Variable-stiffness shock insulation structure system and method for strut equipment

Abstract

The invention relates to a variable-stiffness shock insulation structure system and method for strut equipment, the system is installed in a supporting structure below the strut equipment, the system comprises inclined rods, variable-stiffness shock insulation energy consumption connecting sets and self-resetting ribs, the inclined rods arranged in a crossed mode and the self-resetting ribs arranged in a staggered mode are arranged in column limbs of a lattice type tower of the supporting structure, and the inclined rods are connected with the self-resetting ribs. A sliding groove is formed in the column limb in the vertical direction, the pair of inclined rods is hinged to the middle point, the lower ends of the inclined rods are hinged to the column limb, and the upper ends of the inclined rods are connected with the sliding groove in a sliding mode through a variable-rigidity shock insulation energy dissipation connecting set. The variable-stiffness shock insulation energy dissipation connecting set comprises a spring set and a viscous damper, and the upper end of the inclined rod is connected with the lower side surface and the two side surfaces of the sliding groove through the spring set and connected with the upper side surface of the sliding groove through the viscous damper. Compared with the prior art, three-dimensional synergistic shock insulation and nonlinear synergistic energy consumption are achieved on a large-range frequency band, and the deformation limiting function under large deformation and the static bearing requirement under small deformation are met.

Description

Technical Field

[0001] The invention belongs to the technical field of civil engineering, and relates to a variable stiffness seismic isolation structure system and method for pillar-type equipment. Background Art

[0002] There are two main assembly forms for the existing three-dimensional seismic isolation bearings of transformer substation pillar equipment.

[0003] A type of three-dimensional seismic isolation bearing is installed at the bottom of the supporting structure. Although this type of three-dimensional seismic isolation bearing can reduce the structural stress response, it is not conducive to controlling the displacement of the top of the slender pillar-type equipment under bending deformation, and it is easy to cause high-frequency vibration and uneven force at the connection between the pillar-type equipment and the support. How to use the vertical bending deformation of the pillar-type equipment for vibration isolation and broaden the isolation frequency band needs further exploration. In addition, in the existing seismic isolation structure, parameters such as springs and damping are basically fixed and cannot be dynamically adjusted according to changes in external excitation.

[0004] Another type of three-dimensional seismic isolation bearing is installed between the pillar-type equipment and the supporting structure, forming a series structural system. In view of the limitations of the connection space, the size of this type of three-dimensional seismic isolation bearing needs to be strictly controlled to avoid unnecessary increase in the overall height of the structure. Therefore, while this type of three-dimensional seismic isolation bearing has the three-dimensional seismic isolation function, its vertical bearing capacity is seriously insufficient, and there is an inherent contradiction between the deformation energy dissipation capacity and the seismic isolation effect and seismic isolation deformation control. How to achieve variable nonlinear adaptive adjustment of the vertical stiffness of the system, while satisfying the deformation limiting capacity of the system under large deformation, while ensuring the static load capacity under small deformation, still needs further exploration. In addition, the energy consumption efficiency of the existing three-dimensional seismic isolation bearings under dynamic response is not high, and it is necessary to further reduce the stress concentration and displacement response of the seismic isolation system.

[0005] Patent CN107989226A discloses a combined system of energy-absorbing connecting beams and viscous dampers and a design method thereof. The combined system consists of multiple energy-absorbing connecting beams and multiple viscous dampers. The multiple energy-absorbing connecting beams are arranged side by side between two adjacent wall limbs. The multiple energy-absorbing connecting beams separate the two adjacent wall limbs into multiple openings, and at least one viscous damper is arranged in each opening. The patent emphasizes the improvement of the stiffness and damping of the shear wall structure by the combined system, but does not consider the stress concentration problem at the connection between the wall limb and the energy-absorbing connecting beam and the viscous damper, and cannot solve the shortcomings in the overall stability of the structure (such as anti-overturning stability and anti-torsion stability).

[0006] Patent CN118934901A discloses a stretcher vibration isolation system integrating quasi-zero stiffness and controllable damping and a control method thereof. The system includes a quasi-zero stiffness vibration isolator, an electromagnetic controllable damper and a stretcher body; the quasi-zero stiffness vibration isolator is composed of a vertical spring, a horizontally placed negative stiffness mechanism (composed of a negative stiffness structural sleeve, an oblique spring, and a negative stiffness structural push rod) and a quasi-zero stiffness vibration isolator base, etc.; wherein the vertical spring is installed on a protective shell of the electromagnetic controllable damper and is in a parallel installation form with the electromagnetic controllable damper, the protective shell of the electromagnetic controllable damper plays a guiding role to avoid the vertical spring from being unbalanced during the stretching and compression process, the vertical spring is mainly used to bear the load and play a supporting role to avoid a large static displacement of the stretcher; the negative stiffness structural sleeve and the negative stiffness structural push rod in the negative stiffness structure mainly play a guiding role to avoid the oblique spring from being unbalanced during the stretching and compression process, and the negative stiffness structural sleeve is connected to a vertical support frame fixed on the base. However, the parallel connection technology of quasi-zero stiffness unit and variable damping unit proposed in the patent is only applicable to the vibration isolation problem of small load and large deformation of bracket-type equipment. It still cannot solve the contradiction between static bearing capacity and high-performance vibration isolation of pillar-type equipment under large load and small deformation conditions, and it cannot solve the problem of controlling bending deformation of tall pillar-type structures.

