Abstract: An apparatus for improving transmission directivity according to an embodiment of the present invention includes a phased array probe including a channel 1 transducer and a channel 2 transducer which are arranged at intervals corresponding to a quarter wavelength at a center frequency of a guided wave pulse for long-range ultrasonic testing, and a drive unit which supplies electric pulses with opposite phases to the channel 1 transducer and the channel 2 transducer of the channel 1 transducer and the channel 2 transducer, which is disposed on the front end on the basis of an intended transmission direction, is driven with delay by a time corresponding to a quarter frequency of the center frequency than the other transducer disposed on the rear end.

Abstract: An apparatus for improving transmission directivity according to an embodiment of the present invention includes a phased array probe including a channel 1 transducer and a channel 2 transducer which are arranged at intervals corresponding to a quarter wavelength at a center frequency of a guided wave pulse for long-range ultrasonic testing, and a drive unit which supplies electric pulses with opposite phases to the channel 1 transducer and the channel 2 transducer of the channel 1 transducer and the channel 2 transducer, which is disposed on the front end on the basis of an intended transmission direction, is driven with delay by a time corresponding to a quarter frequency of the center frequency than the other transducer disposed on the rear end

Abstract: A contact shear horizontal (SH) mode guided-wave magnetostrictive transducer including: a transduction band which is disposed on a surface of an object to be tested and in which electromagnetic acoustic transduction occurs; and radio frequency (RF) coils disposed on the transduction band, wherein the transduction band includes a plate-shaped solenoid including a magnetostrictive strip in which the electromagnetic acoustic transduction for transmitting or receiving SH mode guided waves occurs, and solenoid coil wound in a spiral form along a circumference of the magnetostrictive strip so as to form a bias magnetic field in a lengthwise direction of the magnetostrictive strip, and the RF coils are used to form a dynamic magnetic field in a widthwise direction of the magnetostrictive strip or to detect a change of magnetic flux in the magnetostrictive strip.

Abstract: A method for manufacturing a spiral coil, the method including: forming a solenoid having a diameter larger than a length by spirally winding an insulated electric wire; forming a spiral coil having folded corners by folding four corners in a circumference direction with respect to the solenoid; fixing the folded corners of the spiral coil; and fixing two terminal portions corresponding to start and end points of the spiral coil to a fixing module. According to the method, a thin and long spiral coil having folded corners is easily manufactured by using a general insulated electric wire. In addition, the spiral coil manufactured by using such a method is applicable to a surface radio frequency (RF) coil optimized for various applications of an electro-magnetic acoustic transducer (EMAT) and enables easy access to an optimized transducer.

Abstract: A contact shear horizontal (SH) mode guided-wave magnetostrictive transducer including: a transduction band which is disposed on a surface of an object to be tested and in which electromagnetic acoustic transduction occurs; and radio frequency (RF) coils disposed on the transduction band, wherein the transduction band includes a plate-shaped solenoid including a magnetostrictive strip in which the electromagnetic acoustic transduction for transmitting or receiving SH mode guided waves occurs, and solenoid coil wound in a spiral form along a circumference of the magnetostrictive strip so as to form a bias magnetic field in a lengthwise direction of the magnetostrictive strip, and the RF coils are used to form a dynamic magnetic field in a widthwise direction of the magnetostrictive strip or to detect a change of magnetic flux in the magnetostrictive strip.

Abstract: A method for manufacturing a spiral coil, the method including: forming a solenoid having a diameter larger than a length by spirally winding an insulated electric wire; forming a spiral coil having folded corners by folding four corners in a circumference direction with respect to the solenoid; fixing the folded corners of the spiral coil; and fixing two terminal portions corresponding to start and end points of the spiral coil to a fixing module. According to the method, a thin and long spiral coil having folded corners is easily manufactured by using a general insulated electric wire. In addition, the spiral coil manufactured by using such a method is applicable to a surface radio frequency (RF) coil optimized for various applications of an electro-magnetic acoustic transducer (EMAT) and enables easy access to an optimized transducer.

Abstract: A method and system for simulating defects in conduits, where the defects are detected using long-range guided-wave inspection techniques. The guided wave interaction with a defect is treated as a one-dimensional problem of plane wave reflection from a boundary of different acoustic impedances. The defect waveform is simulated using an electrical transmission line model and inverse fast Fourier transformation.

Abstract: A method and system for simulating defects in conduits, where the defects are detected using long-range guided-wave inspection techniques. The guided wave interaction with a defect is treated as a one-dimensional problem of plane wave reflection from a boundary of different acoustic impedances. The defect waveform is simulated using an electrical transmission line model and inverse fast Fourier transformation.

Abstract: 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.

Abstract: A method and apparatus is shown 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 said 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.