16 results about "Plate wave" patented technology

The application relates to a kind of active absorption method and equipment of frequency domain filter-based push plate wave generator, and belongs to the field of ocean engineering.The specific process of the method is as follows: a two-dimensional model of active absorption of push plate wave generator is established, and the expression of wave height in front of push plate wave generator is derived.The absorption transfer function of the push plate wave generator of active absorption is derived from the expression of wave height in front of push plate wave generator.The weight distribution combination of all is determined by the target wave to be generated.The error with theoretical displacement under the weight distribution of each combination is calculated by iterative weighted least squares.The optimal solution suitable for the current working condition is determined through error thermal distribution diagram.The application takes the displacement calculated by fitting filter and the theoretical displacement of push plate wave generator as the basis for measuring the effect of active absorption based on weighted iterative least squares, and the optimal filter suitable for target working condition can be automatically fitted through free combination of different frequency bands and weight distribution, without human intervention.

The change in the plate wave shape distribution is evaluated with high accuracy even in the case where vibration is generated on the metal strip. In each of the divided regions obtained by dividing the reflected light region in the plate width direction into j parts, the uppermost position of the upstream side boundary line position of the reflected light region and the uppermost position and the lowermost position of the downstream side boundary line position are found, and for each of the obtained images, the difference between the variation amplitude of the uppermost side boundary line position and the variation amplitude of the lowermost side boundary line position is calculated for each divided region, and is set as information corresponding to the maximum variation amplitude of the reflected light region for the (k)th image, and is made to correspond to the central position in the plate width direction of the divided region i, and when a value indicating the position in the plate width direction is set as a variable x, the position in the plate width direction of the region in the image is normalized to the range of -1 ≤ x ≤ 1 in the plate width range of the region, the value of the information is taken as an index corresponding to the rolling plate wave shape distribution in the plate width direction obtained from the (k)th image, a Chebyshev polynomial is applied to find the coefficients, and the first order coefficient C1' is taken as the detection result signal of the rolling plate wave shape distribution of the first order component in the plate width direction of the (k)th image.

The application provides a vertical multi-plate wave making system with linkage of a rod system and high-precision control and a control method thereof. A computer control system generates a nonlinear wave control signal, and a controller and a driving device are used to independently drive the hinged points on each wave making plate, so that fine adjustment of local movement of the wave making plate is realized, and the vertical velocity and displacement profile of a target wave are highly accurately reproduced by precisely controlling the displacement of each hinged point. Specifically, a transfer function of the swing amplitude of each plate of the vertical multi-plate wave making machine and the wave height is derived by using the ideal fluid potential flow theory of hydrodynamics, the consistent relationship between the swing amplitude of each plate and the ratio of the displacement or velocity of the nonlinear wave vertical distribution, and the geometric invariable characteristics of each wave making plate are combined, and the specific displacement of each hinged point is solved, and then the motion law of the servo motor is obtained according to the geometric nonlinear relationship between the hinged points of the wave making plate and the linkage motion of the servo sliding block, so that the high-precision reproduction of the target wave by the vertical multi-plate wave making system is realized.

The invention relates to an electromagnetic wave absorbing structure, in particular to a three-dimensional circular ring array wave absorbing structure, and belongs to the field of electromagnetic wave absorbing materials. According to the three-dimensional circular ring array wave-absorbing structure, by designing the three-dimensional hollow circular rings, resonance absorption of electromagnetic waves and multiple scattering and path dissipation are increased, meanwhile, the volume ratio of a wave-absorbing medium is reduced, and compared with a traditional flat plate wave-absorbing material, the three-dimensional circular ring array wave-absorbing structure has the advantages of being light in weight, excellent in wave-absorbing performance and the like; the dielectric substrate layer and the three-dimensional circular ring array wave-absorbing layer are integrally formed, compared with an existing three-dimensional structure wave-absorbing body, the wave-absorbing structure is easier to prepare and covered with the wave-transparent protection layer, the overall appearance of the wave-absorbing structure is of a flat plate structure, the low-frequency wave-absorbing performance and the structural stability of the wave-absorbing structure are effectively improved, and the wave-absorbing structure is suitable for the field of wave-absorbing materials.

