An offshore wind turbine foundation torsion test device

Abstract

The present invention relates to the technical field of single pile testing, and in particular to an offshore wind turbine foundation torsion test device. An offshore wind turbine foundation torsion test device comprises: a reaction frame, provided with a bottom plate, a first column and a model box are fixedly provided on the bottom plate, and the model box is suitable for accommodating a saturated soil layer; a single pile, partially inserted into the saturated soil layer; a force-applying component, including a force-applying member, the force-applying member is parallel to the bottom plate, and the force-applying member is fixedly connected to the first column; a force transmission component is arranged between the force-applying component and the single pile, and comprises a force transmission frame, one end of the force transmission frame is connected to the force-applying member, and the other end of the force transmission frame is fixedly connected to the single pile, and the force transmission frame converts the force transmitted by the force-applying member into a rotational force applied to the single pile, so that the single pile rotates periodically along its own circumferential direction. The present invention solves the problem that the existing single pile testing device can only carry out a force test of a traditional anchor foundation subjected to a certain force, and cannot carry out torque analysis, thereby providing an offshore wind turbine foundation torsion test device.

Description

Technical Field

[0001] The invention relates to the technical field of single pile testing, and in particular to an offshore wind turbine foundation torsion resistance testing device. Background Art

[0002] The mooring system is the key to offshore floating wind turbines resisting wind and wave loads, and the bearing performance analysis of the anchor foundation is the basis for the research on the reliability, safety and economic applicability of floating wind turbines. Due to the advantages of fast construction, low installation noise, no need for pretreatment of the formation, easy recovery, and applicability to deep water, the suction cylinder anchor foundation is widely used in the offshore oil and gas industry, and with the development of marine renewable energy, it is gradually being used in offshore wind farm construction. According to the 2022 Offshore Wind Energy Market Report of the U.S. Department of Energy's Wind Energy Technology Division, as of the end of 2021, floating wind turbine foundations accounted for only 0.2% of the world's built offshore wind turbine foundations, but in the global planned offshore wind turbine market, the share of floating wind turbine foundations will increase to 20.3%. In order to better improve the economic applicability of floating wind power, many scholars have proposed the concept of shared anchoring foundations, that is, one anchoring foundation provides anchoring force to multiple wind turbine platforms at the same time, and pointed out that the total tensile force on the shared anchoring foundation is smaller than that on the traditional anchoring foundation, but the shared anchoring foundation increases the interconnectivity of the entire wind farm. Once an anchoring foundation is damaged or dismantled, the remaining anchoring foundations will be affected, which may induce the failure of the remaining anchoring foundations and reduce the reliability of the system.

[0003] Generally speaking, traditional anchor foundations only provide anchoring force for a single wind turbine platform. For traditional anchor foundations, the force F1 acting on the suction bucket anchor point on paper may not pass through the axis (point O), and there is an angle α between the anchor point and the radial direction. Therefore, F1 can be equivalent to the force and torque acting on the axis. For shared anchor foundations, assuming that the angles between the forces and the radial direction at the three anchor points are α and equal in magnitude, the torque is superimposed to three times that of the traditional anchor foundation, and the horizontal resultant force is reduced to zero, which puts higher requirements on the torsional shear bearing performance of the anchor foundation. Therefore, under the action of static force, the shared foundation may fail in torsion, affecting the safe and stable operation of offshore wind turbines. In addition, under the combined effect of wind, wave, and ocean current loads, the output F and angle α of each anchor point change periodically with time. On the whole, the total torque received by the foundation during the operation period is a periodic load. Under the action of multiple load cycles, the permanent torsional deformation of the foundation gradually accumulates, affecting the long-term performance of offshore wind turbines. The existing single pile testing device can only carry out stress tests on traditional anchor foundations subjected to a certain force, but cannot perform torque analysis. Summary of the invention

[0004] Therefore, the technical problem to be solved by the present invention is to overcome the defect that the single pile testing device in the prior art can only carry out stress test of the traditional anchor foundation subjected to a certain force and cannot perform torque analysis, thereby providing an offshore wind turbine foundation torsion test device.

