36 results about "Beam vibration" patented technology

The invention discloses a cantilever beam vibration control method based on rapid nonsingular terminal composite sliding mode control, and belongs to the field of vibration control. The method comprises the following steps: firstly, constructing a kinetic model of a piezoelectric cantilever beam, and establishing a state-space equation; then, according to a state-space equation of the piezoelectric cantilever beam, constructing an extended state observer, and obtaining estimated values of internal and external total disturbance, a displacement tracking error and a speed tracking error of the vibration control system; and finally, based on the internal and external total disturbance, displacement tracking error and speed tracking error of the vibration control system estimated by the extended state observer, constructing a rapid nonsingular terminal composite sliding mode controller, and using the controller to control a piezoelectric actuator on the piezoelectric cantilever beam. A convergence factor of a high-order exponential term is introduced into a nonsingular terminal sliding mode surface, so that a displacement tracking error and a speed tracking error of a vibration control system can be converged to zero within finite time, the problem of low convergence speed is solved, and meanwhile, the chattering phenomenon in the sliding mode control process is reduced.

The invention discloses a cantilever beam vibration absorber and a Tokamak device, and belongs to the field of vibration control. The cantilever beam vibration absorber comprises an acoustic black hole cantilever beam which comprises an acoustic black hole structure; the piezoelectric element is located on any surface of the acoustic black hole structure in the thickness direction; the piezoelectric shunt circuit is electrically connected with the piezoelectric element; the damping layer is located on at least one side of the acoustic black hole structure in the thickness direction; the tuned mass block is located on the side, away from the acoustic black hole structure, of the damping layer. Broadband vibration reduction can be achieved, the vibration reduction frequency is flexible, accurate and adjustable, and the vibration reduction effect is effectively improved.

A modular intelligent pipe support, belonging to the field of pipeline vibration control, includes a support body, sensors, a vibration signal acquisition, analysis, and alarm module, and a dynamic vibration absorption module. This invention is geared towards practical engineering applications. While retaining the boundary constraints and vibration control functions of existing pipe supports, it adds a modular device that integrates dynamic vibration absorption, energy harvesting, vibration monitoring, anomaly alarms, and wireless communication functions. This solves the problems of existing pipe supports having limited functionality, being unable to effectively handle pipeline spectrum vibrations, and requiring significant manpower and resources for routine safety inspections. Its core technology lies in utilizing a cantilever beam-mass block structure to provide targeted dynamic vibration absorption reaction force, effectively controlling pipeline spectrum vibrations; using piezoelectric materials to convert the mechanical energy generated during the cantilever beam vibration process into electrical energy, thereby powering the online monitoring module; and using sensors to collect the support vibration signals in real time, thus realizing the monitoring and analysis of support vibrations.

The utility model provides a vibration and noise reduction modular expansion device, which relates to the technical field of bridge construction and comprises deformed steel and a vibration and noise reduction device. The deformed steel comprises two deformed steel boundary beams arranged in parallel, the two deformed steel boundary beams are elastically connected, and anchoring assemblies are arranged at the bottoms of the sides, away from each other, of the two deformed steel boundary beams. The vibration and noise reduction device comprises two edge beam vibration and noise reduction toothed plates, the edge beam vibration and noise reduction toothed plates are correspondingly and fixedly installed on the deformed steel edge beam, each edge beam vibration and noise reduction toothed plate is composed of a plurality of edge beam comb-tooth-shaped unit plates, comb teeth are arranged on the opposite sides of the edge beam comb-tooth-shaped unit plates, and the comb teeth are arranged on the opposite sides of the edge beam comb-tooth-shaped unit plates. The surfaces of the edge beam comb-tooth-shaped unit plates are connected with edge beam vibration and noise reduction elastic layers, the edge beam vibration and noise reduction elastic layers are made of high-abrasion-resistance rubber, and anti-skid grooves are formed in the surfaces of the edge beam vibration and noise reduction elastic layers. The problem that the environment-friendly and low-noise performance of a wheel and an existing telescopic device is not ideal is solved.

