38 results about "Structural acoustics" patented technology

The invention discloses an artificial structural acoustic field based micro-fluid system which comprises a micro-cavity and an ultrasonic transmitting device. The micro-cavity is used for containing a particle-containing solution, and the ultrasonic transmitting device is used for transmitting ultrasonic waves. The artificial structural acoustic field based micro-fluid system is characterized by further comprising a photonic crystal slab arranged in the micro-cavity, the photonic crystal slab is of an artificial periodic structure and is used for modulating an acoustic field to control particles. The invention further discloses a particle control method for an artificial structural acoustic field based micro-fluid. In the preferred embodiment of the invention, due to the fact that the micro-fluid system comprises the micro-cavity, the ultrasonic transmitting device and the photonic crystal slab, the ultrasonic transmitting device is used for transmitting the ultrasonic waves and the photonic crystal slab is of the artificial periodic structure and is used for modulating the acoustic field to control particles, a new medicine delivery means is provided, and technical support is provided for research and development of drugs.

The invention discloses a method for controlling structural acoustic transmission on the basis of a combined type vibration isolation device. The method includes steps of S1, determining the required combined type vibration isolation device according to parameters of isolated mechanical equipment; S2, vertically placing the isolated mechanical equipment on the combined type vibration isolation device; S3, adjusting the weight of a middle counterweight of the combined type vibration isolation device; S4, adjusting the natural frequency of the combined type vibration isolation device so that the natural frequency of the combined type vibration isolation device is lower than the structural vibration acoustic transmission frequency generated during operation of the isolated mechanical equipment; and S5, fixing the isolated mechanical equipment. The method has the advantages that propagation of noise of high-frequency structure is controlled by a combined type vibration isolation system, the vibration isolation device is arranged between the isolated mechanical equipment and a carrying foundation, performance parameters of upper and lower vibration isolators, a damper and the middle counterweight are matched with one another, the middle counterweight absorbs energy, and the spring and rubber isolators effectively isolate vibration, so that energy transmission of the structural noise is reduced, and the structural acoustic transmission of mechanical vibrating equipment is efficiently isolated.

The invention relates to a prediction module and test method for motor vibration characteristics under a working state, and relates to the technical field of motor structural acoustics. The prediction method and the test method are especially suitable for predictions and tests of the vibration characteristics of various military and civil large motors under the working state. The invention aims at overcoming shortcomings of a conventional prediction and test method, and provides the prediction module for the motor vibration characteristics under the working state. The prediction module goes through the process according to actual conditions of a motor under the working state, can accurately predict the vibration characteristics of the motor under the working state, and is used for carrying out comprehensive and profound researches on the vibration characteristics of the motor under the working state, so that vibration rules of the motor under the working state can be grasped. The invention also provides the test method for the motor vibration characteristics under the working state, tests can be easily and efficiently carried out through the method, the vibration characteristics of the motor under the working state can be really and efficiently obtained, and the method is used for giving guidance for the vibration characteristic tests of the motor under the actual working state.

The invention discloses a method for optimizing reliability of structural noise based on a dimension-by-dimension analysis strategy. The method comprises following steps: firstly, establishing a structural noise optimizing model based on an interval reliability analysis model by using a quantitative structure for a model of interval value and environment and other uncertainties, determining orders and gauss integral points based on least-squares approximation responding to interval parameters by utilizing structural acoustics to response to nonlinearity degree related to interval parameters; secondly, utilizing gauss integral points and a quantitative model for interval numbers to sample parameter vectors of intervals, calculating response vector value at interval parameter sample points, establishing the best square approximation in order to determine the max-minimum point matrix such that response interval vectors can be calculated; and finally, utilizing response interval vectors and safety requirement to calculate reliability in intervals and finishing structural optimization under drive of the optimizing algorithm. The method for optimizing reliability of structural noise based on the dimension-by-dimension analysis strategy has following beneficial effects: by replacing classic safety factor with interval reliability, the method echoes the fine development trend of optimizing structural noise; conservativeness of a conventional optimizing method is effectively avoided; and the method has a broad application prospect.

