Multi-span flexible slender structure vortex-induced vibration experiment device considering distributed elastic support

Abstract

The utility model relates to the field of ocean engineering physical model experiments, in particular to a multi-span flexible slender structure vortex-induced vibration experiment device considering distributed elastic support. The multi-span flexible slender structure vortex-induced vibration experimental device considering distributed elastic support comprises a rotating platform and a flexible slender structure located above the rotating platform. A transverse sliding rail is installed at the top of the rotating platform, and two transverse sliding grooves are formed in the upper surface of the transverse sliding rail in a penetrating mode. A transverse right sliding block and a transverse left sliding block are slidably connected to the two sides of the tops of the two transverse sliding grooves correspondingly. According to the multi-span flexible slender structure vortex-induced vibration experiment device and method considering the distributed elastic support provided by the utility model, the number of suspended sections of a flexible slender structure in an experiment system can be flexibly adjusted, so that the vortex-induced vibration response of multiple suspended sections under the action of complex sea conditions is researched; the method is of great significance to simulation of structures such as multi-span submarine cables in actual ocean engineering.

Description

Technical Field

[0001] The utility model relates to the field of marine engineering physical model experiments, in particular to a multi-span flexible slender structure vortex-induced vibration experimental device considering distributed elastic support. Background Art

[0002] Flexible, slender structures, such as submarine cables laid on the seabed, are located in a complex underwater environment. Due to factors such as water erosion or residual construction stress, continuous multi-span suspended sections that are not in direct contact with the seabed surface often appear. When the fluid flows around the suspended section of the structure, alternating vortices are formed on both sides of the pipe section. Due to the shedding of vortices, the structure is subjected to varying lift in its cross-flow direction. If the vortex shedding frequency, that is, the frequency of the lift acting on the structure, is close to a certain order of natural frequency of the flexible structure, the structure will "lock" and continuous vibration will easily cause fatigue damage to the structure. Due to the dynamic coupling of each span and the combined effect of nonlinear soil support boundaries, the dynamic response mechanism of multi-span submarine cables is very complex, and physical model experiments are urgently needed to conduct relevant research.

[0003] There are already some experimental devices and methods for vortex-induced vibration of flexible structures considering sag. Chinese patent CN112146837A discloses an experimental device and method for simulating the vibration-slapping coupling response of a submarine free-span pipe. The device can preset the structural tension and collect the tension data in real time during the experiment, and can also study the slapping effect between the structure and the seabed. Chinese patent CN112903245A discloses an experimental device and method for vortex-induced vibration of flexible slender structures considering sag effects. The device can adjust the different sags and heights of the structure to conduct vortex-induced vibration experiments on suspended submarine cables, and can constrain the horizontal displacement of the structural boundaries. In addition, Chinese patent CN114778071A proposes a submarine cable suspension device and experimental method for vortex-induced vibration tests of submarine cables, which can accurately adjust the height, length, inclination angle, and model diameter of the structure. However, the above patents are all single-span submarine cable vortex-induced vibration experimental devices that do not consider the influence of boundaries. However, for structures such as suspended-span submarine cables in reality, due to the complex and changeable seabed topography, multiple suspended-span sections with different lengths are often formed. There is a strong dynamic coupling between the suspended-span sections, and the nonlinear effect of the elastic support boundary of the soil is also strong.

[0004] Therefore, it is necessary to provide a new vortex-induced vibration experimental device and method for multi-span flexible slender structures considering distributed elastic support to solve the above technical problems. Summary of the Invention

[0005] In order to overcome the defects of the existing technology, a vortex-induced vibration experimental device for a multi-span flexible slender structure considering distributed elastic support is provided to solve the above problems.

