Abstract: The present disclosure provides methods for preparing magnetostrictive powder and magnetostrictive coating, and relates to the field of magnetic functional materials and preparation thereof. The method for preparing magnetostrictive powder includes putting metals for preparing magnetostrictive powder into a vacuum melting furnace to be melted into a solution; and atomizing the solution into fine droplets by ultrasonic atomization, so that the fine droplets are cooled and solidified into magnetostrictive powder. In the method for preparing magnetostrictive powder according to the embodiments of the present disclosure, the sizes of the prepared powder are relatively uniform, the powder yield exceeds 90%, the ultrasonic atomization energy consumption is low, and energy is saved by about ¼ compared with conventional atomization.

Abstract: Disclosed is a method for detecting leakage of a full-capacity liquefied natural gas (LNG) storage tank by acoustic emission. The method includes: detecting an amplitude of system noise by an acoustic sensor, and determining a signal acquisition threshold; acquiring an amplitude of ambient noise; acquiring an amplitude of the acoustic signal excited by the analog sound source at the distance of 0.1 m from the acoustic sensor and an amplitude of the acoustic signal excited by the analog sound source at the distance of x m from the acoustic sensor, and calculating, an attenuation coefficient of an acoustic signal passing through the outer wall of the storage tank; determining a maximum detection range of the acoustic sensor; and continuously moving the acoustic sensor on the outer wall of the storage tank in a step smaller than the maximum detection range, to perform an LNG leakage detection.

Abstract: A device and method for leakage detecting of a crude oil tank floor are provided, the leakage detection field of oil storage tank base plates is related to. The device comprises a control system, a detection robot and a plurality of acoustic signal receivers. The acoustic signal receivers and the control system are all arranged outside a crude oil tank. The control system is arranged outside the crude oil tank. The acoustic signal receivers are all connected with the control system. When the crude oil tank is detected, the detection robot is arranged in the crude oil tank. The detection robot comprises a moving mechanism, a positioning sonar and an array leakage detection sensor. The positioning sonar and the array leakage detection sensor are both arranged on the moving mechanism. The acoustic signal receivers are used for receiving sonar signals sent by the positioning sonar. The array leakage detection sensor is used for detecting a leakage point of the crude oil tank.

Abstract: The present disclosure provides a system and method for testing performance of a relay contact based on infrared thermal imaging, and relates to the field of performance testing of relay contacts. The system includes a collection device, a testing device, and a time relay. The testing device is separately connected to a tested relay and the time relay, and configured to control closing and release of a contact of the tested relay by using the time relay. The collection device is connected to the testing device, and configured to collect a temperature, a closing quantity, and working duration of the contact of the tested relay. The present disclosure resolves a limitation in existing performance testing methods for intermediate relays, which predominantly concentrate on individual parameters like voltage, current, and time, while overlooking the assessment of contact performance.

Abstract: An acoustic emission internal testing method and device for detecting corrosion of a large liquid-carrying storage tank bottom plate. An acoustic emission sensor is configured to collect an acoustic emission signal generated by an underwater acoustic transducer, and to calculate an attenuation coefficient of the acoustic emission signal when propagated by the underwater acoustic transducer through a medium, thereby determining a step distance of the storage tank robot. After the storage tank robot travels every step distance on a storage tank bottom plate, the acoustic emission sensor collects an acoustic emission signal generated by the storage tank bottom plate. Finally, the position where the storage tank bottom plate is corroded and the corrosion degree are determined according to intensity characteristic parameters and activity characteristic parameters of the acoustic emission signal collected after the storage tank robot travels every step distance.

Abstract: An apparatus and method for testing sensitivity consistency of an acoustic emission sensor are provided. The apparatus uses a cylindrical polymethyl methacrylate (PMMA) rod as a test bench. A clamping seat, a clamping block, and a mounting cylinder are mounted on one end of the test bench in cooperation. Under an action of a pressure spring, an end face of a tested sensor keeps pressure-stable coupling contact with an end face of the test bench. A bracket is mounted on another end face of the test bench, and keeps, together with a fixing seat and the clamping seat, the test bench horizontally placed on a desktop. By adjusting a width and an amplitude of a pulse excitation signal of a signal generator, and according to sensitivity distribution and aggregation between tested sensors, a consistency calculation method is used to screen out tested sensors with first, second, and third sensitivity consistency.