An embodiment of the present invention provides a method for testing the tensile strength of flexible glass. The method comprises the following steps: obtaining the elastic modulus E of a first flexible glass sample through a cantilever beam vibration test; obtaining the distance D between opposite ends of the second flexible glass sample in its longitudinal direction under extreme bending conditions through a two-point bending test; establishing a three-dimensional model of the flexible glass that is in a preset proportion to the second flexible glass sample in the two-point bending test; applying a constraint on the elastic modulus E to the three-dimensional model of the flexible glass; and applying the constraint to the three-dimensional model of the flexible glass so that the distance D1 between opposite ends of the flexible glass sample in its longitudinal direction is in a preset proportion to the distance D; and obtaining the tensile strength of the flexible glass. The method for testing the tensile strength of flexible glass according to the embodiment of the present invention can effectively test the tensile strength of thin, flexible, and brittle materials such as flexible glass.

The invention relates to the technical field of thin-wall cantilever beams, in particular to a vibration control system and method for a light-driven thin-wall cantilever beam. According to the invention, the elastic piece formed by connecting the LCE fiber in series with the elastic fiber is tightened between the free end and the fixed point of the thin-wall cantilever beam, and the infrared laser or the Fresnel lens is utilized to focus sunlight to emit strip-shaped light to irradiate the LCE fiber, so that a light-driven geometric self-switching mechanism is constructed; the system can drive the LCE fiber to generate periodic deformation under constant illumination, and then automatically switch inside and outside an illumination area through the system configuration change, and finally excite and maintain the self-excited vibration of the thin-wall cantilever beam, and the scheme gets rid of the dependence of a traditional vibration system on an external alternating power supply and a complex control circuit. Light simplification of the system structure and autonomy of energy supply are achieved, the problem of electromagnetic interference is effectively solved, and a new way is provided for design of a cable-free and miniaturized intelligent vibration system.

The present invention relates to the fields of bridge engineering and signal processing technology, and in particular to a method and application for fully automatic cable frequency extraction, order determination, and cable force identification. The present invention first uses a sensor to obtain time-course signals such as acceleration and displacement of cable vibration, and uses Fourier transform and other methods to obtain the spectrum of the vibration signal; then uses a memory-type sieve peak algorithm to search for peaks in the spectrum, that is, the modal frequency of the cable; hash voting is performed on all acquired frequency peaks to obtain the nominal fundamental frequency, and then the order corresponding to all picked frequencies is determined; after obtaining all frequencies and orders, the cable-beam vibration theory can be used to obtain parameters such as cable force. The present invention combines the memory-type sieve peak algorithm and the hash voting statistical algorithm to achieve a fully automatic and intervention-free cable force identification process, and has strong engineering applicability.

This application relates to a wooden main structure, belonging to the field of wooden building technology. It includes a supporting plane positioned between two walls. The supporting plane includes supporting beams, connecting beams, and inclined beams. Several supporting beams are erected between the two walls, and several connectors are evenly and fixedly installed on each supporting beam. Several connecting beams are vertically arranged between adjacent supporting beams, with their ends fixed to the connectors. Several inclined beams are inclinedly arranged between adjacent supporting beams, with their ends fixed to the connectors. A damping pile is fixedly installed at the bottom of each connector, and damping rods are installed between adjacent damping piles. The damping rods are arranged along both the length and width of the supporting plane. This application has the effect of reducing excessive load concentration and beam vibration when a wooden building supports a unidirectional inclined plane, thereby improving its load-bearing capacity and seismic resistance.

The present application belongs to the field of mechanics, and relates to a kind of fast calculation method of nonlinear cantilever beam vibration response, comprising: 1) using Euler-Bernoulli beam theory to establish the transverse vibration equation of nonlinear cantilever beam with fractional order damping;2) using Galerkin discretization method to discretize the transverse vibration equation obtained in step 1), to obtain discrete equation;3) equivalent to the fractional order damping term of discrete equation, and the vibration equation after equivalent is solved iteratively, to obtain the vibration response value of each order mode;4) based on the vibration response value of each order mode calculated in step 3) iteration result, the vibration dynamic response of cantilever beam is calculated.The present application provides a kind of fast calculation method of nonlinear cantilever beam vibration response with low solving difficulty and high solving efficiency.

