Damping and self-resetting friction column base node of wind power tower drum

Abstract

The invention relates to the technical field of wind power generation buildings, and provides a damping self-resetting friction column base joint of a wind power tower. Comprising a steel bottom plate foundation, a swinging friction column base node, a polyethylene coating friction pair and a pre-tightening force control device. The steel bottom plate foundation is fixed on a site, the swing friction column base node is designed to be connected between the wind power tower drum and the steel bottom plate foundation, and the polyethylene coating material is plated on the stepped friction surface and is connected through the galvanized pretightening force control device. Circumferential friction pairs are arranged at the connecting positions of the steel bottom plate foundation and the column feet at equal intervals so as to limit the maximum shearing force and upsetting moment of the connecting positions of the column feet. By means of the characteristic of symmetrical friction connection and the swing self-resetting mechanism, the overall stability of the structure is improved, dissipation of earthquake energy is achieved, meanwhile, self-resetting of the tower drum after an earthquake is achieved by means of the pre-tightening force control device and the gravity action of the structure, and finally a low-damage wind power tower drum structure system is formed.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of wind power generation construction technology, in particular to a damping self-resetting wind power tower friction column foot joint. BACKGROUND

[0002] The wind power tower is a core load-bearing component supporting the wind turbine, and the stress performance of the column foot area of the wind power tower is directly related to the safety and durability of the overall structure under seismic load. Under strong earthquake action, the bottom of the tower often bears huge bending moment and shear force, and the traditional rigid connection column foot is prone to brittle failure such as concrete crushing or anchor bolt yielding, resulting in loss of structure function and difficulty in repair. At present, in order to improve the seismic performance, a seismic isolation layer is often arranged at the foundation interface to make the tower and the foundation produce relative displacement, thereby prolonging the structure period and dissipating seismic energy. However, the wind power tower belongs to a high-soft structure, and this method has limited effect on the control of seismic response caused by high-order modes, and the upper part of the tower body may still be seriously damaged due to dynamic response amplification. Therefore, a column foot joint form with friction energy dissipation mechanism and post-earthquake self-resetting function is studied to control the internal force above the foundation and effectively limit the development of overall structural damage. SUMMARY

[0003] The present application aims to provide a damping self-resetting wind power tower friction column foot joint, which comprises a steel bottom plate foundation fixed to the ground, a wind power tower column foot placed on the upper surface of the base, eight stiffening ribs fixed to the base and arranged in the circumferential direction of the wind power tower, eight stiffening ribs fixed to the tower and arranged in the circumferential direction of the wind power tower, a friction outer cover plate attached to the two sides of the column foot stiffening rib, a pre-tightening force control device connecting the friction outer cover plate and the stiffening rib and providing pre-tightening force, and a friction pair composed of the pre-tightening force control device, the friction outer cover plate and the two sides of the stiffening rib. The friction outer cover plate is provided with a standard bolt hole, and the stiffening rib is provided with a vertical long slot hole or a large circular hole to ensure that the support can slide smoothly when subjected to load and dissipate energy through friction. The size of the bolt hole is obtained based on the target design displacement and geometric relationship.

[0004] Further, the pre-tightening force and number of the pre-tightening force control device are controlled by the design initial swing bending moment, and the pre-tightening force control device is a high-strength bolt + spring. The design initial swing bending moment includes the friction bending moment provided by the friction connection and the recovery bending moment provided by the self-weight of the structure, and the force arm of the recovery bending moment and the friction bending moment is the shortest distance from the center of the stiffening rib to the swing point of the stiffening rib flange.

[0005] Further, the column foot and the base are symmetrically or asymmetrically connected by friction.

[0006] Further, the high-strength bolt + spring is used as a pre-tightening force control device to directly apply axial tension to the node, and the pre-tightening force is controlled in stages by accurately adjusting the bolt fastening torque through a torque wrench according to the design initial swing bending moment theoretical value.

[0007] Further, the stepped friction surface of the tower cylinder stiffening rib and the friction outer cover plate is plated with a layer of polyethylene coating friction material.

[0008] Further, the stepped friction surface of the tower cylinder stiffening rib and the friction outer cover plate is made of high-hardness steel, brass, corundum, NAO, powder metal, semi-metal or carbon fiber material, etc.