[0006] The utility model provides a vortex-induced vibration experimental device and method for a multi-span flexible slender structure considering distributed elastic support, which include: a rotating platform, a flexible slender structure located above the rotating platform; a transverse slide rail is installed on the top of the rotating platform, and two transverse grooves are provided on the upper surface of the transverse slide rail; wherein, a transverse right slider and a transverse left slider are respectively slidably connected on both sides of the top of the two transverse grooves, and the tops of the transverse right slider and the transverse left slider are both provided with a system lifting adjustment device; a plurality of multi-span elastic support adjustment devices for supporting the flexible slender structure are provided on the top of the transverse slide rail between the two system lifting adjustment devices; a sag adjustment device is provided on the side relatively close to the two system lifting adjustment devices, and the sag of the flexible slender structure can be adjusted by the sag adjustment device; the system lifting adjustment device includes two vertical right slide rails installed on the top of the transverse right slider, two vertical left slide rails installed on the top of the transverse left slider, a vertical right slider slidably connected to both sides of the two vertical right slide rails, a vertical left slider slidably connected to both sides of the two vertical left slide rails, and fixing bolts for fixing the vertical right slider and the vertical left slider respectively.

[0007] Preferably, the system lifting and adjusting device also includes a crossbeam, and the crossbeam is located above the horizontal slide rail, and the two ends of the crossbeam are respectively located between the two vertical right slide rails and the vertical left slide rails, and the tops of the two vertical right slide rails and the two vertical left slide rails are both installed with fixing clips for fixing the crossbeam.

[0008] Preferably, the multi-span elastic support adjustment device includes a transverse slider slidably connected to the top of the transverse slide rail, and the bottom of the transverse slider is provided with two transverse slider guide rails that cooperate with the transverse slide groove. The top of the transverse slider is connected to a height adjustment platform, and the top of the height adjustment platform is installed with a rotating support. The top of the rotating support is connected to a square box, and openings are provided on both sides of the square box for the flexible slender structure to pass through. Flexible rings are installed on the openings, and the square box is filled with supporting fillers.

[0009] Preferably, the vertical adjustment device includes a transverse L-shaped plate connected to one side of the vertical left slider, and the transverse L-shaped plate is located on the side close to the vertical right slider, a pulley is installed on the top side of the transverse L-shaped plate through a bracket, and an axial sleeve is installed on the side of the top of the transverse L-shaped plate away from the pulley, and an axial limit sliding shaft is slidably connected inside the axial sleeve, and two sleeve top screws for fixing the axial limit sliding shaft are provided on the top of the axial sleeve.

[0010] Preferably, the bottom of the crossbeam is slidably connected to a dynamometer slider, and the bottom of the dynamometer slider is connected to a dynamometer, the bottom of the dynamometer is connected to a basket bolt, the bottom of the basket bolt is connected to a wire rope, and the end of the wire rope away from the basket bolt is connected to the axial limiting sliding shaft along the outside of the pulley.

[0011] Preferably, the side of the axial limiting sliding shaft away from the wire rope is connected to a left universal joint, and the side of the vertical right slider close to the axial limiting sliding shaft is connected to a right universal joint. The two ends of the flexible slender structure are respectively connected to the left universal joint and the right universal joint, and fastening screws are installed on the left universal joint and the right universal joint.

[0012] Preferably, the diameters of the opening and the flexible ring on the square box are larger than the diameter of the flexible elongated structure.

[0013] Preferably, the supporting filler is wet sand.

[0014] Compared with related technologies, the vortex-induced vibration experimental device and method for multi-span flexible slender structures considering distributed elastic supports provided by the present invention have the following beneficial effects:

[0015] The utility model can flexibly adjust the number of suspended sections of the flexible and slender structure in the experimental system, so as to study the vortex-induced vibration response of multiple suspended sections under complex sea conditions, which is of great significance for simulating structures such as multi-span submarine cables in actual marine engineering.

[0016] The utility model can realize the accurate simulation of the distributed elastic support boundaries of each suspended segment of the flexible slender structure, so as to study the dynamic response of multiple suspended segments under the influence of boundary conditions. It is of great value for understanding the influence of the nonlinear effect of the elastic support boundary of the soil on the dynamic response of the structure.

[0017] The utility model can flexibly adjust the span length and sag of each suspended section of the experimental system to study the dynamic coupling response of multi-span structures under uneven span length and sag, which is of great significance for simulating the changes in span length and sag caused by changes in seabed topography in actual engineering.

