46 results about "Flexural waves" patented technology

Arrangement of a sound reproduction system (1), including at least one input (2), a sound field generator (4), a loudspeaker panel (10); the at least one input (2) connected to the sound field generator (4), and the sound field generator (4) connected to the loudspeaker panel (10); the at least one input (2) arranged for generating an audio signal; the sound field generator (4) including a wave field synthesizer (6) arranged for generating a spatially perceptible sound field for the audio signal and for outputting the spatially perceptible sound field to the loudspeaker panel (10), the loudspeaker panel (10) being a multi-exciter Distributed Mode Loudspeaker panel (10) consisting of a plate (12) and a plurality of transducers (16), arranged within an array (14) on the large plate (12) for reproducing the spatially perceptible sound field from the wave field synthesizer (6) by exciting bending waves in the plate (12).

Acoustic devices have members extending transversely of thickness and capable of sustaining bending waves causing consequential acoustic action by reason of areal distribution of resonant modes of natural bending wave vibration consonant with required achievable acoustic action of said member over a desired operative acoustic frequency range, Areal distribution of stiffness including variation(s) therein is used to get desired locations for bending wave transducers and / or good resonant mode acoustic action from inherently unfavourable shapes of members. Members with combined pistonic active drive and bending wave excitement at centers of mass and geometry are featured.

Acoustic devices have members extending transversely of thickness and capable of sustaining bending waves causing consequential acoustic action by reason of areal distribution of resonant modes of natural bending wave vibration consonant with required achievable acoustic action of said member over a desired operative acoustic frequency range. Areal distribution of stiffness including variation(s) therein is used to get desired locations for bending wave transducers and / or good resonant mode acoustic action from inherently unfavorable shapes of members. Members with combined pistonic action drive and bending wave excitement at centers of mass and geometry are featured.

A door leaf includes a stiff, light structural part that maintains fed-in vibrational energy and, by flexural waves, propagates this energy in at least one active surface perpendicular to its thickness to distribute resonance mode vibration components over at least one surface, which has specified, preferred locations or sites within it for transducer devices, which are affixed on the structural part at one of the locations or sites to set the structural part into vibration and to allow it to resonate, thus creating an acoustic radiator that delivers an acoustic output signal when it vibrates in resonance, the front and / or the rear cover panel of the door leaf being part of the stiff, light structural component. The transducer(s) is / are situated between the cover panels. This arrangement provides a door with a loudspeaker function, which needs no extra volume compared to an ordinary door, and which is able to provide sound reliably and comprehensively to one or more rooms, which adjoin this door acting as a loudspeaker. Advantageously, additional loudspeakers or loudspeaker boxes are not required in a room that receives sound by this door with loudspeakers.

The present invention relates to a subway tunnel segment service performance detection method based on wave velocity determination. According to the method, on the basis of hollow tubular structure modality dispersion analysis based on a thin-walled shell theory, propagation laws and propagation velocities of various elastic waves in a tubular structure are determined; a wired testing system is adopted or a wired testing system is matched with an internet-of-things technology to reasonably set an acceleration and a velocity sensor; and vibration signals are dynamically collected through specific hammer and other pulse wave excitation manners, and frequency phase characteristics of the signals are determined through HHT (Hilbert-Huang transformation) and other signal post-treatment manners so as to extract wave velocities of specific bending waves and compression waves to determine a structure service performance between various detection points.

The invention relates to an additional eccentric acoustic black hole vibration reduction structure, and in a uniform area, namely a cylindrical area, of the vibration reduction structure, the propagation speed and wavelength of waves with a certain frequency are not changed. However, at an acoustic black hole part, the propagation speed of the wave is reduced along with the reduction of the thickness; the wavelength is reduced, the vibration amplitude of waves is increased and is gathered toward an area with reduced thickness, when the waves arrive at the cut-off position, due to the fact thatthe vibration reduction structure is provided with an acoustic black hole extending part, namely a first annular part, bending waves continue to be propagated at the wavelet speed, the weak-structureposition occurs at the outermost end of the structure, the deformation of the outer end is easier, the acoustic black hole effect is easier to occur, and the high-efficiency broadband vibration reduction and noise reduction are achieved.

The invention provides a focusing vortex acoustic tweezers control system and a method with an obstacle avoidance control function. The active phase control and passive structure phase modulation of aplanar fan-shaped transducer array are utilized to construct the focusing vortex acoustic tweezers with a controllable obstacle avoidance cavity, and object control behind an obstacle is realized. The curvature radius of a self-bending wave beam arc track is regulated and controlled through the order and the wave number of a semi-Bessel sound beam, the hollow radius of a phase modulation disc isdetermined according to the size of an obstacle, and regulation and control over the shape and the size of an arc track obstacle avoidance cavity and the axial distance of the acoustic tweezers are achieved. The capture radius and the capture capability of the focusing vortex acoustic tweezers are further regulated and controlled through the vortex topological charge of the transducer. According to the invention, sound waves emitted by the transducer array can be guided to bypass bones and important organs to form the focusing vortex acoustic tweezers, rotary capture of drug particles is realized, the thermal therapy effect of a focal region can be enhanced by utilizing drug accumulation, and a new method is provided for application of the focusing vortex acoustic tweezers in biomedicine.