The application discloses a solid acoustic topology taper connector, comprising a solid acoustic topology insulator, the solid acoustic topology insulator forms at least two different skin depth topology boundary states, and the band gap width of the solid acoustic topology insulator gradually changes along the signal transmission direction.The solid acoustic topology taper connector of the application takes a plate wave phononic crystal as a construction unit, and by designing and skillfully assembling topology boundaries with different mode volumes, the transmission aperture of a solid acoustic wave in the solid acoustic topology taper connector can be switched as required with almost no loss, and a perfect solution is provided for the series / parallel connection of acoustic elements with different sizes; meanwhile, the solid acoustic topology taper connector can be applied to beam shaping, and can convert any irregular or even damaged incidence into desired, regular and rich plane wave output.

The present invention makes it possible to achieve both a wide width between a resonant frequency and an anti-resonant frequency and low spurious. An elastic wave device according to the present invention has a conductor layer and excites plate waves in the SH1 mode. The Euler angles of a piezoelectric body of the elastic wave device are (α) or (β).　(α) (84°–96°, 84°–96°, 21°–45°) or a crystallographic equivalent. (β) (84°–96°, -96°–-84°, -45°–-21°) or a crystallographic equivalent.

The change in the plate wave shape distribution is evaluated with high accuracy even in the case where vibration is generated on the metal strip plate. In each of the divided regions obtained by dividing the reflected light region in the plate width direction into j parts in the obtained image, the most upstream position of the upstream side boundary line position of the reflected light region and the most downstream position of the downstream side boundary line position are found, and with respect to each of the obtained images, the difference between the position data of the most upstream side boundary position and the most downstream side boundary position is calculated for each divided region, the value is set as information corresponding to the maximum rolling direction length of the reflected light region of the kth image, and the information is made to correspond to the central position in the plate width direction of the divided region i. When the value indicating the position in the plate width direction is set as a variable x, the position in the plate width direction of the region in the image is normalized to the range of -1 ≤ x ≤ 1 in the plate width range of the region, the value of the information is taken as an index corresponding to the rolling plate wave shape distribution in the plate width direction obtained from the kth image, a Chebyshev polynomial is applied to find the coefficients, and the first order coefficient C1' is taken as a detection result signal of the rolling plate wave shape distribution of the first order component in the plate width direction of the kth image.

The application discloses a new type of hydraulic driving swing plate wave making device and relates to the field of soil centrifugal simulation test devices. The traditional linear hydraulic wave making device mechanism is prone to problems such as jamming, liquid leakage, wave form transmission distortion and the like when running at high speed under a super gravity field. The application utilizes the natural anti-centrifugal force characteristics of a servo hydraulic swing cylinder, and uses a heavy load cylindrical rod to directly hinge a wave making plate and the hydraulic swing cylinder, thereby simplifying the transmission mechanism, overcoming the non-uniform deformation of the linear hydraulic mechanism and the transmission mechanism under a super gravity field, and overcoming the above-mentioned problems such as the existence of high-order harmonics in wave form transmission. The application has the advantages of stable and reliable mechanism and small deformation, improves the transmission efficiency and service life of the equipment, and can realize high water depth, high frequency and large amplitude wave making under a super gravity field.

A method for calculating surge waves caused by toppling dangerous rock masses, based on wave-making machine theory, targets the most dangerous conditions of a toppling dangerous rock mass. The toppling dangerous rock mass is simplified as a rectangular rigid block, and the maximum surge wave amplitude is assumed to occur during the rock mass's toppling. Using differential theory, a torque balance equation is established for the entire rotational process of the dangerous rock mass. An iterative solution is used to determine the velocity of the toppling dangerous rock mass at any given moment. The toppling process is then simplified to multiple shaking-plate wave-making machines generating regular waves at different times and locations. These regular waves are then superimposed and summed as the surge wave for the toppling dangerous rock mass, ultimately determining the maximum surge amplitude for the toppling dangerous rock mass.

Achieved is an elastic wave device that has a small frequency-temperature dependence and has a wide width between a resonance frequency and an anti-resonance frequency. At least one of a plate wave and a bulk wave is excited. The present invention has: a piezoelectric layer that includes lithium niobate; an IDT electrode; and a dielectric layer that has a positive frequency-temperature coefficient. The Euler angles of the piezoelectric layer are (0°, 30° to 42°, 0°). The result of mathematical expression (1) is 0.60 to 0.75. Mathematical expression (1): Thickness of the piezoelectric layer / (thickness of the piezoelectric layer + thickness of the dielectric layer)

The invention discloses an elastic wave device and a radio frequency front-end module, which can weaken plate waves outside a passband of a surface acoustic wave filter while obtaining a better temperature compensation effect by adjusting the thickness of a temperature compensation layer of the surface acoustic wave filter, thereby improving the out-of-band rejection level of the surface acoustic wave filter and improving the performance of the surface acoustic wave filter. And in the CA state, the influence on the passband performance of other filters in the CA frequency band can be reduced, so that the CA performance is improved.