[0007] Patent CN109763581A discloses a building structure foundation module with three-dimensional seismic isolation and vibration reduction, which mainly includes: a small steel structure platform, a sliding support, a laminated special rubber / steel plate support with a variable vertical stiffness combination and vertical self-adjusting deformation ability, and a centrally connected viscoelastic damping energy absorbing shock absorber; the main piston of the viscoelastic energy dissipation damping shock absorber adopts a micro-porous metal fiber felt or a laminated stainless steel fiber woven mesh composition with an internal friction energy absorption mechanism as a damping element, and adopts medium-viscosity silicone oil as a damping medium, and a metal disc spring element After being stacked and combined, the components are placed inside and below the outer cylinder of the shock absorber, playing the main vertical support role and elastic recovery function for the lower pressure head of the piston rod cylinder. The main piston is fixedly connected to the inside of the piston rod cylinder. A first return spring is arranged between the upper part of the main piston and the lower part of the floating piston. A second return spring is arranged between the upper part of the floating piston and the end cover of the upper end of the piston rod cylinder, and a part of the gas space is maintained without liquid damping medium. The liquid damping medium filled below the floating piston adopts dimethyl silicone oil with medium and high viscosity. However, the technical solution of setting the viscoelastic damping energy absorbing shock absorber in parallel with the center of the support in this patent can only achieve the vertical linear vibration isolation of the structure, which is not suitable for the bending deformation control of the pillar-type high-rise equipment under the action of earthquake, and cannot solve the deformation control problem of the vibration isolation layer under the premise of low dynamic stiffness. In addition, the oil-containing self-lubricating liquid-solid two-phase material used in this patent has high temperature sensitivity and is not suitable for the complex climatic conditions where pillar-type power equipment is located. The changes in its material properties and sliding friction coefficient will significantly weaken the vibration isolation effect. Summary of the invention

[0008] The purpose of the present invention is to provide a variable stiffness seismic isolation structure system and method for pillar-type equipment in order to overcome at least one defect of the above-mentioned prior art. The present invention realizes three-dimensional enhanced seismic isolation and nonlinear enhanced energy consumption over a wide frequency band, meeting the deformation limiting function under large deformation and the static bearing requirements under small deformation.

[0009] The purpose of the present invention can be achieved by the following technical solutions:

[0010] One of the technical solutions of the present invention is to provide a variable stiffness seismic isolation structure system for pillar-type equipment, which is installed in the supporting structure under the pillar-type equipment, and the system includes diagonal rods, a variable stiffness seismic isolation energy dissipation connection group and self-resetting ribs. The cross-arranged diagonal rods and the staggered self-resetting ribs are arranged in the column limbs of the lattice tower of the supporting structure, and a slide groove is provided in the column limb in the vertical direction. A pair of diagonal rods are hinged at the midpoint, and the lower end of the diagonal rod is hinged to the column limb, and the upper end is slidably connected to the slide groove through the variable stiffness seismic isolation energy dissipation connection group to form a cross-type hinge mechanism with nonlinear stiffness. When the column limb is hinged to the lower base of the pillar-type equipment, the column limb is allowed to rotate around the upper end, so that the diagonal rod can rotate around the lower end of the diagonal rod in the plane where the cross-type hinge mechanism with nonlinear stiffness is located, thereby allowing relative movement between the column limbs;

[0011] The variable stiffness seismic isolation and energy dissipation connection group includes a spring group and a viscous damper. The upper end of the inclined rod is connected to the lower surface and the two side surfaces of the slide slot through the spring group, and is connected to the upper surface of the slide slot through the viscous damper. The variable stiffness seismic isolation and energy dissipation connection group equivalently provides variable negative stiffness that increases with displacement, while satisfying the deformation limiting function under large deformation and the static bearing capacity under small deformation.

[0012] Under the action of an earthquake, the column limbs tend to approach each other along the vibration direction, driving the upper end of the diagonal rod to move in the slide groove. The self-resetting ribs are used to force the column limbs to return to a static state. After the vibration ends, the column limbs return to their initial static state along the control path under the action of the self-resetting ribs.

[0013] As a preferred technical solution, the form of the column limb is selected from one or more of a square cross-section column, a circular cross-section column, and an H-shaped cross-section column, and the material is selected from one or more of steel, concrete, and a composite material.

[0014] As a preferred technical solution, the gravity of the equipment under static load is mainly borne by the columns of the lattice tower. By increasing the cross-sectional area of ​​the columns, the overall vertical bearing capacity of the tower can be improved, while its bending, torsional resistance and stability are also enhanced.

