83 results about "Torsional wave" patented technology

A method and apparatus for implementing magnetostrictive sensor techniques for the nondestructive evaluation of pipes or tubes. A magnetostrictive sensor generates guided waves in a pipe or tube, which waves travel therethrough in a direction parallel to the longitudinal axis of the pipe or tube. This is achieved by using a magnetized ferromagnetic strip being pressed circumferentially against the pipe or tube. For improved efficiency, the strip may be made from an iron-cobalt alloy. The guided waves are generated in the strip and coupled to the pipe or tube and propagate along the length of said pipe or tube. For detection, the guided waves in the pipe or tube are coupled to the thin ferromagnetic strip and are detected by receiving MsS coils. Reflected guided waves may represent defects in the pipe or tube.

Apparatuses, methods, and systems are described which assist in controlling toolface orientation of a bottom hole assembly. A controller instructs a top drive to oscillate a drill string an oscillation revolution amount to reduce friction of the drill string in a wellbore during a slide drilling procedure. A torque sensor detects torque at an interface between the drill string and the top drive, and the controller determines properties of a torsional wave from the detected torque that is propagating along the drill string during the slide drilling procedure. The controller determines a modification to the oscillation revolution amount and / or rotations per minute in order to control the toolface orientation in a desired manner. The top drive implements the determined modification and thereby assists in controlling the toolface orientation during the slide drilling procedure.

A device to detect defects of magnetic conducting structures based on magnetoconstriction torsional waves belongs to an ultrasonic nondestructive detector, which overcomes shortcomings of high guide wave attenuation of vertical mode and remarkable frequency dispersion effect. During detection, it is unnecessary to process surfaces of the structure. The present invention comprises a pulse signal generator, a power amplifier, a magnetoconstriction torsional wave sensor, a signal preprocessor, an A / D converter and a computer. Wherein, the magnetoconstriction torsional wave sensor is composed of an excitation unit and a receiving unit. The computer controls generation of pulse signals. The pulse signal is amplified by the power amplifier and then generates torsional waves in the structure through the excitation unit. The receiving unit receives the torsional wave from the structure, which is processed by the signal preprocessor and then converted into digital signals by the A / D converter. The computer obtains defect information of the structure. The present invention can conveniently excite and receive torsional waves, detect defects along axis of the structure and adapt to long-distance detection of clad pipes and cables with PE jacket.

The present invention relates to a method and an apparatus for structural diagnosis, which generates torsional waves upon a shaft, beam or pipe having arbitrary cross-sections, such as a circular cross-section, and senses existence or location of the cracks through analyzing reflected waves. The present invention provides a magnetostrictive transducer comprising a plurality of ferromagnetic strips attached, around circumference of a member having an arbitrary cross-section with a fixed inclination; a first housing disposed to surround the ferromagnetic strips, the first housing being made of insulating material; and a coil wound around the first housing. The magnetostrictive transducer according to the present invention can generate torsional waves upon a member when a current is supplied to the coil, and can measure reflected torsional waves. Further, the present invention provides an apparatus and a method for structural diagnosis using the magnetostrictive transducer.

Disclosed is an electromagnetic torsional split-Hopkinson bar loading device, which comprises power supplies, an electric energy storing and releasing device, and a torsional gun. The torsional gun communicates with the electric energy storing and releasing device via conducting wires, and the electric energy storing and releasing device communicates with power supplies. The electric energy storing and releasing device is used for supplying an instantaneous strong current to a stator coil of the torsional gun, so that the stator coil generates electromagnetic force to a rotator on a permanent magnet, and the rotator is allowed to rotate to generate an instantaneous torque. The torsional gun is composed of the stator and the rotator, generates the instantaneous torque, converts the instantaneous torque into a torsional wave, and outputs the torsional wave to a torsional split-Hopkinson bar via a rotor shaft. The amplitude of a torsional stress actually generated is controlled via the charging voltage of the electric energy storing and releasing device, and the width of a torsional stress wave actually generated is controlled by adjusting the capacitance of the electric energy storing and releasing device. A conventional torsional split-Hopkinson bar sample is adopted, and torsion loading of a material can be performed at an anticipated pulse amplitude and pulse width. The whole device is simple to operate and has strong controllability.