The present invention provides an electromechanical coupling coefficient K of a vibration mode at a lower phase velocity side than the main vibration in a rotated Y-cut crystal substrate with a rotation angle based on a specific Euler angle. 2 An elastic wave device is disclosed that has a smaller amplitude than a main vibration, has its primary and secondary temperature coefficients substantially set to zero, and furthermore, has a third-order temperature coefficient closer to zero. The device comprises a crystal substrate cut at a rotation angle defined by right-handed Euler angles (φ, θ, Ψ); and at least one comb-shaped excitation electrode that excites a plate wave from the crystal substrate. The crystal substrate is cut at a rotation angle within the range of φ = 0±2°, θ = 17.5° to 19.5°, and Ψ = 0±2°. The plate wave selects a vibration mode with a phase velocity within the range of 3500 to 4000 m / s. When the thickness of the crystal substrate is H and the wavelength of the plate wave is λ, the normalized plate thickness H / λ is set within the range of 1.5 < H / λ < 2.0.

An elastic wave resonator includes: a piezoelectric layer having a groove in a first surface and having piezoelectricity; and a plurality of electrode fingers including a first electrode finger at least partially located in the groove. In a cross-sectional view viewed from the direction in which the plurality of electrode fingers extend, a region of the first electrode finger located within the groove has a wide region and a narrow region having a narrower width than the wide region. The elastic wave resonator excites at least one of a plate wave and a body wave as a main resonance.

The application relates to a preparation method of a patterned copper-plated wave-absorbing honeycomb, and belongs to the field of microwave absorbing materials. The method solves the problems of high weight increase, low printing precision, low design freedom and poor electromagnetic adjustment capability of the existing printed honeycomb. The method comprises the following steps: one, printing; two, glue coating; three, laminating and bonding; four, cutting and stretching; five, copper plating; and six, glue dipping and curing. The application is used for the preparation of the patterned copper-plated wave-absorbing honeycomb.

The invention discloses a push plate wave maker active absorption method and device based on a frequency domain filter, and belongs to the field of ocean engineering. The method specifically comprises the following steps: establishing a two-dimensional model of active absorption of the push plate wave maker, and deducing an expression of the plate front wave height of the push plate wave maker; and deriving an absorption transfer function of the active absorption push plate wave maker according to the expression of the plate front wave height of the push plate wave maker. And determining all weight distribution combinations according to a to-be-generated target wave. And calculating a theoretical displacement error under the weight distribution of each combination by using iterative weighted least squares. And determining an optimal solution suitable for the current working condition through the error thermal distribution diagram. According to the method, on the basis of the weighted iterative least square method, the displacement calculated by the fitting filter and the theoretical displacement of the push plate wave maker serve as the basis for measuring the active absorption effect, the optimal filter suitable for the target working condition can be automatically fitted through free combination of different frequency bands and weight distribution, and human intervention is not needed.

The invention discloses non-uniform-speed wave making equipment based on a bidirectional cam groove and an arc-shaped plate, and belongs to the technical field of wave simulation. The equipment comprises a wave-making water tank and a wave-making device, wherein the wave-making device comprises an arc-shaped wave-making plate and a driving system; the driving system adopts a two-way groove-shaped cam-double crank sliding block composite mechanism, through a double-cam groove with a specific asymmetric outline, constant-speed rotation of a motor is directly converted into non-constant-speed rectangular linear reciprocating motion of a wave making plate, and the dynamic rhythm of'fast-rising and slow-falling 'of natural waves is accurately simulated. Meanwhile, the arc-shaped wave making plate effectively reduces water resistance and energy loss. The problems that a traditional push plate wave maker is single in motion characteristic, distorted in waveform and low in efficiency are solved, dynamic and vivid test waves with high wave surface quality can be generated, and the simulation degree and reliability of a physical model test are remarkably improved.