863 results about "Structural vibration" patented technology

The invention specifically relates to a mass tuned vibration reducer used for controlling the vibration of an aerobridge in the airport, a large-span pedestrian bridge, a port trestle, high-rise buildings and the related structures. The mass tuned vibration reducer comprises a mass block, a spring, a damper and a base; wherein, the spring can be a spiral spring, a disc spring or a plate spring, and the end part of the spring is provided with a rigidity regulating device. The mass tuned vibration reducer can successfully realize the regulation on the natural frequency of a TMD system under the condition of needing not to assemble and disassemble the TMD since the end part of the spring is provided with the rigidity regulating device, so as to simplify the difficulty of regulation work, avoid the waste of manpower and materials and greatly reduce the construction cost. Meanwhile, the natural frequency and the damping of the system can be regulated in an optimized way under the condition of needing not to assemble and disassemble the TMD, thereby better exerting the vibration absorption performance of the mass tuned vibration reducer, ensuring safety and stableness of the pedestrians and vehicles on the large-span bridge and the thin and high building, contributing to prolonging the service lives of the thin and high building and the bridge, and having remarkable economic and social benefits.

The invention specifically relates to a mass tuned vibration reducer used for regulating the subsidence ratio of the vibration of the related structures. The mass tuned vibration reducer comprises a mass block, a spring, a damper and a base, and is characterized in that the damper is an adhesion-type damper formed by a damping cylinder, adhesive damping fluid and a piston, wherein, the piston and the adhesive damping fluid are arranged in the damping cylinder, and at least part of the piston is immerged into the adhesive damping fluid. The mass tuned vibration reducer adopts the adhesion-type damper formed by the adhesive damping fluid and the piston and can provide three dimensional damping, so as to effectively prevent side tumbling and ensure the vibration reducer realizes smooth actions; vibration mass is not needed to be provided with a special guide device, so that the mass tuned vibration reducer has reliable work and higher cost performance, and basically needs no maintenance. Meanwhile, the mass tuned vibration reducer realizes the aim of regulating the natural frequency and the subsidence ratio at any time, thus better exerting the vibration absorption performance of the mass tuned vibration reducer, ensuring stableness and safety of the pedestrians and vehicles on the large-span bridge and the thin and high building, contributing to prolonging the service lives of the thin and high building and the bridge, and having remarkable economic and social benefits.

A vehicle system structure vibration and noise transmission path detecting system belongs to the technical field of automobile design. In the invention, a vehicle system analysis model building module builds incentive related bus, vehicle structure and acoustic cavity models and sets up a vehicle system analysis model; a vibration or noise response spectrum acquiring module acquires the vehicle structure vibration or passenger indoor structure noise response analysis; a transfer path power calculating module calculates the transfer power of all transfer paths and the total power transferred to the vehicle; a main transfer path detecting module calculates and orders the contribution of all the transfer paths, and identifies the main transfer paths; an optimized design module identifies the main influential factors for transfer of the power flow of the main transfer paths, applies an optimized design method to improve relevant bus characteristic parameters and structure types, and verifies the parameters in the vehicle system or the vibration absorbing and noise reducing effect after structure improvement. The vehicle system structure vibration and noise transmission path detecting system can improve the accuracy of transfer path identification and possibility of effective control to the transfer paths.

Methods and apparatus for actively damping vibrations associated with a optical assembly of a photolithographic system are disclosed. According to one aspect of the present invention, an assembly that provides damping to a structure of a photolithographic apparatus that is subject to structural oscillations includes a counter mass, an active mechanism, an a controller. The active mechanism is coupled to the structure, supports the counter mass, and applies a force to the structure to counteract structural oscillations in the structure. The controller controls the force applied by the active mechanism on the structure, and utilizes information associated with movement of the structure to control the force.