[0005] In order to solve the above problems, the present invention provides an offshore wind turbine foundation torsion test device, comprising:

[0006] A reaction frame, wherein the reaction frame is provided with a bottom plate, a first column and a model box are fixedly provided on the bottom plate, and the model box is suitable for accommodating a saturated soil layer;

[0007] A monopile, wherein the monopile is partially inserted into a saturated soil layer;

[0008] A force-applying assembly, the force-applying assembly comprising a force-applying member, the force-applying member is parallel to the bottom plate, and the force-applying member is fixedly connected to the first column;

[0009] A force transmission component is arranged between the force-applying component and the single pile. The force transmission component includes a force transmission frame, one end of which is connected to the force-applying member, and the other end of which is fixedly connected to the single pile. The force transmission frame converts the force transmitted by the force-applying member into a rotational force applied to the single pile, so that the single pile rotates periodically along its own circumferential direction.

[0010] Optionally, the force-applying component further includes a rack, and the protruding end of the force-applying member is fixedly connected to the rack. The force-transmitting component further includes a gear, and the gear is fixedly connected to the force-transmitting frame, and the gear is meshed with the rack.

[0011] Optionally, the force transmission frame is a square frame structure, a joint cap is provided in the force transmission frame, the joint cap is fixedly connected to the single pile, and the joint cap is slidably connected to the force transmission frame.

[0012] Optionally, a baffle is provided in the force transmission frame.

[0013] Optionally, it further comprises a limiting bracket, which is fixedly connected to the model box, the force transmission frame is partially arranged in the limiting bracket, and the single pile is fixedly connected to the joint cap after passing through the sleeve of the limiting bracket.

[0014] Optionally, it comprises a cross beam and a second column, wherein the cross beam is fixedly connected to the first column and the second column respectively, and the force-applying assembly is arranged below the cross beam.

[0015] Optionally, a connecting plate is further included, wherein the connecting plate is arranged between the force applying member and the cross beam, and the force applying member is arranged below the connecting plate.

[0016] Optionally, a support seat is provided on the surface of the connecting plate facing the force transmission frame, and the support seat is slidably connected to the rack.

[0017] Optionally, a controller is also included, and the controller is connected to the force applying member circuit.

[0018] Optionally, a centrifuge is further included, wherein a hanging basket is provided in the centrifuge, the reaction frame is fixed in the hanging basket, and the centrifuge is connected to a controller circuit.

[0019] The technical solution of the present invention has the following advantages:

[0020] 1. The torsion resistance test device for offshore wind turbine foundation provided by the present invention comprises: a reaction frame provided with a bottom plate, a first column and a model box are fixedly provided on the bottom plate, and the model box is suitable for accommodating a saturated soil layer; a single pile, which is partially inserted into the saturated soil layer; a force-applying component, including a force-applying member parallel to the bottom plate, and the force-applying member is fixedly connected to the first column; a force transmission component, which is arranged between the force-applying component and the single pile, and the force transmission component comprises a force transmission frame, one end of the force transmission frame is connected to the force-applying member, and the other end is fixedly connected to the single pile, and the force transmission frame converts the force transmitted by the force-applying member into the rotational force of the single pile, so that the single pile rotates periodically along its own circumferential direction, thereby simulating the periodic load received by the single pile when it is used as a shared foundation, so as to accurately judge the torsional shear bearing capacity of the prototype offshore wind turbine foundation, help test personnel master the interaction relationship between the cylinder and the soil under the torsional shear load in the supergravity model test, and better optimize the design parameters of the shared foundation.

[0021] 2. The offshore wind turbine foundation torsion test device provided by the present invention, the force-applying component also includes a rack, the protruding end of the force-applying member is fixedly connected to the rack, the force transmission component also includes a gear, the gear is fixedly connected to the force transmission frame, the gear and the rack are meshingly arranged to convert the linear motion of the force-applying member into the rotation of the force transmission frame, and then the force transmission frame drives the single pile to rotate.

[0022] 3. The offshore wind turbine foundation torsion test device provided by the present invention has a force transmission frame with a square frame structure. A joint cap is provided in the force transmission frame. The joint cap is fixedly connected to the single pile, and the joint cap is slidably connected to the force transmission frame. The fixed connection with the single pile is achieved through the joint cap, and the sliding of the joint cap and the force transmission frame is used to prevent the single pile from being unable to move relative to the force transmission frame.