The invention relates to a magnetostrictive displacement sensor with high precision and large measuring range, which mainly comprises a waveguide tube and a sensing electronic head. The waveguide tube is used for generating an echoed signal, receiving an exciting pulse signal, simultaneously generating magnetostrictive effect at the position of a magnetic ring, and generating magnetic torsional wave to be returned to an echo acquisition processing analysis system; the waveguide tube is sleeved with the magnetic ring of a permanent magnet; and the directions of a magnetic field generated by the magnetic ring and a magnetic field generated by the waveguide tube are different, and once the magnetic fields are crossed, the magnetic torsional wave is generated. The sensing electronic head comprises five subsystems, namely a control unit, an exciting signal generating system, a communication system, a power supply circuit and the echo acquisition processing analysis system. The magnetostrictive displacement sensor has the advantages that a stable signal exciting and high-speed data acquisition system is designed, and the anti-jamming design of the signals is enhanced; the application range of the sensor is improved; and the measuring precision is quite high, the measuring range is large, the measuring distance is between 25 and 18,000 millimeters, and simultaneously data measured in long distance can be processed through a Zigbee wireless mode.

The present invention discloses a magnetoconstriction type displacement sensor which measures the displacement by using a time-difference displacement measuring method. A torsional wave is generated by crossing two different magnetic field and then the transmitting time of the torsional wave is computed, thus the displacement measuring can be performed indirectly and accurately. The magnetoconstriction type displacement sensor consists of a center control unit, a drive signal generator, a signal processing circuit, a high-speed timing circuit, a RS485 interface circuit, a power supply circuit and the wave guide filament.

A method and apparatus for generating and measuring a torsional wave in a rod, shaft or pipe using magnetostriction are provided. The magnetostrictive transducer includes at least one strip attached to a predetermined position of a rod member, an insulator disposed around the strip, a coil wound around the insulator, and magnets providing a bias magnetic field to the strip, wherein a plurality of strips are attached to the rod member at predetermined intervals in a circumferential direction, and one pole of the magnet is close to an end of a first strip among the plurality of strips, and another pole of the magnet is close to an end of a second strip among the plurality of strips.

The invention discloses a mining intrinsically safe multi-point displacement meter with magnetic anchor heads and a magnetostrictive line as displacement sensors. The mining intrinsically safe multi-point displacement meter is structurally composed of the magnetic anchor heads, a flexible measuring bar, an instrument cabin, an echo energy change detection device, magnetostrictive line supporting blocks and an end fixing device, the magnetostrictive line is arranged in the flexible measuring bar, the magnetic anchor heads are fixed to a mine tunnel roof rock layer, a processor sends an electric pulse to the magnetostrictive line through a drive circuit, the electric pulse and the magnetic anchor heads interact to form torsional waves and longitudinal waves, the electric pulse spreads in the magnetostrictive line, the arrival time of an echo wave is detected through the echo energy change detection device, and the roof displacement of the positions of the magnetic anchor heads can be calculated. Compared with a multi-point displacement meter with four to six measuring ropes, the number of multi-point displacement ropes in the same drilled hole of the mine tunnel roof rock layer can be reduced, and the problem that the multi-point displacement ropes in the same drilled hole are complex in mounting and prone to being wound is effectively solved.

Methods and apparatus for transmitting power and data along a metal pipe using wideband acoustic waves. Arrangements use shear-horizontal waves, transmitting narrowband signals for power applications and wideband signals for communications having a bandwidth greater than the coherence bandwidth of the acoustic-electric channel. Chirp wave signals, direct sequence spread signals, and on-off keying are used. Acoustic-electric channels include wedges fixed to a pipe or other substrate, transducers fixed to the wedges, and electronics linked to each transducer for sending and receiving power and signals. Matching networks, rectification circuits, and non-coherent signal reception methods may be used.