The invention relates to a horizontal vibration energy-absorbing and vibration-damping device used for large engineering structures such as a longspan foot bridge, belonging to the field of vibration control of civil engineering structures. The horizontal vibration energy-absorbing and vibration-damping device comprises a constant strength cantilever beam consisting of struts at two sides and a cross beam, two ends of the cross beam are respectively and correspondingly connected with the struts at two sides, and the bottom ends of the struts at two sides are fixed on a foundation. The horizontal vibration energy-absorbing and vibration-damping device is characterized in that the upper end of a mass block is connected with the cross beam, the lower end of the mass block is provided with a rectangular permanent magnet; and one side of the lower part of the mass block is provided with a copper plate fixedly arranged on the foundation through a supporting member, and a gap is reserved between the copper plate and the rectangular permanent magnet. The invention ensures that the rigidity and the dampness of the tuned mass damper system realize complete separation, easily realizes that the damping ratio of TMD is continuously adjustable within a larger range though regulating the gap between the permanent magnet and the copper plate, and effectively solves the problems of oil leakage failure in the conventional TMD, difficult regulation of the damping parameters and interference on the frequency.

The invention provides a health monitoring system for a concrete structure. The health monitoring system comprises a sensor subsystem, a data acquiring subsystem, a communication system and a monitoring center. The sensor subsystem comprises a piezoelectric intelligent aggregate sensor and other sensors, wherein the piezoelectric intelligent aggregate sensor is used for monitoring cracks of the concrete structure, a piezoelectric force sensor is used for acquiring impact load of the structure, and an acceleration sensor is used for obtaining structural vibration information. The data acquiring subsystem is mainly composed of a data acquisition card and ancillary facilities including a piezoelectric ceramic driving power supply, a charge amplifier and the like. A communication subsystem adopts a wired mode and is communicated with an upper computer in a mode that a transmission control protocol (TCP)/Internet protocol (IP) is built in Ethernet. The monitoring center mainly comprises a driving monitoring module, a driven monitoring module, an acceleration monitoring module and other software functional modules. The health monitoring system for the concrete structure is simple to operate, and strong in man-machine interaction, can be expanded according to actual requirements at a later stage, and is very suitable for health monitoring of the concrete structure in practical engineering.

The invention provides a testing method of a vibration response test for a high-tower structure of transmission line of transmission of vibration signals and stimulation by taking wind load as external environment in a wireless mode. The method has the characteristics of simple and convenient operation and analysis and higher precision compared with the traditional vibration response testing means in a wired transmission and hammer method. Therefore, relational environment parameters motivated by environment are confirmed through a meteorological environment monitoring device, the vibration response of an iron tower is tested by the selected accelerating sensor, the test data of the vibration response of the high-tower structure of transmission line is transmitted by applying the wireless sensor, and finally modal mode parameters of the high-tower structure of transmission line is confirmed through the back-end process of the monitoring system.

The invention provides an air supply system for a large-volume air cooled refrigerator and the air-cooled refrigerator. The air supply system comprises an air channel and a draught fan, wherein a centrifugal draught fan with bidirectional air outlets is adopted by the draught fan. The invention further provides the air-cooled refrigerator adopting the air supply system. According to the air supply system for the large-volume air-cooled refrigerator and the air-cooled refrigerator, the novel centrifugal draught fan is adopted for being matched with reasonable air channel design, good flow tracks are obtained, structural vibration and pneumatic noise of the air supply system are reduced, the space occupied by the air supply system is reduced, the volume of the inner container of the refrigerator is increased, cost is reduced, energy consumption is lowered, energy is saved, and emission is reduced.

The invention provides an adjustable damping energy storage type tuned mass damper. A damping adjusting device of a damper of consists of a permanent magnet, coils, auxiliary rods, an energy storage battery, an adjustable resistor, a light-emitting diode (LED) pre-warning indicator light; in the reciprocating motion process that the damper absorbs the vibration energy of a main structure so as to generate inertial mass, a cylindrical spiral spring provides damping, the permanent magnet generates a variable magnetic field, induced electromotive force is generated in the coils so as to generate induction current, and the induction current generates electromagnetic damping to inhibit the movement of the permanent magnet; the adjustable resistor in the damping adjusting device is adjusted, so the magnitude of the electromagnetic damping is changed, and the damping ratio of a structure reaches the optimum damping ratio; and residual energy is recovered by using the energy storage battery, the LED pre-warning indicator light provides a pre-warning indication for a pedestrian and a vehicle, and multiple effects of vibration controlling, clean energy recovery, pre-warning and alarming of vibration conditions and the like.

