Semi-active Tuned Mass Damper Based on Smart Materials

Abstract

The present invention provides a semi-active tuned mass damper based on intelligent materials, comprising: a passive control part, an intelligent control part, a first-stage vibration reduction part, a second-stage vibration reduction part and a health monitoring part, wherein the intelligent control part uniformly controls the first-stage vibration reduction part, the second-stage vibration reduction part and the health monitoring part; the tuned mass damper of the present invention can achieve two-way vibration control of a building structure, real-time monitor the vibration responses of the tuned mass damper and the main structure, and start the semi-active control of the intelligent materials after the computer control system collects and analyzes data.

Description

Technical Field

[0001] The present invention belongs to the technical fields of civil engineering and vibration control, and particularly relates to a semi-active tuned mass damper based on intelligent materials. Background Art

[0002] With the development of structural design and construction technologies, building structures have become taller and more slender. However, due to their slender shapes, high-rise buildings have low natural vibration frequencies and damping ratios, and thus are very sensitive to dynamic responses under natural disasters. Earthquakes are one of the most destructive and dangerous natural disasters. How to protect the safety of building structures under earthquake actions has always been a research hotspot among scholars in the world's civil engineering field. With people's higher requirements for the safety of building structures, it is challenging and of great value to conduct research on intelligent disaster prevention and mitigation of structures under earthquake actions.

[0003] A tuned mass damper (TMD for short) is a traditional structural vibration control device. A tuned mass damper is a single-degree-of-freedom vibration absorber composed of a mass unit, a stiffness unit, and a damping unit. It can be adjusted so that its natural vibration frequency is the same as a certain order of frequency that the structure needs to control. When an external excitation acts on the structure and causes it to vibrate horizontally, the tuned mass damper acts on the structure with a reverse inertial force to control the vibration of the structure, and the damping unit dissipates the vibration energy. However, traditional passive tuned mass dampers have the disadvantage of being sensitive to frequency tuning. When their frequencies deviate from the structure frequency, their control effects will be significantly reduced. In order to improve the multi-disaster control effect of the tuned mass damper and make it have a certain adaptability, it is very meaningful to study a semi-active tuned mass damper that can spontaneously change parameters to enhance the energy dissipation and shock absorption effect.

[0004] Actual natural disasters are two-way inputs, while conventional tuned mass dampers can only control unidirectional structural vibrations. In order to control the two-way seismic response of the structure, one method is to arrange a tuned mass damper in each of the two directions in the plane, but this will increase the amount of mechanical devices, increase the economic investment, increase the building occupied space, and also bring a greater vertical load burden to the structure. In summary, in order to protect the safety of building structures under two-way disaster actions and have the advantages of saving damper electromechanical devices and saving electric energy, it is very necessary to propose a semi-active tuned mass damper for two-way energy dissipation and shock absorption. Summary of the Invention

[0005] The purpose of the present invention is to overcome the deficiencies in the prior art and provide a semi-active tuned mass damper based on intelligent materials, which improves the two-way energy dissipation and shock absorption performance.

[0006] The purpose of the present invention is achieved by the following technical solutions:

[0007] A semi-active tuned mass damper based on intelligent materials, comprising: a mass block, high-strength steel ball rollers, a sliding frame, a lower connecting plate and a steel column bracket. The lower connecting plate is connected to the floor of a building structure by welding or bolts. The sliding frame is placed on the lower connecting plate. A piezoelectric ceramic sliding surface is placed on the upper surface of the sliding frame. The bottom surface of the mass block is connected to the high-strength steel ball rollers through bearings. The high-strength steel ball rollers are placed on the upper surface of the sliding frame and can roll freely in two directions. A magnetorheological elastomer spring is arranged between the mass block and the sliding frame, and both ends of the magnetorheological elastomer spring are clamped to the mass block and the sliding frame respectively. The steel column bracket is connected to the edge of the lower connecting plate by welding or bolts. A shape memory alloy spring passes through an electrorheological damper, and both ends of the shape memory alloy spring are clamped to the steel column bracket (7) and the sliding frame (4) respectively through reserved fasteners. A three-axis vibration sensor I is adsorbed on the side surface of the steel column bracket for measuring the X, Y, and Z three-axis vibration responses of the steel column bracket. A three-axis vibration sensor II is adsorbed on the side surface of the mass block for measuring the X, Y, and Z three-axis vibration responses of the mass block. The three-axis vibration sensor I and the three-axis vibration sensor II are respectively connected to a computer control system through wired or wireless transmission.