The invention relates to a loading device for a disc type split-hopkinson torsional bar based on electromagnetic force and an experimental method. In the loading device, an anode and a cathode of a power supply are respectively connected with an anode input end and a cathode input end of an electric energy storage and releasing device through wires; and an anode output end and a cathode output end of the electric energy storage and releasing device are respectively connected with the anode input end and the cathode input end of a torsion gun through wires. The loading device provided by the invention utilizes the electromagnetic energy-mechanical energy conversion principle to generate an instant electromagnetic torque in an electric control manner, utilizes a mechanical structure to convert the torque into torsional wave and is applied to the experiment of the split-hopkinson torsional bar. The electric control mode is adopted, so that the generation time of stress wave of the electromagnetic type split-hopkinson torsional bar shows unique superiority. An electronic switch is adopted for strictly controlling the generation time of the stress wave, so that the synchronism problem under a complex loading mode is solved.

The invention discloses a piezoelectric transduction type magnetostrictive sensor used for liquid level (displacement) measurement and a piezoelectric type torsional wave transducer thereof. The piezoelectric type torsional wave transducer comprises a waveguide wire, the output section of the waveguide wire is provided with an amplification rod, and the ends of the amplification rod are connectedwith piezoelectric elements. After a torsional wave signal is transmitted to the amplification rod through the waveguide wire and is amplified, the torsional wave signal is converted into an electricsignal and output. A normal line of each piezoelectric element is vertical to the waveguide wire and the amplification rod. The amplification rod converts circumferential torsional waves transmitted by the waveguide wire into distortion approximate to a linear direction on the normal line of each piezoelectric element so as to act on the piezoelectric elements to generate charges. Two ends of theamplification rod are respectively provided with the piezoelectric elements with same polar directions, and the piezoelectric elements can simultaneously generate differential piezoelectric signals. The piezoelectric type torsional wave transducer has the advantages that the commonly-used piezoelectric ceramic plates of a thickness oscillating mode are used as the piezoelectric elements, thus thecost is low; the transducer has simple structure and simplified process; and the piezoelectric elements can be used for directly converting mechanical signals into voltage signals, thus the advantages of fewer links and high sensitivity are achieved.

The invention relates to a transparent double-measurement-system static force level gauge and a use method thereof. The transparent double-measurement system static force level gauge is characterized in that a surface measurement ruler is arranged on the outer wall of a transparent liquid storage barrel, an air pressure balance hole is formed above the transparent liquid storage barrel and can be externally connected with an air pressure balance valve, a liquid inlet is formed below the transparent liquid storage barrel and can be externally connected with a liquid inflow valve, and a liquid communicating pipe is arranged at the bottom of the transparent liquid storage barrel; a magnetostrictive liquid level meter is arranged in the transparent liquid storage barrel and connected with a circuit module arranged on the transparent liquid storage barrel, and a vertical displacement indicator lamp is connected with the circuit module. When a measurement point is displaced vertically, a pressure difference exists between a reference point and the measurement point, the magnetostrictive liquid level meter in the static force level gauge is driven to extend and shrink, and the position of the liquid level where a floater is located can be precisely determined by measuring the time difference between pulse currents and torsional waves. In addition, double-system measurement is achieved through reading of the surface measurement ruler in the static force level gauge.

The invention aims at providing a local resonance type photonic crystal vibration damping gear. The local resonance type photonic crystal vibration damping gear comprises a gear ring and a wheel hub, local resonance type photonic crystal rods are mounted on an arm of a wheel, two ends of each local resonance type photonic crystal rod are connected with the gear ring and the wheel hub in an interference manner, a welded manner or a screw fastening manner, the local resonance type photonic crystal rods comprise support rods, cladding layers and vibrators, and the cladding layers and the vibrators are mounted on the support rods from inside to outside. The local resonance type photonic crystal vibration damping gear is simple in structure and convenient to manufacture, is enabled to have good damping and noise reducing effects in a low and medium frequency area by converting torsional waves of the gear into bending waves of the support rods, is reliable to use and low in requirements on working environments, and can be used for reducing vibrating noise of a gear box under a low-and-medium-load working condition, improving working environments of workers and the like.