This invention discloses a noise suppression circuit for a quartz vibrating beam accelerometer. It employs a chopper-AGC closed-loop oscillation circuit to achieve stable driving of the quartz vibrating beam. The circuit includes a chopper amplifier, an AGC automatic control gain module, and a follower amplifier. The electrical signal generated during beam vibration is amplified by the chopper amplifier and low-frequency noise is filtered out, resulting in a noise-reduced signal. This noise-reduced signal is then stabilized by the AGC automatic control gain module and amplified and phase-compensated by the follower amplifier before being fed back to the quartz vibrating beam accelerometer head, forming a stable closed-loop drive. This invention uses chopper modulation technology to modulate the noise signal and input signal to different frequency bands, and uses filtering to separate the noise signal and input signal. This method effectively improves the zero-bias stability and noise performance of the QVBA system.

The invention belongs to the technical field of bridge structure intelligent control, and particularly discloses a bridge vibration active control method and system based on multi-agent cooperation. Comprising the following steps: collecting real-time bridge vibration response data, performing quantitative separation and grading on a bridge vibration response, identifying a dominant mode under a current load, and positioning a part which contributes to vibration most; the bridge vibration response serves as a general target, and the requirement, the control amplitude and the aging requirement of each subtask are packaged into a standard task package; and the subtasks in the task list are specifically allocated by adopting an auction protocol, and the allocation needs to meet the following requirements: the capabilities of the mutually cooperative dampers meet task requirements, and the execution of the subtasks is controlled according to the dependency relationship among the subtasks to ensure that the tasks are completed according to a correct sequence. According to the invention, active, accurate, efficient and adaptive vibration control in a complex vibration coupling environment is realized, and the operation safety, durability and intelligent level of the structure are significantly improved.

This invention discloses an optimized design and intensity noise suppression method for a fiber optic cantilever beam vibration accelerometer with an inclined end face, belonging to the field of fiber optic sensing and vibration measurement technology. It includes sensor optimization design steps and intensity noise suppression steps. In the optimization design step, an analytical relationship model between the optical power transmission coefficient and the input acceleration is established in the main sensing axis direction and the transverse direction. Based on a given acceleration range and key structural parameter range, the influence curves of key structural parameters on key performance parameters are simulated, thereby determining the accelerometer structure. In the intensity noise suppression step, noise suppression is achieved by normalizing the DC component of the vibration acceleration signal of the designed sensor using a noise reduction method based on the DC component normalization of the same optical path. This invention simultaneously achieves high sensitivity, low nonlinearity, and low transverse sensitivity ratio accelerometer design and noise suppression, improving the accuracy and stability of acceleration measurement in complex environments.

The utility model relates to a bridge health monitoring system, and belongs to the technical field of bridge monitoring, and the monitoring system comprises a temperature and humidity sensor which is installed at the outer side of one end of a bridge girder and is used for monitoring the environment temperature and the environment humidity at a bridge location; the wind speed and wind direction sensor is installed in the midspan of the bridge and used for monitoring the environmental wind speed and wind direction at the bridge site; the static level gauge is mounted at the end part of one end of the bridge girder, close to the outer side of the 1 / 4 span and the midspan of one end of the bridge girder, and is used for monitoring the deflection of a girder body; the acceleration sensors are installed on the outer sides of the 1 / 4 span, the midspan and the 3 / 4 span close to one end of the main beam of the bridge and used for monitoring the vibration acceleration of the main beam; the cable force monitoring device is mounted on a midspan suspender and used for monitoring suspender cable force; and the alarm is used for receiving the alarm signal so as to execute a corresponding alarm action. The bridge monitoring device has the beneficial effect that the bridge can be conveniently monitored.

