evaluation of welded joints. Utility Model Content

[0004] The technical problem to be solved by this utility model is to provide a tooling device for fatigue testing of semi-U-rib-orthotropic panel welded joints that can reduce tooling size and improve test accuracy and efficiency, in order to address the shortcomings of the existing technology.

[0005] The technical solution adopted in this utility model is as follows: a tooling device for fatigue testing of a semi-U-rib orthotropic panel welded joint, characterized in that it includes a base plate, a first connecting member, a second connecting member, a third connecting member, a first support base, and a second support base. The first support base is installed on the base plate, and the web of the semi-U-rib specimen is fixedly connected to the first support base. The second support base is fixed on the first support base and extends to one side. The two wing plates of the semi-U-rib specimen are respectively connected to the first connecting member and the second connecting member. The first connecting member is slidably connected to the second support base through an upper and lower sliding mechanism. The second connecting member is used to connect to the upper fixture of the fatigue testing machine. The third connecting member is fixedly connected to the base plate and is used to connect to the lower fixture of the fatigue testing machine.

[0006] According to the above technical solution, the first support includes at least two parallel elbow plates vertically fixedly disposed on the base plate, a support panel fixedly connected to the two elbow plates, and the web of the semi-U-rib specimen fixedly connected to the support panel.

[0007] According to the above technical solution, the second support base includes two parallel inclined braces fixedly connected to the support panel of the first support base, and two vertical sliding grooves are fixedly connected to the upper ends of the two inclined braces respectively, and the first connecting member is disposed between the two inclined braces.

[0008] According to the above technical solution, the upward and downward sliding mechanism includes a slider or roller connected to the first connecting member and extending to both sides, and the slider or roller is configured to slide upward and downward with the vertical sliding groove.

[0009] According to the above technical solution, the upward and downward sliding mechanism includes a shaft inserted through the first connecting member and rolling bearings arranged at both ends of the shaft, wherein the rolling bearings are configured to slide upward and downward with the vertical sliding groove.

[0010] According to the above technical solution, the first connector includes a first slot, and one end of one wing plate of the semi-U-rib specimen is fixedly connected to the first slot by a fastener.

[0011] According to the above technical solution, the second connector includes a second U-shaped slot, and the upper end of the second U-shaped slot is provided with an upper connecting plate for connecting with the fixture on the fatigue testing machine.

[0012] According to the above technical solution, the third connecting member includes a lower connecting plate provided at the lower end of the base plate. The lower connecting plate is used to connect with the lower fixture of the fatigue testing machine, and lower elbow plates are provided on both sides of the lower connecting plate.

[0013] According to the above technical solution, a counterweight block is also provided on the other side of the first support on the base plate.

[0014] According to the above technical solution, an oval hole is provided on the base plate, and the counterweight is fixed in the oval hole by fasteners.

[0015] The beneficial effects of this utility model are as follows: 1. This utility model fixes the semi-U-rib orthotropic bridge deck specimen model to the lower base of the testing fixture via a first support, and then to the testing machine via second and third connectors. Considering the actual stress characteristics of the U-rib structure, the left end of the model bridge top plate is fixedly connected via the first connector, and then placed in a vertically set slide groove via an up-and-down sliding mechanism. This restricts the horizontal displacement of the bridge top plate while ensuring vertical movement, which effectively simulates the stress characteristics of the actual U-rib. The right end of the bridge deck specimen (semi-U-rib specimen) is positioned by the second connector slot and then fixed by fasteners. The actuator clamping end of the fatigue testing machine applies vertical cyclic load through the second connector fastening the connecting plate, accurately simulating the actual stress mode of the welded joint of the U-rib orthotropic bridge deck. The tooling adopts a modular connection design. The upper and lower sliding mechanisms form a displacement adaptive compensation mechanism. The second connecting part is linked with the testing machine for loading. The overall structure is compact, the material consumption is low, the test process is simple, and the test data is obtained efficiently and intuitively. It reduces the tooling size, improves the test accuracy and efficiency, and can accurately reproduce the stress state of the real bridge, providing efficient support for fatigue assessment of welded joints.

[0016] 2. This utility model tooling is compact and saves materials, reducing site requirements; the snap-fit ​​bolt connection simplifies disassembly and assembly, and the adjustable counterweight improves the stability and safety of the test.

[0017] 3. This utility model can lower the equipment and testing threshold, is easy to operate and provides intuitive data acquisition, and greatly improves the efficiency of fatigue assessment. Attached Figure Description

[0018] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a three-dimensional axial schematic diagram of a tooling device for fatigue testing of a semi-U-rib orthotropic panel welded joint provided in an embodiment of this utility model.

[0020] Figure 2 This is a top view of a tooling device for fatigue testing of a semi-U-rib orthotropic panel welded joint provided in an embodiment of this utility model.