The invention discloses a self-calibration method and a system for a magnetostriction liquid level sensor. The method is characterized in that the method comprises the following steps of: generating a current pulse by a pulse processing module, transmitting the current pulse in a waveguide wire, contacting with a magnet in a floater, generating a torsional wave, measuring time T1 that the torsional wave is upwards transmitted to the pulse processing module and time T2 that the torsional wave is downwards transmitted to a terminal of the waveguide wire and is reflected to the pulse processing module by a singlechip; utilizing length H of a feeler lever and the time T1 and the time T2 by the singlechip, according to a formula: V=2H / (T1+T2), and obtaining a real-time velocity of propagationV; utilizing the real-time velocity of propagation V, the length H of the feeler lever and the time T1, according to a formula: h=H-V*T1, and obtaining a current liquid level height h. The invention has the advantages that: temperature influence on the waveguide wire and a crystal oscillator can be automatically removed, more accurate liquid level signals are transmitted in real time to a controlsystem of the magnetostriction liquid level sensor, and accurate measurement of a liquid level can be achieved.

The invention aims to provide a vibration reduction gear with two-dimensional quasi-phonon crystals. The vibration reduction gear comprises a spoke type cylindrical gear ring. The two-dimensional Bragg type quasi-phonon crystals are mounted at a hub of the spoke type cylindrical gear ring, end covers are fixed to the upper and lower end surfaces of the two-dimensional Bragg type quasi-phonon crystals, and the two-dimensional Bragg type quasi-phonon crystals are axially constrained by the end covers and include first phonon crystal materials and second phonon crystal materials, the second phonon crystal materials are radially and circumferentially arranged on the first phonon crystal materials, the first phonon crystal materials are radially and circumferentially arranged on the second phonon crystal materials, the two-dimensional Bragg type quasi-phonon crystals are integrally circular, and axes holes and key slots are formed in the centers of the two-dimensional Bragg type quasi-phonon crystals. The vibration reduction gear has the advantages that vibration transmission at meshed positions of the transmission axial gear ring can be greatly reduced, and an excellent suppressing effect can be realized for vibration due to torsional waves and radial waves on the gear.

A method and apparatus for generating and measuring a torsional wave in a rod, shaft or pipe using magnetostriction are provided. The magnetostrictive transducer includes at least one strip attached to a predetermined position of a rod member, an insulator disposed around the strip, a coil wound around the insulator, and magnets providing a bias magnetic field to the strip, wherein a plurality of strips are attached to the rod member at predetermined intervals in a circumferential direction, and one pole of the magnet is close to an end of a first strip among the plurality of strips, and another pole of the magnet is close to an end of a second strip among the plurality of strips.

The invention relates to a ferrite magnetostrictive displacement sensor device comprising a sensor head, a measuring rod and a moving magnetic ring assembly. The sensor head is provided with a microprocessor, a circuit processing module and a coil. The microprocessor and the circuit processing module are mounted in a closed shielding box. The circuit processing module is used for generating an excitation pulse and conditioning an echo signal. The coil is placed at one end of a waveguide wire for receiving the echo signal. The other end of the waveguide wire is provided with a damper for absorbing a torsional wave. The measuring rod includes the waveguide wire, an aluminum sleeve and a casing. The aluminum sleeve tightly wraps the waveguide wire and is disposed inside the casing. The casingis sleeved with a magnetic ring movable left and right on the casing and used for interacting with the waveguide wire. The waveguide wire uses ferrite as a magnetostrictive material. The ferrite magnetostrictive displacement sensor is greatly improved in operation stability, reduced in external interference, improved in the measurement accuracy, and reduced in cost.

A torsional sensor for sensing at least one parameter of a fluid is disclosed. The torsional sensor includes a torsional portion coupled to a reference portion and including a plurality of projections extending outward and spaced apart from each other. At least a portion of the torsional sensor is mountable for immersion in the fluid and operable to propagate a torsional wave that interacts with the fluid along the at least portion of the torsional sensor so as to affect propagation of the torsional wave in a manner dependent on the at least one parameter of the fluid.