[0008] The intelligent materials refer to the piezoelectric ceramic sliding surface, the magnetorheological elastomer spring, the electrorheological damper and the shape memory alloy spring.

[0009] The mass block, the high-strength steel ball rollers, the sliding frame and the lower connecting plate form the passive control part of the semi-active tuned mass damper.

[0010] The three-axis vibration sensor I, the three-axis vibration sensor II and the computer control system form the intelligent control part of the semi-active tuned mass damper. The computer control system obtains the two-way optimal frequency and damping ratio of the semi-active tuned mass damper by analyzing and processing the sensing signals of the three-axis vibration sensor I and the three-axis vibration sensor II, and then starts the semi-active control of the intelligent materials.

[0011] The piezoelectric ceramic sliding surface and the magnetorheological elastomer spring form a first-stage vibration reduction part of the semi-active tuned mass damper. The piezoelectric ceramic sliding surface changes its own material properties under the drive of the computer control system to improve the vibration reduction performance of the damper. The magnetorheological elastomer spring changes the electric current and magnetic field under the drive of the computer control system to adjust the frequency and damping ratio of the damper. In the first-stage vibration reduction part, the piezoelectric ceramic sliding surface is used to realize the intelligent control of the mass block, improve its energy dissipation and vibration reduction performance in two-way in-plane, and the magnetorheological elastomer spring is used as the stiffness and damping unit of the mass block. The computer control system can change the electric current and magnetic field of the magnetorheological elastomer spring, thereby adjusting the frequency and damping ratio of the damper and improving its two-way vibration reduction effect.

[0012] The steel column bracket, the electrorheological damper and the shape memory alloy spring form a second-stage vibration reduction part of the semi-active tuned mass damper. The electrorheological damper changes the electric current under the drive of the computer control system to change the damping ratio. The shape memory alloy spring changes the electric current under the drive of the computer control system to change the stiffness and damping ratio. Thus, they jointly and real-time adjust the stiffness and damping ratio of the overall mass block and the sliding frame under large-amplitude vibration, achieving the effects of controlling the structural dynamic response, reducing the stroke of the damper and limiting the position. In the second-stage vibration reduction part, the mass block will slide on the lower connecting plate together with the sliding frame, and the electrorheological damper and the shape memory alloy spring jointly provide semi-active restoring force and damping force, which can reduce the stroke of the damper and limit the position while improving the vibration reduction effect.

[0013] The three-axis vibration sensor I, the three-axis vibration sensor II and the computer control system form a health monitoring part of the semi-active tuned mass damper. The real-time vibration signals of the semi-active tuned mass damper and the building structure are stored, transmitted and analyzed in real time by the health monitoring part to ensure the normal operation and safety of the building structure and the tuned mass damper.

[0014] Wherein, one piece of the steel column bracket, the electrorheological damper and the shape memory alloy spring is a set of kits. The semi-active tuned mass damper is provided with 4 to 8 sets of the kits, and each set of kits is evenly distributed around the sliding frame in a rotating manner.

[0015] Wherein, the three-axis sensors used can be acceleration sensors, velocity sensors or displacement sensors, etc.

[0016] For the semi-active tuned mass damper based on intelligent materials as proposed above in the present invention, due to the adoption of the above scheme, the beneficial effects of the present invention are:

[0017] First, the tuned mass damper of the present invention can simultaneously control the two-way vibration of a high-rise building in the plane, and has the advantages of saving building use space, reducing the amount of dampers, reducing the concentrated load on the floor, and saving costs.

[0018] Second, the tuned mass damper of the present invention can start to work under relatively small wind vibrations. By changing the mechanical properties of the rolling surface through the piezoelectric ceramic sliding surface, the frequency and damping ratio of the damper are changed, and a semi-active restoring force and damping force are provided by the magnetorheological elastomer spring to improve its two-way energy dissipation and shock absorption performance.

[0019] Third, since the tuned mass damper of the present invention can adjust its two-way frequency and damping ratio in real time, it has better two-way vibration control performance than traditional tuned mass dampers.

[0020] Fourth, under large-amplitude vibrations, the tuned mass damper of the present invention can improve its control effect through structural forms such as the common sliding of the electrorheological damper, the shape memory alloy spring, and the sliding frame, reduce the stroke of the mass block, and play a better limiting role.