[0021] Figure 3 This is a bottom view of a tooling device for fatigue testing of a semi-U-rib orthotropic panel welded joint provided in an embodiment of this utility model. Detailed Implementation

[0022] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. The components of the embodiments of this application described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0023] like Figure 1-3 As shown, this embodiment provides a tooling device for fatigue testing of a semi-U-rib orthotropic panel welded joint. The U-rib specimen model in this embodiment includes a bridge top plate and its welded longitudinal rib web structure. The tooling device includes a base plate 7, a first connector, a second connector, a third connector, a first support base, and a second support base. The first support base is mounted on the base plate. The web of the semi-U-rib specimen 2 is fixedly connected to the first support base. The second support base is fixed to the first support base and extends to one side. The two flanges of the semi-U-rib specimen are respectively connected to the first connector and the second connector. The first connector is slidably connected to the second support base via an upward and downward sliding mechanism, forming an adjustable limiting structure to achieve adaptive displacement compensation of the specimen under load. The second connector is used to connect to the upper fixture of the fatigue testing machine, and the third connector is fixedly connected to the base plate and is used to connect to the lower fixture of the fatigue testing machine.

[0024] 4. In this invention, the semi-U-rib orthotropic bridge deck specimen model is fixed to the lower base of the testing fixture via a first support, and then fixed to the testing machine via second and third connectors. Considering the actual stress characteristics of the U-rib structure, the left end of the model bridge top plate is fixedly connected via the first connector, and then placed in a vertically set groove via an up-and-down sliding mechanism. This restricts the horizontal displacement of the bridge top plate while ensuring vertical movement, which effectively simulates the stress characteristics of the actual U-rib. The right end of the bridge deck specimen (semi-U-rib specimen) is positioned by the second connector slot and then fixed by fasteners. The actuator clamping end of the fatigue testing machine applies vertical cyclic load through the second connector fastening the connecting plate, accurately simulating the actual stress mode of the welded joint of the U-rib orthotropic bridge deck. The tooling adopts a modular connection design. The upper and lower sliding mechanisms form a displacement adaptive compensation mechanism. The second connecting part is linked with the testing machine for loading. The overall structure is compact, the material consumption is low, the test process is simple, and the test data is obtained efficiently and intuitively. It reduces the tooling size, improves the test accuracy and efficiency, and can accurately reproduce the stress state of the real bridge, providing efficient support for fatigue assessment of welded joints.

[0025] In this embodiment, the first support base includes a support panel 8. To reinforce the support panel 8, at least two parallel elbow plates 5 are provided on one side of the support panel 8. One end of each elbow plate 5 is fixedly connected to the support panel 8, wherein the elbow plates 5 are vertically fixedly mounted on the base plate 7. The web of the semi-U-rib specimen 2 is fixedly connected to the support panel 8. Specifically, bolt holes 11 are provided on the web, and bolts are inserted into the bolt holes 11 to fix the web of the semi-U-rib specimen 2 to the support panel 8.

[0026] The second support base includes two parallel diagonal braces 12 fixedly connected to the support panel 8. Two vertical sliding grooves 1 are fixedly connected to the upper ends of the two diagonal braces 12, and the first connecting member is disposed between the two diagonal braces 12. Specifically, an external connecting plate 9 is provided at the lower end of the diagonal brace 12. Bolt holes 10 are provided on the external connecting plate 9, and bolts are used to fix the diagonal brace and the external connecting plate to the support panel 8. This structure is more compact and has better robustness. A sliding groove 1 is provided at the upper end of the diagonal brace 12, and the upper and lower sliding mechanism is configured with the sliding groove 1.

[0027] The first connecting component includes a wing plate at one end of the semi-U-rib specimen 2, which is fixedly connected to the first U-shaped groove 13 by a fastener. Specifically, the upper and lower sliding mechanism is provided with a plurality of bolt holes 16, and bolts are set in the bolt holes 16 to fix one end of the wing plate of the semi-U-rib specimen to simulate the actual stress characteristics.

[0028] The upward and downward sliding mechanism includes a slider or roller connected to the first connecting member and extending to both sides. The slider or roller is configured to slide upward and downward with the vertical slide groove. In this embodiment, the upward and downward sliding mechanism includes a shaft 15 inserted through the first connecting member and rolling bearings 14 disposed at both ends of the shaft. The rolling bearings 14 are configured to slide upward and downward with the vertical slide groove 1. Considering the test characteristics and the stability of the overall tooling, the rolling bearings of the first connecting member are placed in the slide groove of the first support seat, and the two ends of the shaft extend out and are configured with the rolling bearings 14. During fatigue testing, it can slide up and down as the testing machine is loaded.

[0029] The second connector includes a second U-shaped groove 4, the upper end of which is provided with an upper connecting plate 3 for connecting to the fixture on the fatigue testing machine. Specifically, bolt holes 17 are provided at both the upper and lower ends of the second U-shaped groove 4, and bolts are installed in the bolt holes 17 to fix one end of the other wing plate of the semi-U-rib specimen. The top connecting plate of the first connector adopts a laterally extending structure, which forms an adaptive match with the clamping device of the fatigue testing machine to ensure the stability of the cyclic load application process.