The invention relates to an application field of magnetorheological damping, and provides a control method for magnetorheological damping, which is characterized in that: an input magnetic loop is formed by adopting a giant magnetostrictive material, a permanent magnet and magnetic yokes at both ends; an output magnetic loop is composed of a permanent magnet, a magnetic yoke and a magnetorheological medium. The control method can dispense with coil and exterior power supply, and the conversion from the controlled structure vibration mechanical energy to magnetic field energy can be achieved only by using less materials; thereby the control method for magnetorheological damping has the advantages of non-energy device, large load, great damping force, rapid response, broadband and better buffering to the impact load.

The invention discloses a structural finite-element parametric modeling method applicable to a grating-configuration rudder surface. According to the method, a mapping transformation method based on a finite element model and a parametric approach to achieving conversion from two-dimensional mesh parameterization division to three-dimensional appearance expansion are adopted. The method includes the steps of specifically conducting two-dimensional plane projection on the grating-configuration rudder surface, extracting characteristic parameters, and conducting two-dimensional parameterization division; building a mapping relation between a two-dimensional finite element mesh and a three-dimensional finite element mesh, designing a numbering rule for finite element mesh points, and achieving conversion from the two-dimensional mesh to the three-dimensional appearance expansion; by means of a high-level computer language program, implementing the structural finite-element parametric modeling procedures for the grating-configuration rudder surface. By using the method, in a conceptual design phase or a preliminary design phase, the structural modeling efficiency can be greatly increased, the costs of time and manpower are low, parameters of self-compiled programs can be adjusted quickly, analysis applicability is high, the obtained model is applicable to analytical calculation of structural vibration, structural dynamics and the like, and the method is applicable to grating-configuration rudder surfaces and grating-configuration airfoils.

The invention relates to a nonlinear rail type collaborative tuning damper which comprises an external cavity unit, a spring system, a viscous liquid, an internal cavity unit, a cushioning material and a particle group. Two groove rails which are arranged in the length direction of the cavity are arranged at the bottom of the damper external cavity unit, the internal cavity unit can slide back and forth along the groove rails and is connected with the inner wall of the external cavity through the spring system, the portion between the external cavity unit and the internal cavity unit is filled with the viscous liquid, the inner wall and bottom of the internal cavity are covered with the cushioning material, and the particle group is composed of circular particles with different sizes. Shaking of the viscous liquid enables the internal cavity to move back and forth to consume energy, and friction and collision of the liquid and the container wall provides the damping effect; the structure self-vibration frequency is tuned by the spring system, and the energy is consumed by means of the collision and friction between the particles or between the particles and the cavity wall. According to the nonlinear rail type collaborative tuning damper, the advantages of various dampers are combined, the vibration damping frequency band is wide, the effect is good, and the nonlinear rail type collaborative tuning damper has wide applicability in the field of civil engineering structure vibration control.

The invention provides a binocular photogrammetry method of large flexible structure vibration displacement, and belongs to the technical field of flexible structure dynamic analysis and measurement. The binocular photogrammetry method of large flexible structure vibration displacement aims to solve the problem that the existing contact measurement impacts performance of a flexible structure. Firstly, industrial cameras are demarcated; then, shock excitation is conducted on the flexible structure to be tested, all the industrial cameras are controlled to be triggered synchronously through a single-chip microcomputer, and shooting of vibration displacement is conducted on the point to be tested of the flexible structure to be tested; next, images obtained by shooting of all the industrial cameras are dealt with, pixel coordinates of the point to be tested are obtained through an angular point detection algorithm, object space coordinates of the point to be tested at each point of time are obtained through a binocular three-dimensional reconstruction technology, and thus the vibration displacement curve of the flexible structure to be tested is obtained. The binocular photogrammetry method of large flexible structure vibration displacement is applied to measuring vibration displacement of the flexible structure.