A method for measuring an ultrasonic viscosity includes applying a driving voltage to a plurality of first piezoelectric transducers provided along an outer wall circumference of a pipe at constant intervals to generate a torsional wave on a surface of the pipe, receiving the torsional wave propagated along the surface of the pipe through a plurality of second piezoelectric transducers provided along the outer wall circumference of the pipe at constant intervals while being spaced from the first piezoelectric transducers at a certain distance in a longitudinal direction of the pipe to convert the torsional wave into a voltage signal, calculating an attenuation and a propagation velocity of the torsional wave based on the time for the propagation of the torsional wave and the converted voltage signal, and measuring viscosity of the fluid in the pipe based on the calculated attenuation and propagation velocity of the torsional wave.

An acoustic wave sensor / resonator utilizes a torsional wave trapped in an acoustic wave cavity that is formed in a noncylindrical substrate. An acoustic wave transducer is positioned adjacent the acoustic wave cavity off of the centerline of the cavity and in a plane parallel to a planar surface of the acoustic wave cavity to generate the torsional wave. The acoustic wave transducer can be a piezoelectric transducer or an electromagnetic transducer. Further, the torsional wave can be generated by a single transducer or multiple transducers.

The invention discloses a method for measuring separation of a bending wave and a torsional wave in structural bending combined vibration. The structure tends to bend and twist combined vibration whensubjected to steady state, transient or random offset-launched. It is very difficult to measure the frequency response of bending or torsional vibration alone when testing the vibration of the structure. According to the method for measuring the separation of the bending wave and the torsional wave in the structural bending combined vibration, two measuring points whose connecting line passes thegeometric center of normal section and which are symmetrical about the geometric center are selected on the normal section of the measurement position of the tested structure, bending vibration response signals and torsional vibration response signals can be obtained respectively by simply adding and subtracting the displacement response signals detected at the two points, separation of bending waves and torsional waves is achieved, and therefore structural bending combined vibration mode is better analyzed.

The present invention relates to audio signal processing, and more particularly to methods and apparatuses for emulating and controlling various features of mechanical spring reverberation in a digital audio processing system. According to certain aspects of the invention, such an emulation is performed so as to enhance or alter the characteristics of a digitally stored or processed audio signal in substantially the same manner as a mechanical spring reverberation system. In one example embodiment, the propagation of energy through a mechanical spring is simulated using dispersive waveguides, wherein left-going and right-going waves are separately processed, and the effects of dispersion and attenuation commuted to the waveguide ends. According to additional aspects, many spring reverberators contain spring elements arranged in parallel, with no coupling between springs. Accordingly, in another embodiment of the present invention, such reverberators are modeled using a set of waveguide structures, arranged in parallel, and tuned to simulate the dispersion and attenuation of the torsional propagation modes of each of the individual spring elements. According to further aspects, reverberators occasionally have spring elements comprised of spring segments connected in series. Accordingly, in yet another embodiment of the invention, such arrangements are emulated using dispersive waveguide structures with scattering junctions between modeled spring segments. According to still other embodiments of the invention, both longitudinal and torsional waves are simulated so as to produce a widening over time of successive arrivals at the simulated pick-up, to thereby account for the difference in propagation speed between the torsional and longitudinal modes.

A magnetostrictive position measuring system is provided with a waveguide and which is allocated with a magnet movable along the waveguide. An impulse generator for generating an excitation pulse and a conductive wire for guiding the excitation pulse through the waveguide to the magnet are provided, whereby a torsion wave arises in the waveguide when the excitation pulse reaches the magnet. A reel for generating a reply pulse as a function of the torsion wave and a position calculation unit for ascertaining the position of the magnet as a function of the excitation pulse and the reply pulse are provided. A processor is provided in which a table is present in which a large number of positions and excitation pulse correction values are allocated to one another. The duration of the next excitation pulse is altered as a function of the position of the magnet ascertained and the associated excitation pulse correction value from the table.