[0021] Fifth, the real-time vibration signals of the tuned mass damper and the main structure of the present invention are stored, transmitted, and analyzed in real time by the health monitoring part to ensure the normal operation and safety of the main structure and the tuned mass damper. Description of the Drawings

[0022] Figure 1 It is a schematic structural diagram of the semi-active tuned mass damper based on intelligent materials of the present invention.

[0023] Figure 2 It is a top view of a preferred embodiment of the semi-active tuned mass damper based on intelligent materials of the present invention.

[0024] Figure 3 It is a top view of another preferred embodiment of the semi-active tuned mass damper based on intelligent materials of the present invention.

[0025] Figure 4 It is a control algorithm flowchart of the semi-active tuned mass damper based on intelligent materials of the present invention.

[0026] Reference numerals: 1 - mass block, 2 - high-strength steel ball rollers, 3 - piezoelectric ceramic sliding surface, 4 - sliding frame, 5 - lower connecting plate, 6 - magnetorheological elastomer spring, 7 - steel column bracket, 8 - electrorheological damper, 9 - shape memory alloy spring, 10 - computer control system, 11 - three-way vibration sensor I and 12 - three-way vibration sensor II. Detailed Embodiments

[0027] The present invention will be further described below in conjunction with the accompanying drawings and embodiments. However, these embodiments are not intended to limit the present invention. Any similar structures and their similar variations that adopt the present invention should be included in the protection scope of the present invention.

[0028] The semi-active tuned mass damper based on intelligent materials of the present invention includes: a passive control part, an intelligent control part, a first-stage vibration reduction part, a second-stage vibration reduction part, and a health monitoring part. Among them, the intelligent control part uniformly controls the first-stage vibration reduction part, the second-stage vibration reduction part, and the health monitoring part.

[0029] Specifically, it includes: a mass block 1, high-strength steel ball rollers 2, a sliding frame 4, a lower connecting plate 5, and a steel column bracket 7. The lower connecting plate 5 is connected to the floor of the building structure by welding or bolts. The sliding frame 4 is placed on the lower connecting plate 5. A piezoelectric ceramic sliding surface 3 is placed on the upper surface of the sliding frame 4. The bottom surface of the mass block 1 is connected to the high-strength steel ball rollers 2 through bearings. The high-strength steel ball rollers 2 are placed on the upper surface of the sliding frame 4 and can roll freely in two directions. A magnetorheological elastomer spring 6 is arranged between the mass block 1 and the sliding frame 4, and both ends of the magnetorheological elastomer spring 6 are respectively clamped to the mass block 1 and the sliding frame 4. The steel column bracket 7 is connected to the edge of the lower connecting plate 5 by welding or bolts. A shape memory alloy spring 9 passes through an electrorheological damper 8, and both ends of the shape memory alloy spring 9 are respectively clamped to the steel column bracket 7 and the sliding frame 4 through reserved fasteners. A three-axis vibration sensor 11 is adsorbed on the side of the steel column bracket 7 to measure the X, Y, and Z three-axis vibration responses of the steel column bracket 7. A three-axis vibration sensor 12 is adsorbed on the side of the mass block 1 to measure the X, Y, and Z three-axis vibration responses of the mass block 1. The three-axis vibration sensor 11 and the three-axis vibration sensor 12 are respectively connected to a computer control system 10 through wired or wireless transmission.

[0030] The intelligent materials described in the present invention refer to the piezoelectric ceramic sliding surface 3, the magnetorheological elastomer spring 6, the electrorheological damper 8, and the shape memory alloy spring 9.

[0031] Among them, one steel column bracket 7, one electrorheological damper 8, and one shape memory alloy spring 9 are a set of kits. The semi-active tuned mass damper is provided with 4 to 8 sets of such kits, and each set of kits is evenly rotationally distributed around the sliding frame 4.

[0032] As Figure 2 In a preferred embodiment of the present invention as described above, four sets of steel column brackets 7, electrorheological dampers 8, and shape memory alloy springs 9 are evenly rotationally distributed around the sliding frame 4. In each set of kits, one end of the shape memory alloy spring 9 is connected to the steel column bracket 7 located at a corner of the lower connecting plate 5, and the other end is connected to a corner farther away from the sliding frame 4. The four sets of kits are connected in sequence, so as to be evenly rotationally distributed around the sliding frame 4.