[0018] The utility model can flexibly adjust the height of the experimental system and the height difference between the left and right sides of each suspended section, so as to study the difference in structural dynamic response under different height differences on both sides of the suspended section. It is of great significance for simulating the height difference changes caused by the undulating seabed topography in actual engineering.

[0019] The utility model can flexibly adjust the angle between the experimental system and the incoming flow direction to study the difference in structural dynamic response under different incoming flow angles, which is of great significance for simulating the change in angle of attack caused by changes in water flow direction in actual marine engineering. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 A schematic structural diagram of a preferred embodiment of a vortex-induced vibration experimental device and method for a multi-span flexible slender structure considering distributed elastic support provided by the present invention;

[0021] Figure 2 for Figure 1 The structural diagram of the sag adjustment device shown;

[0022] Figure 3 for Figure 1 The structural diagram of the multi-span elastic support adjustment device shown;

[0023] Figure 4 for Figure 1 Schematic diagram of the structure of the basket bolt and the dynamometer shown.

[0024] Numbers in the figure: 101, crossbeam; 102, vertical right slide rail; 103, horizontal slide rail; 104, rotating platform; 105, horizontal right slider; 106, horizontal slide groove; 107, vertical right slider; 108, fixed clip; 109, vertical left slide rail; 110, vertical left slider; 111, horizontal left slider; 201, flexible slender structure; 202, square box; 203, height adjustment platform; 204, horizontal slider; 205, rotating base; 2 06. Flexible collar; 207. Support filler; 208. Horizontal slider guide; 301. Left universal joint; 302. Axial sleeve; 303. Pulley; 304. Wire rope; 305. Turnbuckle; 306. Tension gauge; 307. Fixing bolt; 308. Right universal joint; 309. Axial limit slide shaft; 310. Horizontal L-shaped plate; 311. Vertical slider guide; 312. Sleeve top screw; 313. Fastening screw; 314. Tension gauge slider. DETAILED DESCRIPTION

[0025] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0026] The specific implementation of the present invention is described in detail below with reference to specific embodiments.

[0027] The embodiment of the present invention provides a vortex-induced vibration experimental device for a multi-span flexible slender structure considering distributed elastic support, and the vortex-induced vibration experimental device and method for a multi-span flexible slender structure considering distributed elastic support include: a rotating platform 104, and a flexible slender structure 201 located above the rotating platform 104; a transverse slide rail 103 is installed on the top of the rotating platform 104, and two transverse slide grooves 106 are provided through the upper surface of the transverse slide rail 103; wherein, a transverse right slider 105 and a transverse left slider 111 are respectively slidably connected on both sides of the top of the two transverse slide grooves 106, and the tops of the transverse right slider 105 and the transverse left slider 111 are both provided with a system lifting adjustment device; the top of the transverse slide rail 103 is located at the two system A plurality of multi-span elastic support adjustment devices for supporting the flexible slender structure 201 are arranged between the system lifting adjustment devices; a sag adjustment device is arranged on the side relatively close to the two system lifting adjustment devices, and the sag of the flexible slender structure 201 can be adjusted by the sag adjustment device; the system lifting adjustment device includes two vertical right slide rails 102 installed on the top of the horizontal right slider 105, two vertical left slide rails 109 installed on the top of the horizontal left slider 111, a vertical right slider 107 slidably connected to both sides of the two vertical right slide rails 102, a vertical left slider 110 slidably connected to both sides of the two vertical left slide rails 109, and fixing bolts 307 for respectively fixing the vertical right slider 107 and the vertical left slider 110.