[0015] As a preferred technical solution, the self-resetting ribs are prestressed steel bars, so that the self-resetting ribs provide a restoring control force when they are stretched during structural deformation, so that the self-resetting ribs can restore their original length while restoring the structure to its initial state.

[0016] As a preferred technical solution, several slide grooves are evenly distributed in the vertical direction, several pairs of cross-arranged oblique rods are evenly distributed in the vertical direction, and several pairs of staggered self-resetting ribs are evenly distributed in the vertical direction.

[0017] As a preferred technical solution, the upper end of the oblique rod is connected to the upper surface of the slide groove through at least one viscous damper.

[0018] Furthermore, the diagonal rod is connected to two adjacent column limbs, the self-resetting rib is fixedly connected to two adjacent column limbs, the cross-arranged diagonal rods and the staggered arranged self-resetting ribs are in different vertical planes, and under the action of static force, the lower ends of the diagonal rods and the self-resetting ribs in the same horizontal plane are at the same height, and the upper ends are at the same height.

[0019] As a preferred technical solution, the staggered self-resetting ribs are distributed on the inner side of the cross-arranged oblique rods.

[0020] Furthermore, the spring group includes a vertical spring and a horizontal spring. The lower side of the upper end of the inclined rod is connected to the lower surface of the slide slot through the vertical spring, and the two sides are connected to the two side surfaces of the slide slot through horizontal springs. The horizontal spring is pre-stressed. The pre-stressed horizontal spring generates a force in the opposite direction to the elastic force of the vertical spring during vibration, thereby reducing the linear part of the equivalent restoring force. The pre-stressed horizontal spring reduces the linear stiffness coefficient of the cross-type hinge mechanism with nonlinear stiffness and increases the nonlinear stiffness coefficient, thereby improving the static bearing capacity of the variable stiffness seismic isolation structure system. Under the action of static force, the cross-type hinge mechanism with nonlinear stiffness exhibits smaller deformation than the linear seismic isolation structure, which is attributed to the reduction of its linear stiffness, even close to zero, thereby significantly reducing the natural frequency of the system. This low natural frequency enables the cross-type hinge mechanism with nonlinear stiffness to achieve effective seismic isolation effect within a wider frequency range.

[0021] As a preferred technical solution, the lower side of the upper end of the inclined rod is connected to the lower surface of the slide slot through at least one vertical spring, and the two sides are connected to the two side surfaces of the slide slot through at least one pair of horizontal springs.

[0022] As a preferred technical solution, the two ends of the vertical spring are respectively vertically fixedly connected to the lower side of the upper end of the inclined rod and the lower surface of the slide groove, and the two ends of the horizontal spring are respectively horizontally fixedly connected to the side surface of the upper end of the inclined rod and the side surface of the slide groove.

[0023] As a preferred technical solution, by adjusting the geometric dimensions and stiffness characteristics of the horizontal spring, the stiffness characteristics of the system can be further adjusted to achieve ultra-low frequency vibration isolation to meet different engineering requirements.

[0024] As a preferred technical solution, both ends of the viscous damper are vertically connected to the upper side of the upper end of the inclined rod and the upper surface of the slide groove through cables.

[0025] As a preferred technical solution, the upper and lower ends of the viscous damper are respectively provided with ear plates, one end of the cable at the lower end of the viscous damper passes through the ear plate at the lower end, and the other end is vertically fixedly connected to the upper side of the upper end of the inclined rod, and one end of the cable at the upper end passes through the ear plate at the upper end, and the other end is vertically fixedly connected to the upper surface of the slide groove.

[0026] Furthermore, the outer surface of the slide groove is semi-closed, and a slide rail is arranged on the outer surface of the slide groove. The inclined rod passes through the outer surface of the slide groove. The upper end of the inclined rod and the variable stiffness seismic isolation and energy absorption connection group are arranged in the slide groove. The inclined rod slides under the control of the guide action of the slide rail, and the slide rail ensures the planar stability of the cross-type hinge mechanism with nonlinear stiffness when the upper end of the inclined rod moves vertically.

[0027] Furthermore, a sphere is disposed at the upper end of the oblique rod in the slide groove, the diameter of the sphere being larger than the spacing of the slide rails, and the sphere contacts the slide rails to ensure that the upper end of the oblique rod will not escape from the slide groove.

[0028] Furthermore, a friction inner plate is provided on the inner surface of the slide groove, the ball at the upper end of the inclined rod is in contact with the friction inner plate, the diameter of the ball at the upper end of the inclined rod is adapted to the depth of the slide groove on which the friction inner plate is installed, and the friction inner plate can slide relative to the ball at the upper end of the inclined rod to generate friction.

[0029] Furthermore, the material of the friction inner plate is selected from one or more of rubber, brass, and wollastonite with a high friction coefficient. The purpose of this design is to ensure that when the ball at the upper end of the inclined rod moves along the slide rail, sufficient friction can be generated between the ball and the friction inner plate, thereby promoting energy dissipation of the system.