The invention aims to provide a composite damping supporting plate structure for ships. The invention comprises a supporting plate, a hollow damping mass block, an acoustic absorbent and a band plate, wherein the hollow damping mass block is installed on the supporting plate, the band plate is fixed on the hollow damping mass block, and the acoustic absorbent is installed on the band plate. By utilizing the rigid damping technology, on the premise of no large deformation of the supporting plate structure, the invention obtains favorable effects of damping and noise reduction, and has the functions of damping and sound absorption. On the premise of minimally increasing the weight of the supporting plate, the invention effectively reduces the vibration and acoustic radiation at the power bay section of the ship, has the advantages of higher cost-benefit ratio and high economical efficiency, is a structural acoustic design between double layer hulls suitable for various ships, and has wide application prospects.

The invention discloses a three-dimensional acousto-elastic analysis method of a ship for arbitrary damping processing of a structure and relates to the technical field of acoustics. The method comprises the steps of performing modal analysis on a finite element model of a ship structure with an initial damping laying layer to obtain a modal damping ratio of modalities at various orders of the ship structure; substituting the modal damping ratio of the modalities at various orders of the ship structure into an acousto-elastic coupling dynamic equation of the ship structure to obtain a composite structure dynamic equation of the ship structure; and performing vibration noise analysis on the coupling dynamic equations by use of a three-dimensional acousto-elastic theory of the ship. A damping laying optimization design scheme for the ship structure with structural acoustic radiation as an optimization objective is provided. According to the three-dimensional acousto-elastic analysis method of the ship for arbitrary damping processing of the structure, the direct vibration noise analysis for the laying-damped ship structure is implemented, and the method can be widely used for processing of the damping structure when the vibration noise of the ship is calculated and can provide a technical support for the damping laying design of the ship.

The invention discloses an FE/WSM method for structural acoustic vibration calculation under a Pekeris waveguide, and the method comprises the steps of building an elastic structure acoustic radiationmulti-physical-field coupling model under a local Pekeris waveguide through employing a finite element method, and carrying out the discrete processing of an elastic structure under a three-dimensional Pekeris waveguide; solving each coupling model through a finite difference method, and extracting a structure surface vibration data matrix under the local Pekeris waveguide; adopting a wave superposition method to carry out space optimization distribution of virtual point sound sources in the elastic structure, solving a near-field Green function based on an accurate mirror image source methodof spherical wave decomposition, obtaining a transfer matrix of each virtual source and discrete nodes on the surface of the structure, and solving sound source intensity of each near-field virtual source through inverse operation of vibration data and the transfer matrix; solving a far-field Green function through a simple positive wave disturbance theory, and calculating a monopole matrix fromeach virtual source to a field point; multiplying the sound source intensity by the corresponding single-pole matrix to obtain a sound field; and superposing and summing the sound fields generated bythe discrete virtual sources at the far-field points so as to be equivalent to a radiation sound field of a continuous elastic structure.

The invention belongs to the technical field of structural acoustic radiation prediction, and discloses a high-order gradient smooth meshless processing method and system, a medium and computer equipment, and the method comprises the steps: constructing a mathematic model for calculating the weak meshless coupling DtN boundary of free field structural acoustic radiation through a Galerkin weighting parameter method; softening the rigidity of the numerical model through a high-order gradient smoothing algorithm and reducing a numerical dispersion error by adopting local gradient smoothing under a weak meshless framework; reducing numerical interpolation errors by optimizing a meshless interpolation scheme; verifying the accuracy, stability and practicability of the method through numerical values and tests. According to the method, the weak meshless method coupled with a DtN boundary is analyzed, a numerical method capable of accurately calculating free field structure acoustic radiation is constructed, theoretical and algorithm bases are provided for accurate forecasting of low-frequency noise in a ship structure, the accuracy of low-frequency noise forecasting in the structure is comprehensively improved, and theoretical and technical bases are laid for noise control over ships and warships.

The invention relates to an acoustic attenuation panel (100) which includes the following main elements: a resistive skin (110) having acoustic holes; a solid skin (120); an acoustic structure (130) including a sound-absorbing material and arranged between the resistive skin (110) and the solid skin (120), characterised in that the solid skin (120) is structural and is configured in order to form at least one transverse spacer (121, 122) between the solid skin (120) and the resistive skin (110) of the acoustic attenuation panel (100).

The invention relates to the technical field of air conditioners, and discloses a method, device and equipment for vibration operation analysis of an air conditioner outdoor unit. The method comprises the following steps: under the condition that a hammer made of two or more materials hammers at a set position of the outdoor unit of the air conditioner according to a set transmission path, according to a hammering force signal and a synchronously acquired target point sound signal, obtaining each structural acoustic transfer function corresponding to the materials; according to the correlation of each structural acoustic transfer function, determining the structural acoustic transfer function of the set frequency band as a to-be-spliced transfer function; and performing frequency band splicing on each to-be-spliced transfer function to obtain a structural path transfer function of the set transfer path, and performing vibration noise analysis of the air conditioner outdoor unit according to the structural path transfer function. Therefore, the accuracy of the transfer function is improved, and the vibration noise analysis accuracy of the air conditioner outdoor unit is further improved.

