38 results about "Structural acoustics" patented technology

The present invention relates to an apparatus for producing spunbonded nonwoven fabrics. The molten polymer fed into the spinning beam from the melt source is extruded through a plurality of linearly arranged spinneret holes into monofilaments arranged in a curtain shape. A pulling force is applied to the monofilament by means of a pulling nozzle. The monofilaments are then deposited on a conveyor belt where they form a spunbond nonwoven fabric. A monitoring device is arranged on the pulling nozzle, which measures characteristic values ​​characterizing the machining process. One or more structure-borne sound sensors are preferably used as monitoring means. The measurement results of the monitoring device are compared with setpoint values ​​and fed to a signaling device or used to regulate the machining process.

The invention discloses a phonon function material structure containing non-convex type section holes and a making method thereof. The phonon function material structure comprises non-convex type section holes arranged periodically and is characterized in that the non-convex type section holes are formed by bulging one rectangle from the surrounding of the center of each edge of a square hole to the center of the square hole, and all edges are not mutually crossed; relative size of a non-convex section is calculated according to the requirements for structural strength and porosity (less than 50 percent); proper lattice constants are determined according to the requirement for structure acoustic characteristics; and on the basis, holes are punched in a required matrix material, symmetry of the non-convex section holes is regulated to ensure that the non-convex section holes are densely distributed in the structural cycle direction, therefore, the purpose of obtaining the phonon function material structure with a widest acoustic band gap is achieved. The invention has the advantages that the widest acoustic band gap is obtained while the requirements for the structural strength and the acoustic characteristics are met, and the phonon function material structure only comprises the non-convex section holes distributed periodically and is simple in process.

The invention discloses a towed deep seabed shallow structure acoustic detection system and method, belonging to the field of seabed exploration. The system includes a mothership console and a towing body. The mothership console is connected to the towing body through a photoelectric composite cable. The echo hydrophones are placed near the seabed, and the hydrophones are evenly arranged around the bottom of the drag body to collect echo signals; the sound source of the transducer adopts a sound source system combining high frequency and low frequency, and the low frequency transducer The sound source is placed above the high-frequency transducer. The combination of different frequency sound sources can ensure the acquisition of broadband signals and achieve the dual goals of high resolution and high penetration depth. It can be further applied to seabed bottom identification and deeper bottom layers. Synchronous detection of cracks.

A system for particle manipulation and sorting based on structural acoustic field comprises a sample holder, an ultrasound transmission device and an artificial structure, the sample holder is used to place particles to be sorted, the ultrasound transmission device is used to transmit ultrasound wave, the artificial structure is periodic structure used to modulate acoustic field to produce stronger acoustic radiation force and sort the particles to be sorted. And there is a method for particle manipulation and sorting based on structural acoustic field. Due to the sample holder, the ultrasound transmission device and the artificial structure, plurality of particles could be placed on the sample holder simultaneously, the artificial structure is used to modulate the acoustic field to produce stronger acoustic radiation force, trapping the specific particles under the lower surface of the artificial structure at the same time, realizing rapid, batch sorting and increasing the efficiency.

The invention relates to a test method for identification of motor damping characteristics, which belongs to the field of structural acoustic design of motors, and is especially suitable for experimental research on the damping characteristics of various large-scale motors for military and civilian use, and can be used as a reference basis for simulation calculations to guide the vibration and noise response of motors calculate. The purpose of the present invention is to make up for the shortcomings of the existing motor damping characteristic identification method, overcome the defects of the traditional motor damping setting, and provide a test method for motor damping characteristic identification. Obtain different assembly structures of the motor through disassembly and assembly, build a vibration exciter response test platform, use the electromagnetic exciter to generate an exciting force with a given amplitude and frequency using closed-loop control, test its vibration response, and pass the excitation-response test results Obtain the damping characteristics of different assembly structures of the motor, as a reference for subsequent simulation calculations, guide the calculation of the vibration response of the motor, and greatly improve the accuracy of the calculation model.

An adjustable acoustic metamaterial barrier system for transformer noise spatial distribution characteristics comprises an acoustic metamaterial barrier (3) and a noise measurement and analysis system(2). The acoustic metamaterial barrier (3) is composed of a metamaterial support bracket (7) and a fractal structural acoustic metamaterial module (8). The metamaterial support bracket (7) is parallel to a transformer sound source surface (1). The fractal structure acoustic metamaterial module (8) is embedded in the metamaterial support bracket (4). The noise measurement and analysis system (2) measures the noise in the range of the acoustic metamaterial barrier (3), and obtains the spatial distribution characteristics of the noise. According to the spatial distribution characteristics of noise, fractal structural acoustic metamaterial modules (8) with different parameters are selected. As that acoustic wave is transmit to the acoustic metamaterial barrier (3), since the parameters of theacoustic metamaterial module (8) are selected according to the noise distribution characteristics of the corresponding position, the noise amplitude of the target noise reduction region can be greatly reduced.