The present application belongs to the field of local resonance beam vibration isolation, and particularly relates to a programmable vibration suppression method and structure based on a local resonance metamaterial beam; the method is electrically connected with a piezoelectric sheet of the local resonance metamaterial beam, the metamaterial beam contains a combination curved beam resonator with four steady state combinations, and the code is composed of the steady state combinations; an elastic wave vibration signal at an excitation end is collected and preprocessed, a dominant frequency is extracted through fast Fourier transform, a control instruction is issued after matching a target code, and the steady state combination of the combination curved beam resonator driven by the piezoelectric sheet is switched to make the metamaterial beam form a band gap matching the dominant frequency. The present application realizes real-time on-demand vibration suppression of elastic waves, solves the problem that a traditional passive vibration isolation system cannot dynamically adjust the vibration isolation characteristics, and is suitable for a dynamically changing external excitation environment, with fast vibration isolation response speed and strong adaptability.

The invention discloses an inter-axis distortion control device of a gantry servo system and a control method of the inter-axis distortion control device, the inter-axis distortion control device comprises a translational motion control unit and a rotary motion control unit, the inter-axis distortion control device further comprises a distortion amount data table, and the position or speed in the translational motion control unit is input into the distortion amount data table; and the distortion amount data table outputs an inter-axle distortion compensation value to the rotary motion control unit and superposes the inter-axle distortion compensation value to an original inter-axle distortion instruction 0, and a new inter-axle distortion instruction is formed and input to the rotary motion control unit. By implementing the motion decoupling control combining the inter-axis distortion compensation value in the distortion data table and the speed change time point, the inter-axis distortion and the vibration of the cross beam can be reduced during acceleration and deceleration, and a gantry servo system with higher speed and higher precision is provided.

A system including a sensor housing including a channel, and cantilever beam connected to the sensor housing and disposed within the channel. The system also includes an actuator connected to the cantilever beam and configured to cause the cantilever beam to vibrate. A sensor is connected to the cantilever beam and is configured to generate a first signal representing a cantilever beam vibration of the cantilever beam. The system also includes an accelerometer connected to at least one of the sensor and the sensor housing, the accelerometer configured to generate a second signal representing an external vibration of the sensor housing. The external vibration changes the cantilever beam vibration. The system also includes a signal processor configured to receive, as input, the first signal and the second signal and to generate, as output, a filtered signal that reduces an effect of the external vibration on the cantilever beam vibration.

The invention provides a construction method and a construction device for a vibration controller of a flexible beam, and solves the technical problem that an existing controller is not ideal for vibration suppression. The method comprises the following steps: forming a flexible beam Hamiltonian dynamic model according to a flexible beam freedom degree characteristic by adopting a Hamiltonian principle; discretizing the Hamiltonian dynamic model of the flexible beam through a hypothesis modal method to form a modal dynamic model of the flexible beam; forming a flexible beam vibration suppression process according to the flexible beam modal dynamics model, and constraining the flexible beam vibration suppression process through a Lyapunov function; and optimizing the controller and the Lyapunov function through the neural network. It is guaranteed that the trajectory of the flexible beam system can be gradually converged to a bounded set from any initial state in the vibration process and is always kept inside, and the consistent final bounded property is met.

The present invention discloses a method for detecting underwater pin-hole alignment, which specifically includes the following steps: (1) obtaining a video of the pin-hole alignment process and performing image preprocessing; (2) obtaining beam vibration frequency data and performing sound feature extraction; (3) using a pre-trained image recognition model and sound recognition model to obtain semantic-level image features and sound features; (4) using a cross-modal alignment model to achieve alignment of image and sound features; (5) using the aligned features for feature fusion and detecting whether the pin-hole alignment is correct through a deep learning model. The present invention adopts a cross-modal network model that can effectively integrate multiple types of data, provide richer and more comprehensive information, and improve the accuracy of underwater identification. The method can assist management personnel in monitoring the site, strengthen the standardization of project management, improve the overall efficiency of the project, and at the same time reduce cost consumption and the probability of accidents and casualties.