Abstract: The present disclosure provides methods for preparing magnetostrictive powder and magnetostrictive coating, and relates to the field of magnetic functional materials and preparation thereof. The method for preparing magnetostrictive powder includes putting metals for preparing magnetostrictive powder into a vacuum melting furnace to be melted into a solution; and atomizing the solution into fine droplets by ultrasonic atomization, so that the fine droplets are cooled and solidified into magnetostrictive powder. In the method for preparing magnetostrictive powder according to the embodiments of the present disclosure, the sizes of the prepared powder are relatively uniform, the powder yield exceeds 90%, the ultrasonic atomization energy consumption is low, and energy is saved by about ¼ compared with conventional atomization.

Abstract: The present disclosure provides a magnetostrictive guided wave sensor and a method for preparing magnetostrictive coating, relating to the field of magnetic functional materials and preparations thereof. The method includes: pretreating a surface of a test piece; and spraying magnetostrictive alloy powder on the pretreated surface of the test piece to form a magnetostrictive coating attached to the pretreated surface. In the magnetostrictive guided wave sensor and the method for preparing magnetostrictive coating according to the embodiments of the present disclosure, by spraying the magnetostrictive coating on the test piece, no coupling agent is required between the probe of the magnetostrictive coating sensor and the test piece, and the magnetostrictive coating can be formed on test pieces of any shape. In addition, the coating has a high bonding strength with the test piece, and has good tissue characteristics and magnetostrictive performance.

Abstract: A magneto acoustic emission detection method for fatigue damage of ferromagnetic metal components: First, generating an excitation magnetic field by using a sine wave voltage signal, gradually increasing a loading voltage until a magneto acoustic emission signal of a bimodal envelope with an obvious tail peak is acquired, and taking a corresponding voltage peak value as a reference voltage; second, generating an excitation magnetic field by using a square wave voltage signal equal to or higher than a reference voltage, and acquiring a magneto acoustic emission signal with a T-shaped envelope; and third, calculating the average value of peak-to-peak values of the magneto acoustic emission signal in multiple periods to serve as a characteristic parameter, and enabling the characteristic parameter to have inflection point change along with the development of the initiation and expansion of the fatigue crack, and giving a timely early warning for the failure of the component.

Abstract: The disclosure discloses a method, apparatus and system for detecting multi-mode electromagnetic acoustic and magnetic flux leakage and a sensor. The method comprises: S102, receiving an operation instruction for detecting an object to be detected, the operation instruction is used for controlling a detection sensor to enter into any one or more of working modes as follows: magnetic flux leakage detection, ultrasonic bulk wave detection, ultrasonic guided wave detection and surface wave detection; S104, controlling the detection sensor to output a corresponding detection signal according to the operation instruction; and S106, detecting the object to be detected on the basis of the detection signal. The technical solution achieves a purpose of using one sensor to realize various detection modes, such as magnetic flux leakage and electromagnetic acoustic modes, reduces complexity and cost of a detection system, and improves detection efficiency.

Abstract: A magneto acoustic emission detection method for fatigue damage of ferromagnetic metal components: First, generating an excitation magnetic field by using a sine wave voltage signal, gradually increasing a loading voltage until a magneto acoustic emission signal of a bimodal envelope with an obvious tail peak is acquired, and taking a corresponding voltage peak value as a reference voltage; second, generating an excitation magnetic field by using a square wave voltage signal equal to or higher than a reference voltage, and acquiring a magneto acoustic emission signal with a T-shaped envelope; and third, calculating the average value of peak-to-peak values of the magneto acoustic emission signal in multiple periods to serve as a characteristic parameter, and enabling the characteristic parameter to have inflection point change along with the development of the initiation and expansion of the fatigue crack, and giving a timely early warning for the failure of the component.

Abstract: Disclosed are a method and device for compressing and reconstructing data. The method includes: disposing a transmitting EMAT array and a receiving EMAT array; exciting a Lamb wave, receiving the Lamb wave, subjecting the Lamb wave to narrowband filtering with the narrowband frequency, to form detecting data x(n); analysing the detecting data with a DFT; reconstructing original detecting data and calculating a reconstruction error according to the measurement vector and the recovery matrix by using a TLBO algorithm; optimizing measurement vector and recovery matrix; transmitting the measurement vector to a supervisory device.