[0009] A wind power tower cylinder seismic structure, which comprises eight wind power tower cylinder damping self-resetting friction column foot nodes.

[0010] Further, the wind power tower cylinder seismic structure connects the tower cylinder column segment and the steel bottom plate foundation through the column foot node, and ensures fixed connection under small earthquakes and can be lifted under large earthquakes, thereby realizing low damage under large earthquakes.

[0011] Compared with the prior art, the beneficial effects of the present application mainly lie in: 1. The wind power tower cylinder seismic structure focuses on the wind power tower cylinder column foot, and the force transmission path disperses the load through the ring stiffening rib + stepped friction plate surface contact energy dissipation, and the damping effect is derived from the cooperative working mechanism of friction energy dissipation and rocking seismic isolation. By setting the friction node at the column foot, the structure can continuously dissipate energy through the relative sliding of the interface under the action of earthquakes, and can effectively block part of the seismic input by lifting and rocking, thereby forming a double seismic defense line.

[0012] 2. The core mechanism of the wind power tower cylinder seismic structure is to release the seismic internal force through the rocking stepped friction surface, and the gravitational moment generated by the self-weight of the structure is used as the restoring force, thereby realizing efficient self-resetting. This mechanism significantly weakens the accumulation of seismic excitation in the structure, so that the tower cylinder can basically recover to the initial shape after the earthquake, effectively overcoming the inherent defect of large residual deformation of traditional rigidly connected structures, from the general "rectangular cross section, rigid connection" to "circular cross section, flexible coordination".

[0013] 3. By introducing the controllable rocking mechanism, the cooperation mode of the long hole slot (stiffening rib) + standard bolt hole, the unique design of the installation precision and the flexibility of the pre-tightening force control, the wind power tower cylinder seismic structure realizes internal force redistribution in the earthquake, thereby controlling the damage of the key components at a low level. The superiority of the design lies in the predictability and controllability of the damage mechanism, and the post-earthquake maintenance work is simplified to the inspection and resetting of the pre-tightening force applying device, that is, the structure function can be restored by re-tightening the device to the design pre-tightening force value.

[0014] 4、The wind power tower cylinder anti-seismic structure relates to the core components of ordinary steel (stiffening ribs, friction outer cover plates) and standard fasteners (bolts, pre-tightening devices), and the material procurement cost can be reduced by more than 40%; the long hole grooves of the stiffening ribs and the standard bolt holes of the friction outer cover plates can be completed through conventional punching processes, without complex groove processing, and the single-piece processing cost is reduced by 25%-30%.

[0015] 5、The wind power tower cylinder anti-seismic structure relates to the core components (stiffening ribs, friction outer cover plates, pre-tightening force control devices), which are all factory-standardized prefabricated, the stiffening ribs are independently distributed ring-shaped components, which can be welded in advance with the wind power tower cylinder column foot (completed in the factory prefabrication stage), avoiding on-site welding operation; the stiffening ribs and the friction outer cover plates are quickly connected through "standard bolt holes + pre-tightening force control devices", without step-by-step pre-tightening; the connection between the steel bottom plate foundation and the ground only needs conventional bolt fixing, without reserving complex grooves; the single-column foot installation time can be shortened by more than 30%, which is especially suitable for the harsh environment of wind power projects in the wild and high altitude. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 It is a structural schematic diagram of the symmetrical damping self-resetting wind power tower cylinder friction column foot node in the application.

[0017] Figure 2 It is an enlarged view of the symmetrical damping self-resetting wind power tower cylinder friction column foot node in the application.

[0018] Figure 3 It is a schematic diagram of the opening of the stiffening rib and the friction outer cover plate (the stiffening rib is taken as an example of a long hole groove).

[0019] Figure 4 It is a schematic diagram of the welding of the stiffening rib and the tower cylinder in the application.

[0020] Figure 5 It is a schematic diagram of the welding of the stiffening rib and the base in the application.