The invention relates to a test platform and method for simulating intelligent flexible space panel structure vibration active control. The test platform includes a mechanical clamping device, a vibration flexible plate, a signal generator, a high-performance DSP board, an oscillator, a computer, a display device, a vibrator, a plurality of charge amplifier, a plurality of low-pass filter, a plurality of piezoelectric power amplifier, a piezoelectric plate sensing network and a piezoelectric driving network. The invention which uses piezoelectric ceramic element as basic materials of sensor network and driver network, DSP measuring element as core of signal detection, arithmetic operation and output control signal, PC machine as test control platform and observing interface provides a test platform and test method based on analog piezoelectric intelligent flexible space panel structure vibration active control research.

The invention relates to a method for controlling the structural modal vibration of a dual-frame magnetic levitation control moment gyroscope (CMG). On the basis of establishing a nominal model of an electromagnet rotor system, a sine-swept excitation mode is adopted to perform the identification of frequency domains on an electromagnet rotor and measure the disturbance of system parameters, the properties of structural vibration modality and the high-frequency unmodeled dynamics of an electromagnet rotor model; and a comprehensive robust control method of a structural singular value mu is utilized to select a weighting function and inhibit the structural modal vibration. The method belongs to the technical field of aerospace control, and can be used for inhibiting the structural modal vibration of the dual-frame magnetic levitation CMG.

The invention belongs to the technical field of damping for civil engineering structure, and particularly relates to a tuned mass damper used for controlling the low-frequency vibration of a building structure. The tuned mass damper comprises suspension components, a damping device and a mass block and is characterized by further comprising at least one swing support, when more than one swing support is arranged, the swing supports are nested from outside to inside, the lower part of each swing support is connected with the adjacent suspension component at the outer side of the swing support, and the upper part of the swing support is connected with the adjacent suspension component at the inner side of the swing support; the lower end of the adjacent suspension component at the inner side of the swing support is further connected with the adjacent swing support at the inner side of the suspension component or with the mass block; and the damping device is connected with the mass block. The tuned mass damper is compact in spatial structure, suitable for control on the vibrations of structures with frequencies of 0.15 Hz and even lower, great in cost performance, capable of effectively expanding the application range of swing-type tuned mass damper products, and very wide in market application prospect.

The invention discloses a driven viscous damper adjustable in damping force, and belongs to the technical field of civil engineering structural vibration damping. According to the driven viscous damper adjustable in damping force, the Bang-Bang active control algorithm principle is used, the character that a directional gear which can anticlockwise rotate and a directional gear which can clockwise rotate can only rotate in one direction is used, and therefore a mechanism which is composed of directional gears, free gears, a rack track, baffles and a viscous damper is designed. When interlayer displacement occurs in the structure, the process where displacement returns to the balance position is not influenced by inhibition action of the damping force of the viscous damper, and an oil damper is made to be more effective in structural vibration damping control.

The invention provides a ship structure vibration and noise forecasting system based on S-P-R, comprising a database module, a modeling and calculating module, and a result processing module. The database module stores the vibration intensity data of various kinds of vibration sources in each cabin of a ship, and the noise intensity data of various kinds of noise sources; the modeling and calculating module comprises a ship modeling submodule, a key excitation source recognition submodule, a transmission path determination submodule, and a receiving station energy calculating module, and is used for defining transmission paths, calculating the transmission loss of the vibration/noise energy generated by each excitation source by the transmission to a receiving station along a transmission path, and then calculating the vibration/ noise total energy of the receiving station. The system of the invention combines an analysis method, a numerical method and an experimental method to analyze ship structure vibration source and transmission path characteristics, calculates cabin air noise levels according to the analysis procedure of an S-P-R method, and overcomes the problem that corresponding remedial measures can not be taken according to vibration and noise measurement results until a ship is completed.