[0030] Furthermore, the viscous damper includes a connector, a piston, a cylinder body and a damping medium. The upper end of the viscous damper is connected to the connector, and the connector extends into the cylinder body. A fluid channel is arranged between the connector and the cylinder body, and the fluid channel is filled with damping medium. A piston is arranged on the part of the connector extending into the fluid channel, and a small hole or a gap is opened on the piston. When the system vibrates, the upper end of the viscous damper acts on the piston in the viscous damper through the connector, so that the piston moves relatively in the cylinder body. This movement prompts the damping medium to flow through the small hole or gap on the piston. In this process, the damping medium undergoes shearing and generates viscous resistance in the fluid channel. This resistance converts the kinetic energy of the fluid into heat energy, thereby realizing energy dissipation.

[0031] As a preferred technical solution, the ear plate at the upper end of the viscous damper is fixedly connected to the connector, and the ear plate at the lower end is fixedly connected to the cylinder body.

[0032] Furthermore, the material of the damping medium is selected from one or more of dimethyl silicone oil, polyurethane, and acrylic acid.

[0033] As a preferred technical solution, the damping characteristics of the viscous damper can be precisely adjusted by changing the size and shape of the fluid channel and selecting damping media with different viscosities.

[0034] One of the technical solutions of the present invention is to provide a variable stiffness seismic isolation method for pillar-type equipment, which uses the system to perform variable stiffness seismic isolation for pillar-type equipment in a substation, and the method comprises the following steps:

[0035] When the system is in a vibrating state, the hinged characteristics of the diagonal rod cause the horizontal distance between the column members to shorten under the vertical bending deformation, thereby driving the upper end of the diagonal rod to move along the slide rail. The variable stiffness isolation energy dissipation connection group then provides an equivalent variable negative stiffness that increases with displacement, reducing the natural frequency of the structure. The vertically assembled variable stiffness isolation energy dissipation connection group can also play a role in vertical isolation, realizing three-dimensional enhanced isolation and nonlinear enhanced energy dissipation over a wide frequency band, meeting the deformation limit function under large deformation and the static bearing requirements under small deformation.

[0036] At the same time, the relative sliding between the upper end of the inclined rod and the friction inner plate enhances the energy consumption of the system and improves the seismic isolation efficiency;

[0037] The self-resetting ribs provide self-resetting control force for the deformed pillar-type structure, so that the structure can be restored to its initial static state, reducing or even eliminating the residual deformation of the structure;

[0038] Under static load, the vertical spring provides stable support and shares part of the vertical bearing force acting on the upper end of the diagonal rod, maintaining the vertical balance of the structure, while the horizontal spring is in a pre-stressed state, keeping it compact and ready. Under vibration, the upper end of the diagonal rod will move in the direction of the slide rail, driving the vertical spring to deform. At this time, the vertical spring continues to bear the vertical load and adapt to the displacement, while the horizontal spring deforms through the negative stiffness effect, reducing vibration transmission, and the viscous damper realizes energy dissipation.

[0039] Compared with the prior art, the present invention has the following beneficial effects:

[0040] (1) The present invention proposes a seismic isolation structure system for pillar-type equipment of a substation, which includes a unidirectional prestressed variable stiffness spring group structure, which significantly prolongs the natural vibration period of the pillar-type equipment of the substation, and realizes the variable nonlinear adaptive adjustment of the vertical linear and bending stiffness of the seismic isolation structure system; this design utilizes the vertical bending deformation of the pillar-type equipment for vibration isolation, and can equivalently provide a variable negative stiffness that increases with displacement, so that the seismic isolation structure system exhibits excellent low-frequency seismic isolation performance and deformation limiting function under large deformation, and can effectively reduce the structural response of the pillar-type equipment caused by ground motion during an earthquake;

[0041] (2) While maintaining the high stability and static bearing capacity of the pillar-type equipment under small deformation, the present invention can further improve the vertical bearing capacity of the support system for the pillar-type equipment by adjusting the column limb size of the original lattice tower; the self-resetting ribs inside the seismic isolation structure system of the substation pillar-type equipment are arranged between the column limbs in a cross-type layout and staggered with the hinge mechanism to ensure the static bearing state of the column limbs of the seismic isolation structure system of the substation pillar-type equipment and ensure the adaptive self-resetting capacity of the seismic isolation system of the substation pillar-type structure;

[0042] (3) The present invention adopts a cross-shaped hinge mechanism with nonlinear stiffness formed by hinged inclined rods to transfer the force caused by vibration to the variable stiffness spring group and the viscous damper to achieve a three-dimensional seismic isolation effect; through the sliding friction between the cross-shaped hinge mechanism with nonlinear stiffness and the friction inner plate and the effect of the viscous damper, the system achieves a good energy dissipation effect;