In some embodiments, apparatus and systems, as well as methods, may operate to record a plurality of acoustic waveforms corresponding to acoustic waves received at azimuthally orthogonal dipole receiver arrays surrounded by a geological formation, the waves being generated by azimuthally orthogonal transmitter arrays. Further activity may include analytically estimating a global minimum of a predefined objective function with respect to an azimuth angle at a point in an auxiliary parameter space associated with a set of auxiliary parameters, minimizing the objective function at the analytically estimated angle with respect to the auxiliary parameters, removing existing ambiguities associated with the fast and slow principal flexural wave axes, and determining at least one property of the geological formation based on the global minimum. Additional apparatus, systems, and methods are disclosed.

Disclosed is an apparatus or a method for measuring flexural waves and / or vibrations acting on ferromagnetic materials or ferromagnetic films. The present invention includes a bias magnet disposed around the ferromagnetic material so as to form a magnetic field in accordance with a stress distribution pattern occurring as the flexural wave propagates along the above said ferromagnetic material, and a measuring device for measuring the time-varying change of the magnetic induction resulting from the propagation of flexural waves on the ferromagnetic material. In addition to the above components, the bias yoke can be disposed around the ferromagnetic material to support the function of the magnet and the formation of the magnetic circuit as a measuring device for the change of the magnetic induction. In addition, a fixed electromagnet can be used as the bias magnet.

A speaker cone is provided that contains a base portion, and the base portion has a front end and a rear end. The front end contains a plurality of discontinuities such that a first distance from a reference point on a longitudinal axis of the base portion to a first point on the front end is different than a second distance from the reference point to a second point on the front end. By creating the plurality of discontinuities in the front end of the base portion, the distortion or reduction in the amplitude of a flexural wave generated by the speaker cone is dramatically reduced.

A robust tag. The robust tag may include a body section, at least one movable latching member disposed within the body section, at least one attachment structure receivable within the body and selectively engageable to the at least one latching member; and at least one responsive member disposed within the body and in cooperative arrangement with the at least one latching member. Upon the application of a signal to at least one drive position on the body section, the responsive member generates a flexural wave that induces a movement of the at least one latching member, so as to disengage the at least one latching member from the at least one attachment structure.

A touch-sensitive interface has a contact surface that is able to be touched by an effector (e.g., a finger). The interface includes actuating transducers (e.g., piezoelectric transducers) allowing a standing flexural wave to be formed, in a resonant mode, extending over the length of the slab. The interface includes a detector for measuring the amplitude of the wave, and a detecting circuit for determining an attenuation signal, when the contact surface is touched by an effector. It includes a processing circuit for estimating a magnitude of the force exerted by the effector on the contact surface.

The present invention provides an acoustic wave sensing device integrating a micro-channel, its manufacturing method and an acoustic wave sensor. The method uses a piezoelectric block as a substrate, and uses electromechanical or chemical processing to make its sensing area into a piezoelectric sensor. The electric thin plate, and then use the interdigitated electrode structure (Inter-digital transducer, IDT) to make it generate flat plate flexure waves. In the present invention, the microfluidic channel can be further integrated on the same substrate with piezoelectric properties by the same processing method or bonding method. The present invention utilizes new element manufacturing and design to produce elements with good piezoelectric characteristics, stable temperature compensation characteristics and firm structure, which will enable flat plate flexural waves to be applied to liquid state sensors. Therefore, the present invention can solve the problems of existing acoustic wave sensing devices such as poor piezoelectric characteristics and poor film structure.

A vehicle windscreen accessory comprising a body member, an adjustable support structure for the body member whereby the position of the body member can be adjusted, the body member comprising a mirror member and a loudspeaker having a bending wave panel-form acoustic member, the mirror member and panel-form member being integral.

The invention discloses a method for automatically adjusting a dipole sound source in acoustic logging based on segmental linear frequency modulation. The method includes the following steps: sending an excitation signal to the logging formation, receiving a corresponding echo signal, and extracting the echo signal from the echo signal. The bending wave signal; process the bending wave signal to obtain the corresponding spectrum curve; obtain the three amplitudes under different frequency bands in the spectrum curve; obtain the duration corresponding to the three amplitudes respectively; increase the duration corresponding to the maximum amplitude value, and decrease The duration corresponding to the minimum amplitude value; according to the adjusted three durations, a new excitation signal is determined. Starting from the actual needs of downhole operations, adaptive parameters can be adjusted according to changes in the downhole environment, so as to ensure that the signal adapts to the changing downhole geological environment.