[0028] It should be noted that the transverse rail is mounted on the rotating platform 104. Two parallel transverse grooves 106 are provided on the upper surface of the transverse rail 103, extending left and right. The lower portions of the transverse left slider 111 and the transverse right slider 105 are provided with guide rails for use with the transverse grooves 106. The transverse left slider 111 and the transverse right slider 105 can slide laterally on the transverse rail 103 to adjust the overall span of the flexible, slender structure 201 to be tested. Rotating the bottom rotating platform 104 left and right can adjust the angle of attack of the water flow on the flexible, slender structure 201 to be tested. The system's lifting and adjusting device is primarily used to adjust the height of the experimental system. There are a set of guide rails on each side of the device (a vertical left rail 109 and a vertical right rail 102). Each rail is composed of two profiles. The two opposing surfaces on the left and right sides of the profile are provided with grooves extending vertically and extending vertically, as well as corresponding sliders (a vertical left slider 110 and a vertical right slider 107). The left and right slides each consist of two square plates with guide rails. The plates fit into grooves on the rails and are secured with screws 307 in four mounting holes at the four corners of the plates. To adjust the system height, simply loosen the screws, manually adjust the experimental system to the desired height, and then tighten the screws to secure.

[0029] In an embodiment of the present invention, the system lifting and adjusting device also includes a horizontal beam 101, and the horizontal beam 101 is located above the horizontal slide rail 103, and the two ends of the horizontal beam 101 are respectively located between the two vertical right slide rails 102 and the vertical left slide rail 109, and the tops of the two vertical right slide rails 102 and the two vertical left slide rails 109 are both installed with fixing clips 108 for fixing the horizontal beam 101.

[0030] It should be noted that the crossbeam 101, located above the transverse rails 103, serves as the top support structure for the entire lifting and adjustment device, providing horizontal stability and load-bearing capacity. The vertical right rail 102 and the vertical left rail 109 are located on the left and right sides of the crossbeam 101, respectively. Fixed clips 108 are installed on top of the vertical right rail 102 and the vertical left rail 109 to secure the crossbeam 101 and prevent it from loosening or shifting during sliding. Fixed clips 108 can be adjusted and fixed using bolts.

[0031] In an embodiment of the present invention, the multi-span elastic support adjustment device includes a transverse slider 204 that is slidably connected to the top of the transverse slide rail 103, and the bottom of the transverse slider 204 is provided with two transverse slider guide rails 208 that cooperate with the transverse slide groove 106. The top of the transverse slider 204 is connected to the height adjustment platform 203, and the top of the height adjustment platform 203 is installed with a rotating support 205. The top of the rotating support 205 is connected to the square box 202, and both sides of the square box 202 are provided with openings for the flexible slender structure 201 to pass through. Flexible rings 206 are installed on the openings, and the square box 202 is filled with support filler 207. The diameters of the openings and the flexible rings 206 on the square box 202 are larger than the diameter of the flexible slender structure 201, and the support filler 207 is wet sand.

[0032] It should be noted that the transverse slider 204 is slidably connected to the top of the transverse rail 103. A transverse slider guide 208 is provided at the bottom, which mates with the transverse groove 106. This provides horizontal sliding motion, allowing the entire device to move along the transverse rail 103, thereby adjusting its horizontal position. The height adjustment platform 203, connected to the top of the transverse slider 204, provides vertical height adjustment, allowing the rotating platform 205 and the box 202 to be raised or lowered as needed, thereby adjusting the height of the entire device. The box 202 is connected to the top of the rotating platform 205 and has openings on both sides for the flexible, elongated structure 201 to pass through. Flexible collars 206 are installed in these openings. The box 202 is filled with support filler 207 to provide elastic support and shock absorption. The openings on both sides of the box 202 and the flexible collars 206 provide multi-span connection and support, allowing the entire device to adapt to different installation environments and operating conditions. Flexible collar 206 protects flexible elongated structure 201, preventing it from being worn or damaged when passing through the opening. The diameters of both the opening in box 202 and flexible collar 206 are larger than the diameter of flexible elongated structure 201. The diameter of the opening needs to be large enough to allow flexible elongated structure 201 to pass through easily. The diameter of flexible collar 206 also needs to be larger than the diameter of flexible elongated structure 201 to ensure that flexible elongated structure 201 can pass through smoothly and provide a certain amount of space for movement and shock absorption. Support filler 207 is wet sand. Wet sand has a certain plasticity and can be shaped and adjusted as needed to adapt to different installation environments and working conditions. Wet sand also has certain shock absorption properties, which can absorb and disperse external impact forces, thereby improving the stability and reliability of the device.