[0043] (4) In traditional seismic isolation systems, the fixed nature of parameters such as springs and damping limits their adaptability to changes in external excitations, making it impossible to achieve optimal design of the structure. Specifically, high-stiffness configurations reduce the isolation frequency band, while low-stiffness configurations weaken the bearing capacity of the structure. At the same time, although damping can suppress vibrations in the non-isolation frequency band, it reduces the isolation efficiency in the isolation frequency band. These factors together lead to challenges in traditional seismic isolation technology in resolving the contradiction between performance requirements. However, the application of nonlinear stiffness and damping characteristics in static seismic isolation devices can significantly enhance the stability and static bearing capacity of the device and optimize the vibration isolation effect in the high-frequency range. In view of this, the present invention proposes a variable stiffness seismic isolation system with a nonlinear stiffness mechanism. The system adopts a vertical spring and a pre-stressed horizontal spring in parallel configuration, and by adjusting the geometric dimensions and stiffness characteristics of the spring, the goal of reducing the natural frequency of the substation pillar equipment is achieved; in addition, under the action of three-dimensional earthquakes, the substation pillar equipment can maintain large deformation limiting capacity and static load capacity under small deformation; further, based on the variable stiffness isolation energy dissipation connection group of the present invention, not only the isolation frequency band is broadened, but also the stability of the pillar equipment is improved, and the effective dissipation of energy is achieved; the present invention establishes an enhanced isolation energy dissipation path based on the negative stiffness unit-viscous damper and a static load bearing and self-resetting path based on self-resetting ribs, which can effectively provide a three-dimensional isolation frequency band that meets the substation pillar equipment including the bending deformation degree of freedom. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 It is a structural schematic diagram of a variable stiffness seismic isolation structure system of pillar-type equipment in an embodiment of the present invention installed in a supporting structure under the pillar-type equipment of a substation;

[0045] Figure 2 It is a schematic diagram of the bearing capacity state of the variable stiffness seismic isolation structure system of the pillar type equipment under the action of static load in the embodiment of the present invention;

[0046] Figure 3 It is a schematic diagram of the deformation state of the variable stiffness seismic isolation structure system of the pillar type equipment in the embodiment of the present invention under the action of a horizontal earthquake;

[0047] Figure 4 It is a schematic diagram of the state of the variable stiffness seismic isolation energy dissipation connection group under the action of static load in an embodiment of the present invention;

[0048] Figure 5 It is a schematic diagram of the state of the variable stiffness seismic isolation energy dissipation connection group under the action of a horizontal earthquake in an embodiment of the present invention;

[0049] Figure 6 Schematic diagram of the structure of the viscous damper in an embodiment of the present invention.

[0050] Description of the markings in the figure:

[0051] 1—column limb, 2—diagonal rod, 3—variable stiffness seismic isolation energy absorption connection group, 4—self-resetting rib, 5—friction inner plate, 6—slide rail, 8—viscous damper, 9—vertical spring, 10—horizontal spring, 11—connector, 12—piston, 13—cylinder body, 14—damping medium. DETAILED DESCRIPTION

[0052] The present invention is described in detail below in conjunction with specific embodiments. This embodiment is implemented based on the technical solution of the present invention, and provides a detailed implementation method and a specific operation process, but the protection scope of the present invention is not limited to the following embodiments.

[0053] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inside", "outside", etc. indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, which are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply 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 a limitation on the present invention. In addition, the terms "first", "second", "third", etc. are used to describe common objects, which only refer to different instances of the same object, and are not intended to imply that the objects described in this way must adopt a given order, whether in time, space, order or any other way.

[0054] 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.

[0055] Example:

[0056] A variable stiffness seismic isolation structure system for pillar-type equipment, such as Figures 1 to 3As shown, it is installed in the supporting structure under the pillar-type equipment, including the inclined rod 2, the variable stiffness seismic isolation energy dissipation connection group 3 and the self-resetting rib 4. The cross-arranged inclined rods 2 and the staggered self-resetting ribs 4 are arranged in the column limb 1 of the lattice tower of the supporting structure. A slide groove is opened in the column limb 1 in the vertical direction. A pair of inclined rods 2 are hinged at the midpoint. The lower end of the inclined rod 2 is hinged to the column limb 1, and the upper end is slidably connected to the slide groove through the variable stiffness seismic isolation energy dissipation connection group 3 to form a cross-type hinge mechanism with nonlinear stiffness. When the column limb 1 is hinged to the lower base of the pillar-type equipment, the column limb 1 is allowed to rotate around the upper end, so that the inclined rod 2 can rotate around the lower end of the inclined rod 2 in the plane where the cross-type hinge mechanism with nonlinear stiffness is located, thereby allowing relative movement between the column limbs 1;

[0057] Under the action of earthquake, the column limbs 1 tend to approach each other along the vibration direction, driving the upper end of the inclined rod 2 to move in the slide groove, and the self-resetting ribs 4 are used to force the column limbs 1 to restore the static state. After the vibration ends, the column limbs 1 are restored to the initial static state along the control path under the action of the self-resetting ribs 4;

[0058] The form of the column limb 1 is selected from one or more of a square cross-section column, a circular cross-section column, and an H-shaped cross-section column, and in this embodiment, a square cross-section column is preferred, and the material is selected from one or more of steel, concrete, and a composite material, and in this embodiment, steel is preferred;

[0059] Under static load, the equipment gravity is mainly borne by the column 1 of the lattice tower. By increasing the cross-sectional area of ​​the column 1, the overall vertical bearing capacity of the tower can be improved, while also enhancing its bending and torsional resistance and stability.