[0023] 4. In the offshore wind turbine foundation torsion test device provided by the present invention, a baffle is provided in the force transmission frame to limit the joint cap.

[0024] 5. The offshore wind turbine foundation torsion test device provided by the present invention also includes a limit bracket, which is fixedly connected to the model box. The force transmission frame is arranged in the limit bracket. The single pile passes through the sleeve of the limit bracket and is fixedly connected to the joint cap. The sleeve is used to limit the horizontal movement of the single pile so that the single pile can only rotate along its own circumference.

[0025] 6. The offshore wind turbine foundation torsion test device provided by the present invention includes a cross beam and a second column, the cross beam is fixedly connected to the first column and the second column respectively, the force-applying component is arranged under the cross beam, and the cross beam is used to strengthen the reaction frame structure.

[0026] 7. The offshore wind turbine foundation torsion test device provided by the present invention also includes a connecting plate, which is arranged between the force-applying member and the cross beam, and the force-applying member is arranged below the connecting plate, and the connecting plate plays a connecting role.

[0027] 8. In the offshore wind turbine foundation torsion test device provided by the present invention, the controller is connected to the force-applying member circuit to control the movement of the force-applying member to drive the rack to move. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0029] Figure 1 A schematic diagram of an offshore wind turbine foundation torsion test device provided in an embodiment of the present invention;

[0030] Figure 2 A schematic diagram of the connection between the model box, the force applying component and the force transmitting component provided in an embodiment of the present invention;

[0031] Figure 3 A schematic diagram of the connection between the connecting plate, the force applying assembly and the gear provided in an embodiment of the present invention;

[0032] Figure 4 A schematic diagram of the connection between a force transmission component and a monopile provided in an embodiment of the present invention;

[0033] Figure 5 A schematic diagram of a force transmission frame provided in an embodiment of the present invention;

[0034] Figure 6 It is a schematic diagram of a limiting bracket provided in an embodiment of the present invention.

[0035] Explanation of the reference numerals in the accompanying drawings: 1. cross beam; 2. first column; 3. model box; 4. second column; 5. force-applying member; 6. rack; 7. support seat; 8. connecting plate; 9. gear; 10. force transmission frame; 11. limit bracket; 12. sleeve; 13. single pile; 14. baffle; 15. joint cap; 16. first cross bar; 17. second cross bar; 18. bottom plate; 19. bearing. DETAILED DESCRIPTION

[0036] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0037] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0038] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0039] In addition, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0040] like Figure 1 A specific implementation of the offshore wind turbine foundation torsion test device shown in -6 includes: a reaction frame, and a force-applying component and a force-transmitting component arranged in the reaction frame.

[0041] like Figure 1 , Figure 2 As shown, the reaction frame includes a bottom plate 18, and a first column 2, a second column 4 and a model box 3 fixed thereon, wherein the model box 3 is arranged at the center of the bottom plate 18, and the model box 3 is suitable for accommodating a saturated soil layer. The number of the first columns 2 is two, and the number of the second columns 4 is two. The first columns 2 and the second columns 4 enclose a rectangular space, and the model box 3 is arranged in the rectangular space. Figure 1As shown, a cross beam 1 is provided between the first column 2 and the second column 4, that is, the cross beam 1 is provided corresponding to the model box 3, the upper ends of the adjacent first columns 2 and the second columns 4 are connected by a first cross bar 16, and the lower ends of the adjacent first columns 2 and the second columns 4 are connected by a second cross bar 17, so as to enclose a frame structure. Figure 1 , Figure 4 As shown, it also includes a single pile 13 with a hollow structure, wherein the single pile 13 is partially inserted into the saturated soil layer.

[0042] like Figure 2 , Figure 3 As shown, a force-applying assembly is provided below the cross beam 1, and the force-applying assembly includes a force-applying member 5, a rack 6 and two support seats 7, wherein the force-applying member 5 is fixedly connected to the cross beam 1, and a connecting plate 8 is provided between the support seat 7 and the cross beam 1, and the connecting plate 8 is fixedly connected to the cross beam 1 and the support seat 7, respectively, and a spacing is left between the two support seats 7, and the telescopic end of the force-applying member 5 is fixedly connected to the rack 6, and the rack 6 is slidably connected to the support seat 7, that is, the telescopic end of the force-applying member 5 drives the rack 6 to move along the length direction, and the support seat 7 is used to limit the rack 6 from shaking arbitrarily, so that the rack 6 can only move along its own length direction. Specifically, the force-applying member 5 is a servo motor.