Abstract: A method for detecting a defect of a metal plate includes selecting N controllable emitting electromagnetic acoustic transducers EMATs as excitation transducers, and selecting M omnidirectionally receiving EMATs as receiving transducers, exciting an ultrasonic guided wave in a metal plate by a nth controllable emitting EMAT with a predetermined emission angle; determining whether each of M1 omnidirectionally receiving EMATs and the nth controllable emitting EMAT form a scattering group; for the scattering group, solving a position of a scattering point and a direction of a scattering side according to a distance between Tn and Rml, the emission angle and a travel time of the ultrasonic guided wave; performing a curve fitting on all the scattering points in directions of respective scattering sides to obtain a contour image of the defect.

Abstract: The disclosure discloses a method, apparatus and system for detecting multi-mode electromagnetic acoustic and magnetic flux leakage and a sensor. The method comprises: S102, receiving an operation instruction for detecting an object to be detected, the operation instruction is used for controlling a detection sensor to enter into any one or more of working modes as follows: magnetic flux leakage detection, ultrasonic bulk wave detection, ultrasonic guided wave detection and surface wave detection; S104, controlling the detection sensor to output a corresponding detection signal according to the operation instruction; and S106, detecting the object to be detected on the basis of the detection signal. The technical solution achieves a purpose of using one sensor to realize various detection modes, such as magnetic flux leakage and electromagnetic acoustic modes, reduces complexity and cost of a detection system, and improves detection efficiency.

Abstract: Provided is a test sensor using a magnetostrictively induced guided wave based on an open magnetic circuit, comprising an excitation coil, a receiving coil and a magnetic device, the magnetic device comprises multiple test modules circumferentially and uniformly disposed thereon so as to be absorbed to the outer side of a to-be-tested slender component, each test module comprises a housing, a permanent magnet and a magnetic plate, two adjacent housings are connected to each other via an adjusting device, the excitation coil and the receiving coil are disposed in the vicinity of the test module, and are coaxially fit on the outer side of the to-be-tested slender component, the excitation coil operates to generate induced voltage in the receiving coil after the sinusoidal alternating current is input, and a computer can determine whether a defect occurs in the to-be-tested slender component after receiving the induced voltage.

Abstract: A method for detecting a defect of a metal plate includes selecting N controllable emitting electromagnetic acoustic transducers EMATs as excitation transducers, and selecting M omnidirectionally receiving EMATs as receiving transducers, exciting an ultrasonic guided wave in a metal plate by a nth controllable emitting EMAT with a predetermined emission angle; determining whether each of M1 omnidirectionally receiving EMATs and the nth controllable emitting EMAT form a scattering group; for the scattering group, solving a position of a scattering point and a direction of a scattering side according to a distance between Tn and Rm1, the emission angle and a travel time of the ultrasonic guided wave; performing a curve fitting on all the scattering points in directions of respective scattering sides to obtain a contour image of the defect.

Abstract: Disclosed are a method and device for compressing and reconstructing data. The method includes: disposing a transmitting EMAT array and a receiving EMAT array; exciting a Lamb wave, receiving the Lamb wave, subjecting the Lamb wave to narrowband filtering with the narrowband frequency, to form detecting data x(n); analysing the detecting data with a DFT; reconstructing original detecting data and calculating a reconstruction error according to the measurement vector and the recovery matrix by using a TLBO algorithm; optimizing measurement vector and recovery matrix; transmitting the measurement vector to a supervisory device.

Abstract: Provided is a test sensor using a magnetostrictively induced guided wave based on an open magnetic circuit, comprising an excitation coil, a receiving coil and a magnetic device, the magnetic device comprises multiple test modules circumferentially and uniformly disposed thereon so as to be absorbed to the outer side of a to-be-tested slender component, each test module comprises a housing, a permanent magnet and a magnetic plate, two adjacent housings are connected to each other via an adjusting device, the excitation coil and the receiving coil are disposed in the vicinity of the test module, and are coaxially fit on the outer side of the to-be-tested slender component, the excitation coil operates to generate induced voltage in the receiving coil after the sinusoidal alternating current is input, and a computer can determine whether a defect occurs in the to-be-tested slender component after receiving the induced voltage.