[0060] The self-resetting ribs 4 are prestressed steel bars, so that the self-resetting ribs 4 provide a restoring control force when they are stretched during structural deformation, so that the self-resetting ribs 4 can restore their original length and the structure can be restored to its initial state.

[0061] Several slide grooves are evenly distributed in the vertical direction, several pairs of cross-arranged oblique rods 2 are evenly distributed in the vertical direction, and several pairs of staggered self-resetting ribs 4 are evenly distributed in the vertical direction;

[0062] The oblique rods 2 are connected to two adjacent column limbs 1, and the self-resetting ribs 4 are fixedly connected to the two adjacent column limbs 1. The cross-arranged oblique rods 2 and the staggered self-resetting ribs 4 are in different vertical planes. Under the action of static force, the oblique rods 2 and the self-resetting ribs 4 in the same horizontal plane have the same height at the lower end and the same height at the upper end.

[0063] The staggered self-resetting ribs 4 are distributed on the inner side of the cross-arranged oblique rods 2;

[0064] like Figure 4 and Figure 5As shown, the variable stiffness seismic isolation energy dissipation connection group 3 includes a spring group and a viscous damper 8. The upper end of the inclined rod 2 is connected to the lower surface and both side surfaces of the slide slot through the spring group, and is connected to the upper surface of the slide slot through at least one viscous damper 8, which is preferably one in this embodiment. The variable stiffness seismic isolation energy dissipation connection group 3 equivalently provides a variable negative stiffness that increases with displacement, while satisfying the deformation limiting function under large deformation and the static bearing capacity under small deformation.

[0065] The spring group includes a vertical spring 9 and a horizontal spring 10. The lower side of the upper end of the inclined rod 2 is connected to the lower surface of the slide groove through at least one vertical spring 9, preferably one in this embodiment. The two sides are connected to the two side surfaces of the slide groove through at least one pair of horizontal springs 10, preferably two in this embodiment. The horizontal spring 10 is pre-stressed. The pre-stressed horizontal spring 10 generates a force in the opposite direction to the elastic force of the vertical spring 9 during vibration, reducing the linear part of the equivalent restoring force. The pre-stressed horizontal spring 10 reduces the linear stiffness coefficient of the cross-type hinge mechanism with nonlinear stiffness and increases the nonlinear stiffness coefficient, thereby improving the static bearing capacity of the variable stiffness seismic isolation structure system. Under the action of static force, the cross-type hinge mechanism with nonlinear stiffness shows smaller deformation than the linear seismic isolation structure, which is attributed to the reduction of its linear stiffness, even close to zero, thereby significantly reducing the natural frequency of the system. This low natural frequency enables the cross-type hinge mechanism with nonlinear stiffness to achieve effective seismic isolation effect in a wider frequency range.

[0066] The two ends of the vertical spring 9 are respectively vertically fixedly connected to the lower side of the upper end of the inclined rod 2 and the lower surface of the slide groove, and the two ends of the horizontal spring 10 are respectively horizontally fixedly connected to the side surface of the upper end of the inclined rod 2 and the side surface of the slide groove;

[0067] By adjusting the geometric dimensions and stiffness characteristics of the horizontal spring 10, the stiffness characteristics of the system can be further adjusted to achieve ultra-low frequency vibration isolation to meet different engineering requirements;

[0068] The two ends of the viscous damper 8 are vertically connected to the upper side of the upper end of the inclined rod 2 and the upper side surface of the slide groove through cables respectively;

[0069] The upper and lower ends of the viscous damper 8 are respectively provided with ear plates, one end of the cable at the lower end of the viscous damper 8 passes through the ear plate at the lower end, and the other end is vertically fixedly connected to the upper side of the upper end of the inclined rod 2, and one end of the cable at the upper end passes through the ear plate at the upper end, and the other end is vertically fixedly connected to the upper surface of the slide groove;

[0070] The outer surface of the slideway is semi-closed, and a slide rail 6 is arranged on the outer surface of the slideway. The inclined rod 2 passes through the outer surface of the slideway. The upper end of the inclined rod 2 and the variable stiffness seismic isolation energy dissipation connection group 3 are arranged in the slideway. The inclined rod 2 slides under the guidance of the slide rail 6. The slide rail 6 ensures the plane stability of the cross-type hinge mechanism with nonlinear stiffness when the upper end of the inclined rod 2 moves vertically.