[0033] In an embodiment of the present invention, the sag adjustment device includes a transverse L-shaped plate 310 connected to one side of the vertical left slider 110, and the transverse L-shaped plate 310 is located on a side close to the vertical right slider 107, a pulley 303 is installed on the top side of the transverse L-shaped plate 310 through a bracket, an axial sleeve 302 is installed on the side of the top of the transverse L-shaped plate 310 away from the pulley 303, the axial sleeve 302 is slidably connected to the axial limit sliding shaft 309, and two sleeve top screws 312 for fixing the axial limit sliding shaft 309 are provided on the top of the axial sleeve 302, the bottom of the crossbeam 101 is slidably connected to the dynamometer slider 314, and the dynamometer slider 314 is fixed to the axial limit sliding shaft 309. The bottom is connected to a dynamometer 306, the bottom of the dynamometer 306 is connected to a basket bolt 305, the bottom of the basket bolt 305 is connected to a steel wire rope 304, the end of the steel wire rope 304 away from the basket bolt 305 is connected to the axial limit slide 309 along the outside of the pulley 303, the side of the axial limit slide 309 away from the steel wire rope 304 is connected to the left universal joint 301, the side of the vertical right slider 107 close to the axial limit slide 309 is connected to the right universal joint 308, the two ends of the flexible slender structure 201 are respectively connected to the left universal joint 301 and the right universal joint 308, and fastening screws 313 are installed on both the left universal joint 301 and the right universal joint 308.

[0034] It should be noted that the sag adjustment device is based on the system's lifting device, with the addition of a left universal joint 301, a right universal joint 308, an L-shaped plate 310, an axial sleeve 302, a pulley 303, a wire rope 304, a turnbuckle 305, a dynamometer 306, and an axial limit slide 309. The sag adjustment device can further adjust the sag of the flexible, slender structure 201 while maintaining the stability of the experimental system, while also providing a connection point for the flexible, slender structure 201. The ends of the flexible, slender structure 201 are connected to the left universal joint 301 and the right universal joint 308, respectively. The center of the axial sleeve 302 is the axial limit slide 309, which has a set screw hole in its body and a sleeve set screw 312 installed in the set screw hole. The left universal joint 301 is directly connected to one end of the axial limit slide 309 via a fastening screw 313, while the other end of the axial limit slide 309 is connected to the wire rope 304. At the same time, the axial sleeve 302 is rigidly connected to the L-shaped steel plate 310 on the right side of the left slider. The right universal joint 308 is rigidly connected to the left side of the right slider 107. The wire rope 304 passes over the pulley 303 and is connected to the turnbuckle 305. The other end of the turnbuckle 305 is connected to the dynamometer 306. When adjusting the flexible, slender structure 201 to be tested, the sleeve screw 312 is loosened. After rotating the turnbuckle 305 to adjust the sag of each span of the flexible, slender structure 201 to be tested, the screw 312 is tightened to secure the axial limit slide shaft 309.

[0035] The above description is merely an embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made by using the contents of the description and drawings of the present invention, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A vortex-induced vibration experimental device for multi-span flexible slender structures considering distributed elastic supports, characterized in that: include: A rotating platform (104), and a flexible slender structure (201) located above the rotating platform (104); A transverse slide rail (103) is installed on the top of the rotating platform (104), and two transverse slide grooves (106) are provided through the upper surface of the transverse slide rail (103); Wherein, a right transverse slider (105) and a left transverse slider (111) are respectively slidably connected on both sides of the top of the two transverse sliding grooves (106), and a system lifting and lowering adjustment device is provided on the top of the right transverse slider (105) and the left transverse slider (111); The top of the transverse slide rail (103) is located between the two system lifting adjustment devices and is provided with a plurality of multi-span elastic support adjustment devices for supporting the flexible slender structure (201); A sag adjustment device is provided on a side relatively close to the two system lifting adjustment devices, and the sag of the flexible slender structure (201) can be adjusted by the sag adjustment device; The system lifting and adjusting device comprises two vertical right slide rails (102) installed on the top of the horizontal right slide rail (105), two vertical left slide rails (109) installed on the top of the horizontal left slide rail (111), a vertical right slide rail (107) slidably connected to both sides of the two vertical right slide rails (102), a vertical left slide rail (110) slidably connected to both sides of the two vertical left slide rails (109), and fixing bolts (307) for respectively fixing the vertical right slide rail (107) and the vertical left slide rail (110).