The invention discloses a piezoelectric vibration energy collection device based on a zigzag bending root. The piezoelectric vibration energy collection device comprises a vertical zigzag bending root structure, a piezoelectric transducer, a horizontal cantilever beam, a free end mass block and a rectification and voltage stabilization module. The Z-shaped bending root part is folded into a plurality of sections of Z-shaped bending structures along the vertical direction, so that the cantilever beam can be folded for multiple times within a limited length, more piezoelectric transducers can be accommodated, the equivalent modal mass of the cantilever beam can be obviously reduced, the strain distribution uniformity in the piezoelectric transducers can be obviously improved, and the piezoelectric effect of the piezoelectric transducers can be improved. The size of the system is reduced; and the energy output performance is improved. According to the invention, high voltage and power output can be generated, and continuous power supply to the low-power wireless sensing node can be realized. The device is compact in structure, adjustable in frequency and high in energy density, and has potential application prospects in a wireless sensing system powered by vibration energy collection.

The invention discloses a transmission supporting beam damping device which comprises a mounting support, a damping assembly and a fixing assembly, and mounting holes are formed in the two ends of the mounting support; the vibration reduction assembly comprises a limiting ring, an upper vibration reduction soft cushion, a lower vibration reduction soft cushion, a sleeve and a supporting gasket, the limiting ring is arranged on the mounting hole, the inner wall of the bottom of the upper vibration reduction soft cushion abuts against the outer wall of the limiting ring, the lower vibration reduction soft cushion is arranged in the mounting hole, the sleeve is inserted into the mounting hole, the outer wall of the top of the sleeve abuts against the inner wall of the top of the upper vibration reduction soft cushion, and the supporting gasket is arranged in the mounting hole. The supporting gasket is arranged at the bottom of the lower damping cushion; and the fixing assembly is inserted into the sleeve. When a single vibration reduction assembly on the installation support is overturned, one contact point is changed into an upper contact point and a lower contact point, the upper limiting structure and the lower limiting structure participate in stress at the same time, the capacity of resisting overturning in the X direction and the Y direction is improved, extra loads are dispersed, the rigidity of the vibration reduction structure is reduced, and the vibration reduction effect is improved. And the vibration damping performance and the service life of the upper vibration damping cushion and the lower vibration damping cushion are improved.

The utility model discloses a combined type double-outlet single-beam environment-friendly module screen, belongs to the field of vibration mechanical equipment, and particularly relates to a combined type double-outlet single-beam vibration screen. The vibrating screen comprises a shell, a screen box, an embedded vibrating motor, a flexible connector, a spring support, a damper spring, a guide chute, a chassis and a discharge port, a screen frame adopts a single section steel as a supporting main beam, and two sides of the main beam extend to form a bracket; the embedded vibration motors are arranged at the two ends of the main beam, and the lower portion of each spring support is supported by the corresponding damping spring. The two embedded vibration motors are arranged on the two sides of the screen box, main shafts are parallel to each other, the two motor shafts rotate oppositely or reversely, resultant force is perpendicular to the direction of the main shafts of the embedded vibration motors, and the vibration track of the screen box is a straight line. Through the design of the herringbone screen box and modular combination, under the condition of limited height space, the screening area of the vibrating screen is increased, the screening efficiency is improved, and noise and dust hazards in the production process are reduced.

According to the loudspeaker provided by the embodiment of the utility model, the cantilever beam structure is arranged, the cantilever beam structure is connected with the vibrating diaphragm through the connecting structure, the body of the substrate is enclosed to form the cavity, and the orthographic projection part of the cantilever beam on the substrate is located in the cavity, so that when the cantilever beam vibrates, sufficient space can be provided, and the thickness of the substrate is ensured to be uniform in the thickness direction of the substrate. And the cantilever beam can realize large enough deformation or displacement. The vibrating diaphragm is connected with the cantilever beam structure through the connecting structure to form a structure of the cantilever beam and the vibrating diaphragm top cover, so that the effective vibration area can be increased in a three-dimensional space, the chip size can be reduced, and the production cost can be reduced. The distance between the cantilever beams is larger than a set threshold value, so that when the cantilever beams vibrate, the vibration displacement of the cantilever beams can be larger. The cantilever beam is connected with the diaphragm through the connecting structure, and the vibration of the cantilever beam drives the diaphragm to vibrate, so that the vibration displacement of the cantilever beam is large, the displacement of the diaphragm can be increased accordingly, and the sound pressure level output by the loudspeaker is further improved.