[0043] like Figure 3 , Figure 4 As shown, the force transmission component is arranged between the force application component and the single pile 13, and the force transmission component includes a force transmission frame 10, which is a square frame structure. A joint cap 15 is arranged inside the force transmission frame 10, and the joint cap 15 is fixedly connected to the single pile 13, and the joint cap 15 is slidably connected to the force transmission frame 10. Figure 3 , Figure 4 As shown, the force transmission assembly also includes a gear 9, which is fixedly connected to the force transmission frame 10, and the gear 9 is meshed with the rack 6, that is, one end of the force transmission frame 10 is fixedly connected to the gear 9, and the other end is connected to the single pile 13. Figure 4 As shown, a baffle 14 is also provided in the force transmission frame 10, that is, the baffle 14 is fixedly connected to the force transmission frame 10. At the same time, a layer of PTFE coating is sprayed on the square inner wall of the force transmission frame 10 to reduce the friction between the joint cap 15 and the force transmission frame 10. To fix the gear 9, as shown in FIG. Figure 3 , Figure 4 As shown, the gear 9 is fixedly connected to the bearing 19 and the force transmission frame 10 respectively, that is, the bearing 19 is located below the cross beam 1, and the bearing 19 is connected to the gear 9 after passing through the through hole of the connecting plate 8, and the force transmission frame 10 is fixedly connected to the gear 9 by bolts.

[0044] like Figure 1 , Figure 2 As shown, it also includes a limiting bracket 11, which is fixedly connected to the model box 3, and the force transmission frame 10 is partially arranged in the limiting bracket 11. Figure 4, Figure 5 and Figure 6 As shown, the single pile 13 passes through the sleeve 12 of the limit bracket 11 and is fixedly connected with the joint cap 15, wherein the limit bracket 11 is fixedly connected with the sleeve 12. It should be noted that the end of the joint cap 15 extends into the single pile 13 and is fixedly connected by bolts. Specifically, the sleeve 12 is made of a polytetrafluoroethylene sleeve 12, and the friction coefficient between the polytetrafluoroethylene sleeve 12 and the single pile 13 is very small and can be ignored, so as to reduce the rotational obstruction of the sleeve 12 to the single pile 13.

[0045] In order to facilitate measurement, a measuring assembly is also included, which includes four strain gauges, which are arranged at an angle of ±45° to the vertical direction at the part of the single pile 13 that is higher than the saturated soil layer, that is, the angle between the sticking angle of the strain gauge and the central axis of the single pile 13 is 45°, so as to measure the strain of the single pile 13 in the ±45° direction, and convert it into the torque on the top of the single pile 13 through the corresponding algorithm. In addition, a connecting rod facing the inside of the box is provided at the top of the model box 3, and a laser displacement sensor facing the force transmission frame 10 is provided at the end of the connecting rod, and the laser displacement sensor includes a laser emitting part and a laser receiving part.

[0046] For the convenience of control, it also includes a controller and a centrifuge. A hanging basket is arranged in the centrifuge, and a reaction frame is fixed in the hanging basket. The controller is respectively connected with the strain gauge, the force applying member 5, the laser displacement sensor and the centrifuge circuit.

[0047] In the specific implementation process, during the installation process, the single pile 13 is first passed through the casing 12 and then fixedly connected to the joint cap 15, and then the gear 9 is fixedly connected to the bearing 19 and the force transmission frame 10 respectively. After the bottom of the single pile 13 reaches the top of the saturated soil layer, a distance is left between the baffle 14 and the joint cap 15, and a jack is placed between the baffle 14 and the joint cap 15. The baffle 14 is used as a support so that the jack pushes the single pile 13 to a preset depth in the saturated soil layer. During the test, after the centrifuge is started, the reaction frame located in the hanging basket is in a super gravity state as a whole, that is, the state of the saturated soil layer near the single pile 13 in the hanging basket is the same as the state of the saturated soil layer near the single pile 13 on the seabed. Based on the similarity theory of centrifugal model test, the controller controls the telescopic end of the force-applying member 5 to drive the rack 6 to reciprocate according to the preset numerical value. Through the cooperation of the rack 6 and the gear 9, the horizontal movement is converted into the torsional rotation movement of the gear 9, and then simulated as the rotation of the foundation of the single pile 13, and the simulation of the periodic torsional cycle load is carried out. The sensor structure is connected with the controller signal, and the direction and magnitude of the force of the force-applying member 5 are continuously fed back respectively, so as to accurately simulate the load effect on the single pile 13 in the real marine environment. With the increase of the test time and the increase of the number of cyclic loads, the single pile 13 is subjected to the force, which causes the saturated soil layer near the pile foundation to change, and the pile body tilts. The strain sensor promptly transmits the change signal to the controller, thereby helping the test personnel to understand the change process in time, so as to obtain simulation results close to the real working conditions.