[0071] A sphere is disposed at the upper end of the inclined rod 2 in the slide groove, the diameter of the sphere being larger than the spacing of the slide rails 6, and the sphere contacts the slide rails 6 to ensure that the upper end of the inclined rod 2 will not leave the slide groove;

[0072] A friction inner plate 5 is arranged on the inner surface of the slide groove, and the ball at the upper end of the inclined rod 2 contacts the friction inner plate 5. The diameter of the ball at the upper end of the inclined rod 2 is adapted to the depth of the slide groove where the friction inner plate 5 is installed. The friction inner plate 5 can slide relative to the ball at the upper end of the inclined rod 2 to generate friction.

[0073] The material of the friction inner plate 5 is selected from one or more of rubber, brass, and wollastonite with a high friction coefficient. In this embodiment, rubber is preferred. The purpose of this design is to ensure that when the ball at the upper end of the inclined rod 2 moves along the slide rail 6, sufficient friction can be generated between the ball and the friction inner plate 5, thereby promoting energy dissipation of the system.

[0074] like Figure 6 As shown, the viscous damper 8 includes a connector 11, a piston 12, a cylinder 13 and a damping medium 14. The upper end of the viscous damper 8 is connected to the connector 11, and the connector 11 extends into the cylinder 13. A fluid channel is provided between the connector 11 and the cylinder 13, and the fluid channel is filled with the damping medium 14. A piston 12 is provided on the portion of the connector 11 extending into the fluid channel, and a small hole or gap is provided on the piston 12. When the system vibrates, the upper end of the viscous damper 8 acts on the piston 12 in the viscous damper 8 through the connector 11, so that the piston 12 moves relatively in the cylinder 13. This movement causes the damping medium 14 to flow through the small hole or gap on the piston 12. In this process, the damping medium 14 undergoes shearing action and generates viscous resistance in the fluid channel. This resistance converts the kinetic energy of the fluid into heat energy to achieve energy dissipation.

[0075] The upper ear plate of the viscous damper 8 is fixedly connected to the connecting body 11, and the lower ear plate is fixedly connected to the cylinder body 13;

[0076] The material of the damping medium 14 is selected from one or more of dimethyl silicone oil, polyurethane, and acrylic acid, and in this embodiment, dimethyl silicone oil is preferred;

[0077] By changing the size and shape of the fluid channel and selecting damping media 14 with different viscosities, the damping characteristics of the viscous damper 8 can be precisely adjusted.

[0078] A variable stiffness seismic isolation method for pillar-type equipment, using the above system to perform variable stiffness seismic isolation of pillar-type equipment in a substation, and the specific steps are as follows:

[0079] When the system is in a vibrating state, the hinged characteristics of the diagonal rod 2 cause the horizontal distance between the column members 1 to shorten under vertical bending deformation, thereby driving the upper end of the diagonal rod 2 to move along the slide rail 6, and the variable stiffness isolation energy dissipation connection group 3 equivalently provides a variable negative stiffness that increases with displacement, thereby reducing the natural frequency of the structure. The vertically assembled variable stiffness isolation energy dissipation connection group 3 can also play a role in vertical isolation, realizing three-dimensional enhanced isolation and nonlinear enhanced energy dissipation over a wide frequency band, satisfying the deformation limit function under large deformation and the static bearing requirements under small deformation.

[0080] At the same time, the relative sliding between the upper end of the inclined rod 2 and the friction inner plate 5 enhances the energy consumption of the system and improves the seismic isolation efficiency;

[0081] The self-resetting ribs 4 provide a self-resetting control force for the deformed pillar-type structure, so that the structure can be restored to the initial static state, reducing or even eliminating the residual deformation of the structure;

[0082] Under static load, the vertical spring 9 provides stable support and shares part of the vertical bearing force acting on the upper end of the diagonal rod 2, maintaining the vertical balance of the structure, and the horizontal spring 10 is in a pre-stressed state, maintaining a compact and ready state; under vibration, the upper end of the diagonal rod 2 will move in the direction of the slide rail 6, driving the vertical spring 9 to deform. At this time, the vertical spring 9 continues to bear the vertical load and adapt to the displacement. The horizontal spring 10 is deformed through the negative stiffness effect, reducing vibration transmission, and the viscous damper 8 realizes energy dissipation.

[0083] The above description of the embodiments is to facilitate the understanding and use of the invention by those skilled in the art. It is obvious that those skilled in the art can easily make various modifications to these embodiments and apply the general principles described herein to other embodiments without creative work. Therefore, the present invention is not limited to the above embodiments, and improvements and modifications made by those skilled in the art based on the disclosure of the present invention without departing from the scope of the present invention should be within the scope of protection of the present invention.