[0033] In Figure 3 another preferred embodiment of the present invention as shown, eight sets of steel column brackets 7, electrorheological dampers 8 and shape memory alloy springs 9 are evenly and rotationally distributed around the sliding frame 4. In addition to being arranged at the four corners of the lower connecting plate 5, a steel column bracket 7 is also arranged in the middle between two corners; correspondingly, fasteners are also reserved in the middle between two corners of the sliding frame 4. If one end of the shape memory alloy spring 9 is connected to the steel column bracket 7 located at the corner, the other end is connected to the middle of the sliding frame 4; correspondingly, if one end of the shape memory alloy spring 9 is connected to the steel column bracket 7 located between two corners, the other end is connected to a corner farther away on the sliding frame 4. The eight sets of kits are connected in sequence, so as to be evenly and rotationally distributed around the sliding frame 4.

[0034] Among them, the three-axis vibration sensors 11 and 12 used can be acceleration sensors, velocity sensors, displacement sensors, etc.

[0035] Passive control part

[0036] The passive control part includes: a mass block 1, high-strength steel ball rollers 2, a sliding frame 4 and a lower connecting plate 5. The mass block 1 can roll smoothly in two directions in the plane through the high-strength steel ball rollers 2 to realize the two-way vibration control of the building structure.

[0037] Intelligent control part

[0038] The intelligent control part includes: a computer control system 10, a three-axis vibration sensor 11 and a three-axis vibration sensor 12. The computer control system 10 can monitor the vibration responses of the tuned mass damper and the building structure in real time. By analyzing and processing the sensing signals of the three-axis vibration sensor 11 and the three-axis vibration sensor 12, the phase angle of the sensing signals is solved in real time, the derivative is calculated, the upper and lower limits of the window are controlled, and the instantaneous optimal frequency is calculated, generally 0.1 - 1.0 Hz; the computer control system 10 calculates the optimal damping ratio through integration based on the algorithm with the minimum acceleration vibration amplitude of the building structure as the optimization target, generally 0 - 12%. Then they are respectively fed back to the semi-active control part to start the semi-active control of the intelligent material, and the stiffness and damping are adjusted in sequence and in real time. The specific method for the computer control system to process and calculate the collected data does not belong to the technical problems to be solved by the present invention and is the prior art known to those skilled in the art, so it will not be elaborated here.

[0039] First-stage vibration damping part

[0040] The first-stage vibration reduction part includes: a piezoelectric ceramic sliding surface 3 and a magnetorheological elastomer spring 6. The piezoelectric ceramic sliding surface 3 changes its own material properties under the drive of the computer control system 10 to improve the vibration reduction performance of the damper. The magnetorheological elastomer spring 6 changes the electric current passing through and the magnetic field under the drive of the computer control system 10 to adjust the frequency and damping ratio of the damper. In the first-stage vibration reduction part, the piezoelectric ceramic sliding surface 3 is used to achieve intelligent control of the mass block 1, improve its energy dissipation and vibration reduction performance in the two-way plane, and the magnetorheological elastomer spring 6 is used as the stiffness and damping unit of the mass block 1. The computer control system 10 can change the electric current passing through and the magnetic field of the magnetorheological elastomer spring 6, thereby adjusting the frequency and damping ratio of the damper and improving its two-way vibration reduction effect.

[0041] Second-stage vibration damping part

[0042] The second-stage vibration reduction part includes: a steel column bracket 7, an electrorheological damper 8 and a shape memory alloy spring 9. The electrorheological damper 8 changes the electric current passing through under the drive of the computer control system 10 to change the damping ratio. The shape memory alloy spring 9 changes the electric current passing through under the drive of the computer control system 10 to change the stiffness and damping ratio. Thus, the stiffness and damping ratio of the whole mass block 1 and the sliding frame 4 under large-amplitude vibration are jointly adjusted in real time, achieving the effects of controlling the structural dynamic response, reducing the stroke of the damper and limiting the position. In the second-stage vibration reduction part, the mass block 1 and the sliding frame 4 will jointly slide on the lower connecting plate 5, and the electrorheological damper 8 and the shape memory alloy spring 9 jointly provide semi-active restoring force and damping force, which can reduce the stroke of the damper and limit the position while improving the vibration reduction effect.

[0043] Health monitoring part

[0044] The health monitoring part includes: a computer control system 10, a three-way vibration sensor 11 and a three-way vibration sensor 12. The real-time vibration signals of the semi-active tuned mass damper and the building structure are stored, transmitted and analyzed in real time by the health monitoring part to ensure the normal operation and safety of the building structure and the tuned mass damper.

