47 results about "Flexural waves" patented technology

Noninvasive method for determining the liquid level and density inside of a container having arbitrary dimension and shape. By generating a flexural acoustic wave in the container shell and measuring the phase difference of the detected flexural wave from that of the originally generated wave a small distance from the generated wave, while moving the generation and detection means through the liquid / vapor interface, this interface can be detected. Both the wave generation and wave detection may be achieved by transducers on the surface of the container. A change in the phase difference over the outer surface of the vessel signifies that a liquid / vapor interface has been crossed, while the magnitude of the phase difference can be related to fluid density immediately opposite the measurement position on the surface of the vessel.

An apparatus and method for determining fast and slow shear wave velocities and orientations in an anisotropic earth formation that reduces the error and ambiguity in calculating these parameters and eliminates the need for dipole receivers and multiple dipole sources. The apparatus generally includes a single dipole source capable of generating an acoustic signal within a borehole. The acoustic logging tool contains multiple levels of receivers. At each level, four receivers, which may be conventional pressure transducers, receive shear / flexural wave signals which propagate along the borehole earth formation. These receivers measure the pressure fields from the wave signals. A processing device, preferably a UNIX(TM) based computer, interpolates the measured pressure fields between any two adjacent receivers. The processing device performs cross-component decomposition on the pressure field to determine shear wave orientation and velocity. Using the shear wave orientation and velocity the processing device determines transit time anisotropy, energy anisotropy, and slowness anisotropy.

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).

A loudspeaker drive unit comprising a resonant acoustic radiator, an exciter on the radiator to apply bending wave energy to the radiator to cause it to resonate, a support for the loudspeaker drive unit, and means resiliently coupling the exciter to the support.

A system for exciting flexural waves on an optical fiber (102) is provided. The system includes a substrate (114, 118), an actuator (106), and a mechanical optical fiber coupling (104). The actuator is formed of an electromechanical transducer material. The actuator is mounted on the substrate. The mechanical optical fiber coupling (for example, an adhesive media) forms a secure mechanical connection between the actuator and the optical fiber. The mechanical optical fiber coupling is configured for communicating mechanical vibrations from the actuator to the optical fiber. However, it should be understood that the mechanical optical fiber coupling is exclusive of a tapered horn.

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 invention is used in the field of oil field logging technology, mainly resolving the defect of existent earth stress detection technology which has not any one non-destructive examination method. Said invention is characterized by that it includes the following steps: making cross dipole array acoustic log data undergo the process of angle rotation treatment, then obtaining two main time sequences, on said basis extracting flexural wave dispersion curves of two principal directions, utilizing data of n frequency points on the flexural wave dispersion curves of two principal polarization directions to create n equalities according to two formulae, in which said formulae can be obtained by inversion of well mode wave acoustic elastic equation, in which n is greater than or equal to 6, and atilizing resolution of sain n equalities so as to can obtain maximum main stress SH and minimum main stress Sh of formation.

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.

Cased-hole radial profiling of shear parameters from sonic measurements is disclosed. Example methods disclosed herein include determining a variation of a first shear modulus at a first radial position from a cased borehole in a formation based on a first weighted average of fractional variations of Stoneley wave velocities for different wavenumbers, the first weighted average based on first weights determined using a perturbation model including parameters to model the borehole casing, and determining variations of second and third shear moduli at respective second and third radial positions from the borehole based on second and third weighted averages of fractional variations of respective first and second flexural wave velocities for different wavenumbers, the first and second flexural wave velocities associated with respective first and second orthogonal borehole axial planes of the formation, the second and third weighted averages based on respective second and third weights determined using the perturbation model.

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.

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.

The present invention relates to a method for selecting sound source frequency, used in the cased-hole dipole shear wave acoustic log. Said invention is characterized by that said method includes the following steps: firstly, utilizing acoustic moveout curve to give out compressional wave velocity of said well: then utilizing velocity field equation under the column coordinate and boundarg connection condition under the condition of cased-hole and adopting three-dimensional velocity-stress finite difference method to numerically simulate the dipole acoustic all-wave wave field of oil-water well, then utilizing the quick and slow flexural waves obtained by means of numerical simulation under the condition of that the circumference of cased-hole has abonormal stress to make dispersion analysis; then utilizing the freguency of cross point of quick and slow flexural waves to define main frequency of sound source.