[0048] As an alternative implementation, the force applying member 5 may also be a telescopic oil cylinder, a telescopic air cylinder or the like.

[0049] As an alternative embodiment, the force applying member 5 can also be a combination of a motor and a driving gear 9, that is, the force applying member 5 drives the driving gear 9 to rotate, and then the driving gear 9 drives the passive gear 9 on the force transmission frame 10 to rotate, thereby realizing the rotation of the force transmission frame 10.

[0050] Obviously, the above embodiments are merely examples for clear explanation, and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived from them are still within the protection scope of the invention.

Claims

1. An offshore wind turbine foundation torsion test device, characterized in that: include: A reaction frame, the reaction frame being provided with a bottom plate (18), a first column (2) and a model box (3) being fixedly provided on the bottom plate (18), wherein the model box (3) is suitable for accommodating a saturated soil layer; A single pile (13), wherein the single pile (13) is partially inserted into a saturated soil layer; A force-applying assembly, the force-applying assembly comprising a force-applying member (5), the force-applying member (5) being parallel to the bottom plate (18), and the force-applying member (5) being fixedly connected to the first column (2); A force transmission component, the force transmission component is arranged between the force application component and the single pile (13), the force transmission component comprises a force transmission frame (10), one end of the force transmission frame (10) is connected to the force application member (5), and the other end of the force transmission frame (10) is fixedly connected to the single pile (13), and the force transmission frame (10) converts the force transmitted by the force application member (5) into a rotational force applied to the single pile (13), so that the single pile (13) rotates periodically along its own circumferential direction; The force applying component also includes a rack (6), the protruding end of the force applying member (5) is fixedly connected to the rack (6), and the force transmission component also includes a gear (9), the gear (9) is fixedly connected to the force transmission frame (10), and the gear (9) is meshed with the rack (6); The force transmission frame (10) is a square frame structure, a joint cap (15) is provided inside the force transmission frame (10), the joint cap (15) is fixedly connected to the single pile (13), and the joint cap (15) is slidably connected to the force transmission frame (10); It also comprises a limiting bracket (11), the limiting bracket (11) is fixedly connected to the model box (3), the force transmission frame (10) is partially arranged in the limiting bracket (11), and the single pile (13) passes through the sleeve (12) of the limiting bracket (11) and is fixedly connected to the joint cap (15); It comprises a cross beam (1) and a second column (4), wherein the cross beam (1) is fixedly connected to the first column (2) and the second column (4) respectively, and the force-applying component is arranged below the cross beam (1); It also comprises a connecting plate (8), wherein the connecting plate (8) is arranged between the force applying member (5) and the cross beam (1), and the force applying member (5) is arranged below the connecting plate (8).

2. The offshore wind turbine foundation torsion test device according to claim 1 is characterized in that: A baffle (14) is provided inside the force transmission frame (10).

3. The offshore wind turbine foundation torsion test device according to claim 1 is characterized in that: A support seat (7) is provided on the surface of the connecting plate (8) facing the force transmission frame (10), and the support seat (7) is slidably connected to the rack (6).

4. The offshore wind turbine foundation torsion test device according to claim 3 is characterized in that: It also includes a controller, which is connected to the force applying member (5) through a circuit.

5. The offshore wind turbine foundation torsion test device according to claim 4 is characterized in that: It also includes a centrifuge, in which a hanging basket is arranged, the reaction frame is fixed in the hanging basket, and the centrifuge is connected with a controller line.

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