2. The vortex-induced vibration experimental device for multi-span flexible slender structures considering distributed elastic support according to claim 1 is characterized in that: The system lifting and adjusting device further comprises a crossbeam (101), and the crossbeam (101) is located above the transverse slide rail (103), and the two ends of the crossbeam (101) are respectively located between the two vertical right slide rails (102) and the vertical left slide rail (109), and the tops of the two vertical right slide rails (102) and the two vertical left slide rails (109) are both installed with fixing clips (108) for fixing the crossbeam (101).

3. The vortex-induced vibration experimental device for multi-span flexible slender structures considering distributed elastic support according to claim 2 is characterized in that: The multi-span elastic support adjustment device includes a transverse slider (204) slidably connected to the top of the transverse slide rail (103), and the bottom of the transverse slider (204) is provided with two transverse slider guide rails (208) that match the transverse slide groove (106), the top of the transverse slider (204) is connected to the height adjustment platform (203), and the top of the height adjustment platform (203) is installed with a rotating support (205), the top of the rotating support (205) is connected to the square box (202), and both sides of the square box (202) are provided with openings for the flexible slender structure (201) to pass through, and the openings are installed with flexible rings (206), and the square box (202) is filled with supporting fillers (207).

4. The vortex-induced vibration experimental device for multi-span flexible slender structures considering distributed elastic support according to claim 3 is characterized in that: The sag adjustment device includes a transverse L-shaped plate (310) connected to one side of the vertical left slider (110), and the transverse L-shaped plate (310) is located on a side close to the vertical right slider (107). A pulley (303) is installed on one side of the top of the transverse L-shaped plate (310) through a bracket. An axial sleeve (302) is installed on the side of the top of the transverse L-shaped plate (310) away from the pulley (303). An axial limiting sliding shaft (309) is slidably connected in the axial sleeve (302). Two sleeve top screws (312) for fixing the axial limiting sliding shaft (309) are provided on the top of the axial sleeve (302).

5. The vortex-induced vibration experimental device for multi-span flexible slender structures considering distributed elastic support according to claim 4 is characterized in that: The bottom of the crossbeam (101) is slidably connected to a dynamometer slider (314), and the bottom of the dynamometer slider (314) is connected to a dynamometer (306), the bottom of the dynamometer (306) is connected to a turnbuckle bolt (305), the bottom of the turnbuckle bolt (305) is connected to a steel wire rope (304), and one end of the steel wire rope (304) away from the turnbuckle bolt (305) is connected to an axial limiting sliding shaft (309) along the outer side of the pulley (303).

6. The vortex-induced vibration experimental device for multi-span flexible slender structures considering distributed elastic support according to claim 5, characterized in that: The side of the axial limit sliding shaft (309) away from the wire rope (304) is connected to a left universal joint (301), and the side of the vertical right sliding block (107) close to the axial limit sliding shaft (309) is connected to a right universal joint (308). The two ends of the flexible slender structure (201) are respectively connected to the left universal joint (301) and the right universal joint (308), and fastening screws (313) are installed on both the left universal joint (301) and the right universal joint (308).

7. The vortex-induced vibration experimental device for multi-span flexible slender structures considering distributed elastic support according to claim 6, characterized in that: The diameters of the openings on the square box (202) and the flexible collar (206) are greater than the diameter of the flexible elongated structure (201).

8. The vortex-induced vibration experimental device for multi-span flexible slender structures considering distributed elastic supports according to claim 7, characterized in that: The supporting filler (207) is wet sand.

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