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 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.

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.

The invention discloses a method for measuring a material loss factor, which belongs to the measuring field of material damping characteristics. The method comprises the following steps of preparing two metal plates with same sizes and with same materials, laying one layer of materials to be measured on one metal plate so as to form a composite damping plate, measuring to obtain flexural wave propagation speeds of the composite damping plate and the metal plate at different impulse signal frequencies, calculating the Young modulus ratio e of a damping layer to a metal layer, measuring to obtain a loss factor beta of the composite damping plate structure, and then calculating to obtain the material loss factor eta of the damping layer. The method has the beneficial effects that the measurement of the structure loss factor and the flexural vibration wave speed is combined, so as to measure a self material loss factor of a multi-cavity damping material and overcome the defects on test of the multi-cavity damping material with soft texture and damping effect by other measuring methods, and therefore, the method has a certain engineering value and a broad application prospect.

The present invention provides a method and a device for determining a shear-wave attenuation factor in multi-pole array acoustic logging. The method comprises the following steps: acquiring multi-pole array acoustic logging data of a target stratum; according to the multi-pole array acoustic logging data of the target stratum, determining a corresponding flexural-wave attenuation factor; and determining the shear-wave attenuation factor at preset frequency by applying the flexural-wave attenuation factor, and evaluating the target stratum according to the shear-wave attenuation factor. By theadoption of the method provided by the invention, the shear-wave attenuation factor in multi-pole array acoustic logging can be effectively and accurately acquired, and then the evaluating accuracy of a target reservoir as well as the accuracy and the reliability of a reservoir exploration-development scheme can be effectively improved.

An acoustic glass breakage detector including a pulsating current-powered microphone and operable for generating pulsed signal data corresponding to sound waves detected thereby, a sample and hold circuit operable for converting the pulsed signal data into a voltage level signal and storing the voltage level signal, a sound frequency band pass amplifier operable for ascertaining whether the voltage level signal corresponds to an explosion-like sound typical of an initial glass-breakage sound, a flex wave band pass amplifier operable for ascertaining whether the voltage level signal corresponds to a flex wave typical of an initial glass-breakage sound, and circuitry operable, responsive to ascertaining that the voltage level signal corresponds to an explosion-like sound typical of an initial glass-breakage event and that the voltage level signal corresponds to a flex wave typical of an initial glass-breakage sound, for ascertaining that the pulsed signal data is indicative of a glass-breakage event.

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 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.

Methods are disclosed for evaluating a material on a remote side of a partition separating first and second domains wherein flexural waves within the partition are received by spaced-apart ultrasonic receivers and processed to determine the velocity of the waves propagating into the second domain from a first receiver to a second receiver located more remote from the transmitter than the first receiver and whose separation from the first receiver is known. Comparison of a theoretical phase velocity with the measured phase velocity of the recorded waves allows determination as to whether the flexural wave is propagating through solid. This may be based on a measurable deviation between the two curves occurring at a critical frequency, which may be identified by a perturbation in a group velocity plot. Discrimination may also be based on the gradient of a straight line that best-fits the attention dispersion of the frequency spectrum.

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.

The invention proposes an all-fiber acousto-optic frequency shifter and an all-fiber heterodyne measurement system applying the all-fiber acousto-optic frequency shifter, wherein the all-fiber acousto-optic frequency shifter includes a Bragg grating fiber, an aluminum cone and piezoelectric ceramics, the piezoelectric ceramics is fixedly adhered on the bottom plane of the aluminum cone, there is an angle in a range of 1.11 degrees to 1.15 degrees between the top plane and the bottom plane of the aluminum cone, and the top plane of the aluminum cone is vertically adhered on an end face of the Bragg grating fiber. A reflectance spectrum of the all-fiber acousto-optic frequency shifter changes with respect to a reflectance spectrum of an all-fiber acousto-optic frequency shifter under the action of an existing typical acoustic wave of a transverse flexural wave or an acoustic wave of a longitudinal wave, so that the all-fiber acousto-optic frequency shifter has higher reflectivity with the same driving power. The manufacturing cost of the all-fiber acousto-optic frequency shifter is reduced, while the power consumption is reduced, so that problems of a complicated structure, low coupling efficiency and a small modulation range and other problems of an existing all-fiber acousto-optic frequency shifter are solved.