[0030] In this embodiment, the two U-shaped slots are fixedly installed to the semi-U-rib specimen wing plate (bridge deck) by bolt connection, which effectively avoids the generation of fatigue cracks in the corner area and has the advantage of being detachable.

[0031] The third connecting member includes a lower connecting plate 22 provided at the lower end of the base plate. The lower connecting plate 22 is used to connect with the lower fixture of the fatigue testing machine. Lower elbow plates 21 are provided on both sides of the lower connecting plate 22.

[0032] A counterweight 17 is also provided on the other side of the base plate, located on the first support. The counterweight can be adjusted according to the size of different semi-U-rib specimens, making the semi-U-rib orthotropic bridge deck specimen model more stable under vertical loads and improving the safety of the testing fixture. Specifically, the counterweight 6 is fixed to the base plate 7 by bolts passing through bolt holes 18 and oval holes 19. Example 2: In this embodiment, because semi-U-rib specimens of different sizes were selected, the opening widths of the corresponding slots of the first U-shaped slot 13 and the second U-shaped slot 4 were adjusted accordingly. At the same time, the size and thickness of the base plate 7 were also adjusted accordingly. With the help of the appropriate adjustment of the counterweight 6, a stable and accurate tooling test system was obtained. The second connector was connected to the fixture on the fatigue testing machine through the upper connecting plate 3, thereby vertically loading the modified and adjusted semi-U-rib-orthotropic bridge panel specimen model 2 to simulate the actual panel stress characteristics, which ensured the accuracy of the test.

[0033] The embodiments described above are some, but not all, of the embodiments of this application. The detailed description of the embodiments of this application is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

Claims

1. A tooling device for fatigue testing of a semi-U-rib orthotropic panel welded joint, characterized in that: The device includes a base plate, a first connector, a second connector, a third connector, a first support base, and a second support base. The first support base is mounted on the base plate. The web of the semi-U-rib specimen is fixedly connected to the first support base. The second support base is fixed to the first support base and extends to one side. The two wing plates of the semi-U-rib specimen are respectively connected to the first connector and the second connector. The first connector is slidably connected to the second support base through an up-and-down sliding mechanism. The second connector is used to connect to the upper fixture of the fatigue testing machine. The third connector is fixedly connected to the base plate and is used to connect to the lower fixture of the fatigue testing machine.

2. The tooling apparatus for fatigue testing of the semi-U-rib orthotropic panel welded joint according to claim 1, characterized in that: The first support includes at least two parallel elbow plates vertically fixedly mounted on the base plate, and a support panel fixedly connected to the two elbow plates. The web of the semi-U-rib specimen is fixedly connected to the support panel.

3. The tooling apparatus for fatigue testing of the semi-U-rib orthotropic panel welded joint according to claim 1 or 2, characterized in that: The second support includes two parallel diagonal braces fixedly connected to the support panel of the first support. Two vertical sliding grooves are fixedly connected to the upper ends of the two diagonal braces respectively. The first connector is disposed between the two diagonal braces.

4. The tooling apparatus for fatigue testing of the semi-U-rib orthotropic panel welded joint according to claim 3, characterized in that: The sliding mechanism includes a slider or roller connected to the first connector and extending to both sides, the slider or roller being configured to slide up and down with a vertical slide groove.

5. The tooling apparatus for fatigue testing of the semi-U-rib orthotropic panel welded joint according to claim 4, characterized in that: The sliding mechanism includes a shaft inserted through a first connector and rolling bearings disposed at both ends of the shaft, the rolling bearings being configured to slide up and down with a vertical sliding groove.

6. The tooling apparatus for fatigue testing of the semi-U-rib orthotropic panel welded joint according to claim 1 or 2, characterized in that: The first connector includes a first slot, and one end of one wing plate of the semi-U-rib specimen is fixedly connected to the first slot by a fastener.

7. The tooling apparatus for fatigue testing of the semi-U-rib orthotropic panel welded joint according to claim 1 or 2, characterized in that: The second connector includes a second U-shaped slot, and the upper end of the second U-shaped slot is provided with an upper connecting plate for connecting to the fixture on the fatigue testing machine.

8. The tooling apparatus for fatigue testing of the semi-U-rib orthotropic panel welded joint according to claim 1 or 2, characterized in that: The third connecting member includes a lower connecting plate provided at the lower end of the base plate. The lower connecting plate is used to connect with the lower fixture of the fatigue testing machine. Lower elbow plates are provided on both sides of the lower connecting plate.

9. The tooling apparatus for fatigue testing of the semi-U-rib orthotropic panel welded joint according to claim 1 or 2, characterized in that: A counterweight is also provided on the other side of the first support on the base plate.

10. The tooling apparatus for fatigue testing of the semi-U-rib orthotropic panel welded joint according to claim 9, characterized in that: An oval hole is provided on the base plate, and the counterweight is fixed in the oval hole by fasteners.

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