[0021] Among them, 100 is a self-resetting friction column foot node; 1 is a wind power tower cylinder; 2 is a stiffening rib; 3 is a friction outer cover plate; 4 is a pre-tightening force control device; 5 is a steel bottom plate foundation; 6 is a long hole groove; 7 is a standard bolt hole. DETAILED DESCRIPTION

[0022] The damping self-resetting wind power tower cylinder friction column foot node in the application will be described in more detail below in conjunction with the schematic diagram, wherein the preferred embodiment of the application is represented, it should be understood that the person skilled in the art can modify the application described herein while still achieving the advantageous effects of the application, therefore, the following description should be understood as extensive knowledge for the person skilled in the art, and not as a limitation of the application.

[0023] In the description of the present application, it needs to be particularly pointed out that the terms representing the orientation or position relationship mentioned in the text, such as "up", "down", "left", "right", "front", "back" and the like, are based on the structure of the present application shown in the drawings, and the use of these terms is only for the convenience of clear and concise description of the present application, and by no means is intended to limit the actual orientation, structure and operation mode of the device or element referred to. Therefore, these orientation terms should not be understood as limiting the present application, and those skilled in the art can make corresponding adjustments and changes to the orientation and position relationship of the related devices or elements based on the specific actual situation without departing from the core principle of the present application.

[0024] In the description of the present application, unless specifically limited or specially stated, the terms such as "mounting", "connection" should be understood in a broad sense. For example, "connection" can be fixed connection, or detachable connection, or one-piece connection; can be mechanical connection, or electrical connection; can be direct connection of two components or structures, or indirect connection through intermediate medium, or internal communication of two structures. Those skilled in the art should understand that the specific meaning of the above terms in the present application is not limited to a certain specific form, but according to the general idea of the present application, in combination with the specific context, different implementation modes can be possible in different situations, and the skilled person can flexibly grasp according to the actual situation, as long as the corresponding functions and purposes can be achieved, which are within the scope of the present application.

[0025] As shown in Figure 1 A damping wind turbine tower friction column foot node 100, including stiffener 2, friction cover plate 3, pre-tightening force control device 4, steel bottom plate foundation 5. Among them, each damping self-resetting wind turbine tower friction column foot node is connected in a symmetrical or asymmetrical manner.

[0026] Eight stiffeners 2 are fixed in turn at equal intervals on the wind turbine tower column foot, the column foot is placed on the steel bottom plate foundation 5, the steel bottom plate foundation 5 is connected to the ground by bolts, and the stiffeners 2 and the friction cover plate 3 are fixed in turn on both sides of the column foot stiffener through the pre-tightening force control device 4; the friction cover plate 3 has standard bolt holes 7, and the stiffener 2 has a large circular hole 6.

[0027] Specifically, as shown in Figure 4 The size of the large circular hole 6 should be designed according to the following design method: under the action of earthquake, the wind turbine tower begins to sway, the cylinder body swings along the flange of the column foot, the stiffener of the column foot moves vertically, and the energy is dissipated through friction, forming a rocking structure. When the structure reaches the maximum design displacement angle, the size of the stiffener large circular hole is calculated according to the target design displacement and the geometric relationship.

[0028] It can be understood that, as shown in Figure 1 Eight stiffening ribs 2 are welded on the upper part of the wind tower, continuous fillet welding is adopted, the inner and outer sides of the stiffening ribs 2 are attached to the inner friction plates 2, the outer side of the inner friction plates is attached to the friction outer cover plates 3, and the friction pairs are formed together. The stepped friction surfaces of the stiffening ribs 2, the inner friction plates 2 and the friction outer cover plates 3 are plated with a layer of polyethylene coating friction material, and the stepped friction surfaces of the eight inner friction plates 2 and the eight friction outer cover plates 3 are respectively tightly attached to the inner and outer sides of the sixteen stiffening ribs 2.

[0029] It can be understood that, as shown in Figure 5 Eight stiffening ribs 2 are welded on the steel base plate foundation 5, continuous fillet welding is adopted, the stiffening ribs 2 are clamped as the central friction plate on the inner side of the friction outer cover plates 3, and the stiffening ribs 2 and the friction outer cover plates 3 are stacked into a three-layer structure, so that the reliable sliding self-resetting mechanism is realized.