The invention discloses an intelligent skin antenna electric compensation method based on an embedded fiber bragg grating. The method is characterized by comprising the steps that the fiber bragg grating is firstly embedded into a skin antenna structure, then sensed strain is converted into deformation displacement through a strain-displacement transfer matrix, finally the excitation current of a skin antenna is modified through sensed deformation displacement, and therefore the aim of the influence of compensation structure deformation on electric performance is achieved. The method has the advantages that the mechanical property of the skin antenna structure can be monitored in real time, health monitoring on the structure is achieved, and the problem that the electric performance of the skin antenna is lowered due to structural vibration and deformation on active service can be solved through the method. A fiber bragg grating sensor is light in mass and can be embedded into the structure, the pneumatic and invisible performance of an aircraft is not influenced, the fiber bragg grating sensor can be applied to the fields of airborne early warning aircrafts, warcrafts, unmanned aerial vehicles, invisible warships and the like, and the key technology for guaranteeing the reliable service of the performance of the skin antenna is achieved.

A self-powered self-induction magneto-rheological damper, including a connecting rod, an upper end cover, a stator, a first guide sleeve, a magnetic pole, a permanent magnet, an electromagnetic coil, a piston rod, a connecting end cover, a second guide sleeve, a seal, and a cylinder Body, piston with coil, bottom end cover, charge signal line, bottom earring, piezoelectric electrode, piezoelectric sheet, rubber sheet, air bag, wire and electric energy signal control module. The invention can adjust the size of the output damping force in real time according to the size of the external vibration force, thereby realizing the intelligent closed-loop control of the external vibration. The structural vibration control system based on the self-powered self-induction magneto-rheological damper will become very simple and greatly reduce the application cost because it does not require additional power input equipment and external vibration force test equipment, and is especially suitable for Applications where space is limited and power supply is inconvenient, such as: large buildings and bridges, etc.

The invention discloses a structural vibration and noise control device based on piezoelectric energy recovery, comprising a piezoelectric energy unit, a piezoelectricity sensing unit and a system circuit; wherein, a piezoelectric energy unit is composed of at least one first piezoelectric element which is stuck to the surface of a controlled structure and the piezoelectricity sensing unit is composed of at least one second piezoelectric element which is stuck to the surface of a controlled structure; the system circuit is composed of an energy recovery interface circuit unit, a maximum detecting unit, an initial charging circuit, a power management and an energy storage unit. The structural vibration and noise control device based on piezoelectric energy recovery of the invention uses the SSH energy recovery technology, recovers the energy from the piezoelectric patches which are stuck to the structure and provides energy for a low power control circuit (the power consumption of the control circuit is only 0.201mW); the invention is used to control the switch on the control device without external energy and enjoys simple structure, small volume and perfect robustness, thus having a wide application on structural vibration and noise control.

The invention relates to a modal parameter identification method based on response signal time-frequency joint distribution characteristics. According to the modal parameter identification method based on the response signal time-frequency joint distribution characteristics, signal analysis and structural modal parameter identification are carried out directly through a structural vibration response. The modal parameter identification method based on the response signal time-frequency joint distribution characteristics comprises the steps of firstly carrying out complex wavelet continuous transformation on a structural response signal, obtaining energy distribution characteristics of various wavelet transformation domains (a real domain, a virtual domain, a modal domain and a phase domain), obtaining a time average wavelet energy spectrum through a wavelet transformation coefficient, therefore carrying out quantification on selection of model orders and the scale corresponding to each order modality, on the basis, obtaining the optimum scale required by parameter identification, achieving pre-identification of modal frequency through the corresponding relation of the scale and the frequency, finally extracting a wavelet transformation coefficient slice at the specific scale, carrying out linear fitting through an amplitude value and a phase component, and achieving structural identification of inherent frequency and a damping ratio. As simulation and experiment results show, even if an external incentive function is not included, accurate identification of structural modal parameters can be achieved through the modal parameter identification method based on the response signal time-frequency joint distribution characteristics.