The invention discloses an automobile chassis vibration and noise reduction device based on an acoustic black hole effect, which belongs to the technical field of vibration and noise reduction. The automobile chassis vibration and noise reduction device based on the acoustic black hole effect comprises a plate structure, acoustic black hole structures and a nonlinear energy trap; the plate structure is a part of an automobile chassis; a plurality of acoustic black hole structures are cut on the plate structure; the distance between the upper surface and the lower surface of each acoustic black hole structure is gradually increased from the central axis of the acoustic black hole structure to the outer edge; and the lower portion of each acoustic black hole structure is connected to the nonlinear energy trap. The beneficial effects of the invention are as follows: the automobile chassis vibration and noise reduction device based on the acoustic black hole effect has a simple overall structure, has a good vibration energy gathering effect in the high, medium and low frequency bands, and can realize efficient gathering of vibration energy, which can not only meet the strength requirements of the acoustic black hole structures, but also realize efficient energy gathering and collection, and achieve a good vibration and noise reduction effect.

The present invention provides a deep-water composite structural acoustic array and a sound transmission method based on the array. The acoustic array includes: an axisymmetric cylindrical shell, the axisymmetric shell is composed of an upper shell 6 and a lower shell 5 The shock-isolation and decoupling layer 4 is arranged on the bottom surface of the inner cavity of the axisymmetric cylindrical shell; the front radiation plate 2 is located on the upper layer of the shock-isolation and decoupling layer 4, and is fixedly connected with the element 1; wherein, the element The top of 1 is at a certain distance from the upper surface of the axisymmetric cylindrical shell; the bottom surface of the axisymmetric cylindrical shell is a metal surface. The advantage of the present invention is that, under the premise of ensuring the basic performance of the acoustic matrix, the reliability and service life of the acoustic matrix can be greatly improved, the transmission power capacity of the matrix can be improved, and the hydrostatic pressure resistance of the matrix can be improved, so that The base array can work in deep water environment. The acoustic matrix designed by the invention has great application value in engineering practice.

The invention relates to the technical field of noise reduction headphones, in particular to an active noise reduction algorithm and an active noise reduction headphone; the active noise reduction algorithm comprises an acoustic structure, the acoustic structure comprises a front shell and a rear shell, the front shell is provided with a front cavity, the front shell is further provided with a middle cavity, a hole channel and a leakage hole, and a resonance damping loudspeaker box used for installing a loudspeaker is arranged in the middle cavity; wherein the two hole channels are symmetrically arranged; the front shell is further provided with an annular balance sound channel, and the two hole channels are communicated through the annular balance sound channel. According to the active noise reduction algorithm and the active noise reduction earphone, the consistency of the earphone when being designed and worn by a real person can be improved; meanwhile, the reduction degree of the frequency response range is reduced, and the sensitivity of an earphone loudspeaker can be guaranteed. By means of the active noise reduction algorithm, in the noise reduction performance test process, the FF and FB target curves of two pairs of stereo headphones or four TWS headphones can be obtained at the same time in a non-intrusive noise reduction parameter measurement mode, noise reduction microphone signals do not need to be led out from the headphones for measurement, and signals do not need to be emitted to headphone loudspeakers for measurement either.

The invention discloses a broadband near-seabed deep sea geological structure acoustic detection system and method. The system comprises a mother ship console, an air gun sound source, an underwater sound source towed body, a horizontal sound signal receiving array and a vertical sound signal receiving array. The low-frequency transducer and the high-frequency transducer are combined and installed in a high-low mode to form an underwater sound source towed body close to the seabed, and the underwater sound source towed body is combined with a sea surface air gun sound source to form a three-dimensional broadband sound source. A horizontal sound signal receiving array, a vertical sound signal receiving array and a self-contained hydrophone array located on an underwater sound source towed body are used for receiving broadband sound signals. Compared with a conventional acoustic acquisition method, the system realizes high-penetrability and high-resolution wavelet excitation and multi-angle and multi-direction acoustic signal receiving, is more beneficial to seabed complex structure imaging, and has the advantage of exploration efficiency.