[0030] It can be understood that, as shown in Figure 2 The pre-tightening force control device 4 is composed of high-strength bolts + springs. The pre-tightening force is applied by the following ways: directly applying the axial tension of the bolt, according to the designed initial swing bending moment theoretical value, the torque wrench is used to accurately control the bolt fastening torque or the displacement control device is used to adjust the compression stroke of the elastic element, so that the step-by-step control of the pre-tightening force can be realized. It should be particularly pointed out that the self-resetting function of the structure is mainly derived from the stepped friction plate + pre-tightening force control device.

[0031] Referring to Figure 1 The nodes of the damping self-resetting wind tower friction column foot joint 100 all adopt the friction node as shown in Figure 2 Before the structure swings, all the column foot nodes are treated as fixed connection, and the design initial swing bending moment of the structure is calculated according to the small earthquake fixed connection calculation.

[0032] The above is only the preferred embodiment of the present application, and does not limit the present application in any way. Any person skilled in the art can make any form of equivalent replacement, modification or change to the technical solutions and technical contents disclosed by the present application without departing from the scope of the technical solutions of the present application, which still belongs to the protection scope of the present application.

Claims

1. A shock-absorbing self-resetting wind turbine tower friction column base joint, comprising: The wind turbine tower (2), stiffening rib (2), friction outer cover plate (3), pre-tightening force control device (4), and steel base plate foundation (5) are characterized in that the inner side of the stiffening rib (2) is fixedly connected to the column foot of the wind turbine tower, the inner side of the friction outer cover plate (3) is attached to both sides of the stiffening rib (2), and is connected by the pre-tightening force control device (4) that provides pre-tightening force, and the pre-tightening force control device (4), the friction outer cover plate (3), and the inner and outer sides of the stiffening rib (2) together constitute a friction pair; The friction outer cover plate (3) is provided with standard bolt holes, and the stiffening rib (2) is provided with vertical long slot holes or large round holes. The dimensions of the standard bolt holes and large round holes are obtained based on the target design displacement and geometric relationship.

2. The shock-absorbing self-resetting wind turbine tower friction column base node according to claim 1, characterized in that, The preload and quantity of the preload control device are controlled by the designed swing moment. The preload control device (4) is a high-strength bolt + spring. The design swing moment includes the friction moment provided by the friction connection and the recovery moment provided by the structure's own weight. The lever arm of both the recovery moment and the friction moment is the shortest distance from the center of the stiffener to the swing point of the stiffener flange.

3. The shock-absorbing self-resetting wind turbine tower friction column base node according to claim 1, characterized in that, The friction column base nodes of the vibration-damping self-resetting wind turbine tower are connected by friction in a symmetrical or asymmetrical manner.

4. The shock-absorbing self-resetting wind turbine tower friction column base node according to claim 3, characterized in that, High-strength bolts are used as preload control devices (4) to directly apply axial tension to the nodes. Based on the theoretical value of the design swing moment, the bolt tightening torque is precisely adjusted by a torque wrench to achieve graded control of the preload.

5. The shock-absorbing self-resetting wind turbine tower friction column base node according to claim 1, characterized in that, The inner side of the friction outer cover plate (3) and the stepped friction surfaces on both sides of the stiffening rib (2) are coated with a layer of polyethylene coating friction material.

6. The shock-absorbing self-resetting wind turbine tower friction column base node according to claim 1, characterized in that, The friction outer cover plate (3) and stiffening ribs (2) are made of wear-resistant materials such as high-hardness steel, corundum, brass, NAO, powder metal, semi-metal or carbon fiber.

7. A seismic-resistant structure for wind turbine towers, characterized in that: All nodes in the seismic-resistant structure of the wind turbine tower adopt the self-resetting friction column foot node of the wind turbine tower as described in any one of claims 1-6.

8. The seismic-resistant structure of the wind turbine tower according to claim 7, characterized in that: The earthquake-resistant structure of the wind turbine tower is designed to swing after a frequent earthquake as specified in my country's earthquake-resistant code, and to limit its movement under rare earthquakes. Before the wind turbine tower's seismic-resistant structure begins to swing, all column base nodes are treated as fixed connections. The design swing moment of the wind turbine tower's vibration-damping structure is calculated based on the fixed connections during minor earthquakes.

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