[0045] The above description is only a description of the preferred embodiments of the present invention, and is not any limitation on the scope of the present invention. Any change or modification made by any ordinary technician familiar with the field according to the disclosed technical content should be regarded as an equivalent effective embodiment, and all belong to the scope protected by the technical solution of the present invention.

Claims

1. A semi-active tuned mass damper based on intelligent materials, characterized in that, Including: A mass block (1), high-strength steel ball rollers (2), a sliding frame (4), a lower connecting plate (5), and a steel column support (7). The lower connecting plate (5) is connected to the floor of the building structure by welding or bolts. The sliding frame (4) is placed on the lower connecting plate (5). A piezoelectric ceramic sliding surface (3) is placed on the upper surface of the sliding frame (4). The bottom surface of the mass block (1) is connected to the high-strength steel ball rollers (2) through bearings. The high-strength steel ball rollers (2) are placed on the upper surface of the sliding frame (4) and can roll freely in two directions. A magnetorheological elastomer spring (6) is arranged between the mass block (1) and the sliding frame (4), and both ends of the magnetorheological elastomer spring (6) are clamped to the mass block (1) and the sliding frame (4) respectively. The steel column support (7) is connected to the edge of the lower connecting plate (5) by welding or bolts. A shape memory alloy spring (9) passes through an electrorheological damper (8), and both ends of the shape memory alloy spring (9) are clamped to the steel column support (7) and the sliding frame (4) respectively through reserved fasteners. A three-axis vibration sensor I (11) is adsorbed on the side surface of the steel column support (7) to measure the X, Y, and Z three-axis vibration responses of the steel column support (7). A three-axis vibration sensor II (12) is adsorbed on the side surface of the mass block (1) to measure the X, Y, and Z three-axis vibration responses of the mass block (1). The three-axis vibration sensor I (11) and the three-axis vibration sensor II (12) are respectively connected to a computer control system (10) through wired or wireless transmission; Wherein: The mass block (1), the high-strength steel ball rollers (2), the sliding frame (4), and the lower connecting plate (5) form the passive control part of the semi-active tuned mass damper; The three-axis vibration sensor I (11), the three-axis vibration sensor II (12), and the computer control system (10) form the intelligent control part of the semi-active tuned mass damper. The computer control system (10) obtains the two-way optimal frequency and damping ratio of the semi-active tuned mass damper by analyzing and processing the sensing signals of the three-axis vibration sensor I (11) and the three-axis vibration sensor II (12); The piezoelectric ceramic sliding surface (3) and the magnetorheological elastomer spring (6) form the first-stage vibration reduction part of the semi-active tuned mass damper. The piezoelectric ceramic sliding surface (3) changes its own material properties under the drive of the computer control system (10) to improve the vibration reduction performance of the damper. The magnetorheological elastomer spring (6) changes the electric current and magnetic field under the drive of the computer control system (10) to adjust the frequency and damping ratio of the damper; The steel column bracket (7), the electrorheological damper (8) and the shape memory alloy spring (9) form the two-stage vibration reduction part of the semi-active tuned mass damper. The electrorheological damper (8) changes the power-on amount under the drive of the computer control system (10) to change the damping ratio, and the shape memory alloy spring (9) changes the power-on amount under the drive of the computer control system (10) to change the stiffness and damping ratio, so as to jointly and real-time adjust the stiffness and damping ratio of the overall mass block (1) and the sliding frame (4) under large-amplitude vibration, achieving the effects of controlling the structural dynamic response, reducing the damper stroke and limiting; The three-axis vibration sensor I (11), the three-axis vibration sensor II (12) and the computer control system (10) form the health monitoring part of the semi-active tuned mass damper. The real-time vibration signals of the semi-active tuned mass damper and the building structure are stored, transmitted and analyzed in real time by the health monitoring part.

2. The semi-active tuned mass damper according to claim 1, wherein: One piece of the steel column bracket (7), the electrorheological damper (8) and the shape memory alloy spring (9) is a set of kits. The semi-active tuned mass damper is provided with 4 to 8 sets of the kits, and each set of kits is evenly and rotationally distributed around the sliding frame (4).

3. The semi-active tuned mass damper according to claim 1, characterized in that: The three-axis vibration sensor I (11) and the three-axis vibration sensor II (12) are acceleration sensors, velocity sensors or displacement sensors.

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