The present invention discloses an experimental device for simulating active control of satellite platform vibration and a method for use. A high-strength, low-elasticity rope is used to suspend a cubic satellite model on a rigid frame to achieve horizontal gravity unloading. The exciter is fixed horizontally on the rigid frame and connected to the cubic satellite model through a dual-mode connecting rod. Flexible beams are installed in the centers of both sides of the model, and resistance strain gauges and PVDF films are used as beam vibration sensors. Piezoelectric fiber composite materials are bonded to the surface as vibration control elements. A laser displacement meter is installed on the side of the cubic satellite opposite to the exciter, and the laser displacement meter is fixed to the rigid frame. During operation, the exciter vibrates the cubic satellite model through the connecting rod, driving the flexible beams on both sides to vibrate, and the sensors at the roots of the flexible beams on both sides will have output signals. After the real-time controller collects the sensor output signals, it realizes satellite platform vibration control and flexible beam vibration control through a control algorithm. The present invention has good application prospects in vibration-related technology research and experimental teaching.

The utility model discloses a cross beam vibration suppression damper, a cross beam equipped with the damper and a laser cutting machine, the cross beam vibration suppression damper comprises a plurality of guide rods and balancing weights sleeved on the outer sides of the plurality of guide rods in a sliding mode, and each end of each guide rod is sequentially sleeved with a damping block and a fixing piece. Elastic pieces are arranged between the two sides of the balancing weight and the damping blocks respectively. The cross beam vibration suppression dampers are installed at the two ends of the cross beam, the specifications of all components forming the dampers are adjusted, then the absorption frequency of the dampers is changed so as to adapt to cross beams of different specifications, when the cross beam generates excitation in the horizontal direction, due to the action of the dampers, part of vibration can be absorbed preferentially, and the cross beam vibration suppression effect is improved. Therefore, the vibration of the cross beam is obviously reduced.

This invention provides a method and system for identifying vibration modes of a ship's hull beam based on a wireless mesh network. The method includes: acquiring vibration acceleration signals from multiple measuring points on the hull beam during a preset navigation period; the multiple measuring points are uniformly distributed along the ship's length and symmetrically arranged on both port and starboard sides, and the vibration acceleration signals from these points are obtained through distributed synchronous measurement based on a wireless mesh network; determining the vibration velocity signal corresponding to each measuring point based on the vibration acceleration signals from the multiple measuring points; extracting features from the vibration velocity signal corresponding to each measuring point to determine the velocity spectrum corresponding to each measuring point; and identifying the vibration modes of the hull beam based on the velocity spectrum corresponding to each measuring point and a vibration frequency consistency algorithm to determine the target vibration mode of the hull beam at a target vibration frequency. The solution provided by this invention can achieve convenient, reliable, and high-precision vibration measurement and modal identification of ship's hull beams.

The invention relates to a bridge multi-mode vibration control method and system, and the method comprises the steps: building a suspension bridge space finite element model, and recognizing a key vertical bending mode of a bridge and the frequency and vibration mode of the key vertical bending mode through modal analysis; determining a main beam vibration mode displacement peak value position based on the vibration mode, applying a simple harmonic load consistent with the modal frequency to the main beam vibration mode displacement peak value position, and determining a first speed section damping parameter; selecting seismic waves meeting bridge site conditions as input excitation, and determining a second speed section parameter through nonlinear time-history analysis; and the first speed section parameter and the second speed section parameter are integrally arranged in the longitudinal damper, and the use parameter of the longitudinal damper is switched between the first speed section damping parameter and the second speed section parameter based on the relative speed of the two ends of the longitudinal damper. The single damper can adapt to the vibration characteristics of two working conditions at the same time, and special devices do not need to be installed for vibration in different directions.