Claims

1. A variable stiffness seismic isolation structure system for pillar-type equipment, characterized in that: The system is installed in a supporting structure under a pillar-type device, and comprises an inclined rod (2), a variable stiffness seismic isolation energy absorption connection group (3) and a self-resetting rib (4). The cross-arranged inclined rods (2) and the staggered self-resetting ribs (4) are arranged in a column limb (1) of a lattice tower of the supporting structure. A slide groove is provided in the column limb (1) in a vertical direction. A pair of inclined rods (2) are hinged at the midpoint. The lower end of the inclined rod (2) is hinged to the column limb (1), and the upper end is slidably connected to the slide groove through the variable stiffness seismic isolation energy absorption connection group (3). The variable stiffness seismic isolation energy dissipation connection group (3) comprises a spring group and a viscous damper (8); the upper end of the inclined rod (2) is connected to the lower surface and the two side surfaces of the slide groove through the spring group, and is connected to the upper surface of the slide groove through the viscous damper (8).

2. The variable stiffness seismic isolation structure system of pillar-type equipment according to claim 1 is characterized in that: The inclined rods (2) are connected to two adjacent column limbs (1), and the self-resetting ribs (4) are fixedly connected to two adjacent column limbs (1). The cross-arranged inclined rods (2) and the staggered arranged self-resetting ribs (4) are located in different vertical planes. Under the action of static force, the lower ends of the inclined rods (2) and the self-resetting ribs (4) in the same horizontal plane have the same height, and the upper ends have the same height.

3. The variable stiffness seismic isolation structure system of pillar-type equipment according to claim 1 is characterized in that: The spring group comprises a vertical spring (9) and a horizontal spring (10); the lower side of the upper end of the inclined rod (2) is connected to the lower surface of the slide groove via the vertical spring (9); the two sides are connected to the two side surfaces of the slide groove via the horizontal spring (10); and the horizontal spring (10) is pre-stressed.

4. The variable stiffness seismic isolation structure system of pillar-type equipment according to claim 1 is characterized in that: The outer surface of the slide groove is semi-closed, and a slide rail (6) is arranged on the outer surface of the slide groove. The inclined rod (2) passes through the outer surface of the slide groove. The upper end of the inclined rod (2) and the variable stiffness seismic isolation energy absorption connection group (3) are arranged in the slide groove, and the inclined rod (2) slides under the guidance of the slide rail (6).

5. The variable stiffness seismic isolation structure system of pillar-type equipment according to claim 4, characterized in that: A sphere is arranged at the upper end of the inclined rod (2) in the slide groove, the diameter of the sphere is greater than the spacing of the slide rails (6), and the sphere is in contact with the slide rails (6).

6. The variable stiffness seismic isolation structure system of pillar-type equipment according to claim 5, characterized in that: A friction inner plate (5) is provided on the inner surface of the slide groove, and the ball at the upper end of the inclined rod (2) is in contact with the friction inner plate (5).

7. The variable stiffness seismic isolation structure system of pillar-type equipment according to claim 6, characterized in that: The material of the friction inner plate (5) is selected from one or more of rubber, brass, and wollastonite.

8. The variable stiffness seismic isolation structure system for pillar-type equipment according to claim 1, characterized in that: The viscous damper (8) comprises a connecting body (11), a piston (12), a cylinder body (13) and a damping medium (14); the upper end of the viscous damper (8) is connected to the connecting body (11); the connecting body (11) extends into the cylinder body (13); a fluid channel is provided between the connecting body (11) and the cylinder body (13); the fluid channel is filled with the damping medium (14); a piston (12) is provided on the portion of the connecting body (11) extending into the fluid channel; a small hole or a gap is provided on the piston (12).

9. The variable stiffness seismic isolation structure system of pillar-type equipment according to claim 8, characterized in that: The material of the damping medium (14) is selected from one or more of dimethyl silicone oil, polyurethane, and acrylic acid.

10. A variable stiffness seismic isolation method for pillar-type equipment, characterized in that: The method uses the system according to any one of claims 1 to 9 to perform variable stiffness seismic isolation of substation pillar equipment, and the method comprises the following steps: When the system is in a vibrating state, the hinged characteristics of the diagonal rod (2) cause the horizontal distance between the column limbs (1) to shorten under vertical bending deformation, thereby driving the upper end of the diagonal rod (2) to move along the slide rail (6), and the variable stiffness isolation energy dissipation connection group (3) accordingly provides a variable negative stiffness that increases with displacement, thereby reducing the natural frequency of the structure. The vertically assembled variable stiffness isolation energy dissipation connection group (3) also plays a role in vertical isolation, thereby realizing three-dimensional enhanced isolation and nonlinear enhanced energy dissipation. The energy consumption of the system is enhanced by relative sliding between the upper end of the inclined rod (2) and the friction inner plate (5); The self-resetting ribs (4) provide a self-resetting control force for the deformed pillar-like structure, so that the structure returns to its initial static state; Under static load, the vertical spring (9) provides stable support and shares the vertical bearing force acting on the upper end of the diagonal rod (2), and the horizontal spring (10) is in a pre-stressed state; under vibration, the upper end of the diagonal rod (2) moves along the direction of the slide rail (6), driving the vertical spring (9) to deform. At this time, the vertical spring (9) continues to bear the vertical load and adapt to the displacement, and the horizontal spring (10) is deformed through the negative stiffness effect to reduce vibration transmission, and the viscous damper (8) realizes energy dissipation.

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