The present invention discloses a novel single-beam and double-beam direction-changeable clamp device for vibration experiments, comprising a sleeve base and a clamp shell, wherein a liftable inner shaft is arranged in the sleeve base, and the clamp shell is arranged on the upper end or side wall of the inner shaft by screws, and scissor-type clamps are arranged at both ends of the clamp shell, and a convex plate for placing a workpiece is also provided on the clamp shell, and a movable platform is provided on the convex plate, and a button for controlling the lifting of the movable platform is also provided on the side of the movable platform. The present invention solves the problem of complicated loading and unloading steps of the beam when conducting beam vibration experiments at this stage, realizes the changeable direction, optimizes the loading and unloading of the beam, makes the use process simpler, and can improve work efficiency.

The invention discloses a vibration absorption and isolation device with an additional acoustic black hole combined with a nonlinear arc beam, and relates to the technical field of vibration and noise reduction, the vibration absorption and isolation device comprises a vibration isolation assembly and a vibration absorption assembly, and the vibration isolation assembly is arranged between an excitation source and a controlled structure; comprising a first cover body, a second cover body and a plurality of nonlinear arc beam assemblies which are circumferentially distributed and supported between the first cover body and the second cover body, and the first cover body and the second cover body are fixedly connected to an excitation source and a controlled structure respectively; the vibration absorption assembly comprises at least one additional acoustic black hole structure, the additional acoustic black hole structure can be fixedly arranged between the first cover body and the second cover body, and the additional acoustic black hole structure is arranged among the multiple nonlinear arc beam assemblies in a surrounding mode. According to the vibration absorption and isolation device with the additional acoustic black hole combined with the nonlinear arc beam, a part of vibration energy is isolated through the nonlinear arc beam, a part of vibration energy is dissipated through the energy gathering effect of the additional acoustic black hole and the dynamic vibration absorption principle, and the vibration problem of the structure is reduced.

The present invention discloses a multi-point steady-state excitation system and method for bridge load testing, which relates to the technical field of bridge testing, and includes: a main excitation device, a plurality of auxiliary excitation devices, and a main controller; the main controller is configured to: select a mode to be tested of the bridge main beam; use the main excitation device to excite the bridge main beam at a maximum vibration mode of the mode to be tested at the frequency of the mode to be tested, so that the bridge main beam vibrates at a single frequency; use a plurality of auxiliary excitation devices to excite the bridge main beam at a plurality of maximum vibration modes corresponding to the mode to be tested, and maintain a preset phase difference between the vibration of the inertial mass block of each auxiliary excitation device and the vibration of the bridge main beam at its location; select the next mode to be tested of the bridge main beam, and repeat the process of exciting the bridge main beam vibration until the bridge load test is completed. The present invention can excite the bridge to a significant single-frequency steady-state vibration, and simultaneously achieve the purpose of static load testing and dynamic load testing, requires less excitation equipment, and has high test result accuracy.

This application relates to the field of vibration reduction technology, specifically disclosing a cosine beam vibration damping clamp and a vibration absorption device. The vibration damping clamp includes an inner ring, an outer ring, and multiple annular cosine beams coaxially disposed therebetween. Each annular cosine beam has a different radial dimension, the same number of cosine periods, and is arranged in a staggered manner. They are connected at the crests and troughs by interlayer connectors to form an all-metal elastic energy dissipation structure. The vibration absorption device includes a support fixed to the outer ring of the clamp, on which an acoustic black hole vibration absorption unit composed of a helical black hole beam and an additional mass is integrated. This application uses a pure metal cosine beam configuration instead of rubber, which has the characteristics of high temperature resistance, radiation resistance, and small deformation under large loads. It can achieve quasi-zero stiffness vibration reduction and compression-shear coupling energy dissipation. By utilizing the helical black hole beam to expand the characteristic size in a limited space, the vibration absorption frequency is pushed to below 50Hz. Furthermore, by flexibly tuning the bandgap through replaceable additional masses, the low-frequency line spectrum control capability and engineering versatility are significantly improved.