Korea Research Institute of Standards and Science

Korea Advanced Institute of Science and Technology

Dong Jin Yoon

Young Joo Kim

Il Bum Kwon

Bong Young Ahn

Sang Hun Kim

Young Gil Kim

Seung Seok Lee

Jeong Joo Lee

Byeong Hee Han

Dusun Hwang

Young Sup Lee

Jae Hwa Kwon

Ii Bum Kwon

Provided is a method of locating a damage source of a wind turbine blade for tracking a damage source location of a blade used in a wind power generator, and more particularly, a method of locating a damage source of a wind turbine blade and an apparatus thereof in a large composite material structure capable of accurately locating a damage source even in a large composite material structure by detecting defects using contour maps written based on elastic wave energy value. The method of locating a damage source of the wind turbine blade according to the present invention can accurately locate the damage source even in the large composite material structure using at least two materials unlike the related art and can use a smaller number of AE sensor than the related art.

Method and apparatus for locating a source of damage in a large composite material structure

The present invention is effective in that automatically corrected temperature can be measured using one light source and one optical detector.

Optic fiber distributed temperature sensor system with self-correction function and temperature measuring method using thereof

Provided is an acoustic sensor for measuring a sound wave propagating through a gas such as air or a fluid such as water and an elastic wave propagating through a solid medium, and more particularly, an acoustic sensor with a piezo-arrangement film capable of detecting frequencies in a broad band or amplifying a signal at a specific frequency by comparting a waveguide into an upper waveguide and a lower waveguide by means of a compartment diaphragm and arranging piezoelectric sensors on the compartment diaphragm in several forms. The acoustic sensor can be utilized as a resonant acoustic sensor in which the piezoelectric sensors are arranged on the compartment diaphragm in the same form so that a signal at a specific frequency overlaps for high sensibility or a broadband acoustic sensor in which the piezoelectric sensors are arranged in a different form to detect frequencies in a broad band. The sensor for measuring an acoustic wave includes a waveguide including a vibrating membrane for receiving the acoustic wave, an emitting membrane for emitting the acoustic wave, and a propagation medium filled therein for propagating the acoustic wave received by the vibrating membrane; a compartment diaphragm for computing the waveguide into an upper waveguide and a lower waveguide; an omni-directional endpoint processing unit formed at an end of the waveguide for absorbing the acoustic wave received by the vibrating membrane; and a plurality of piezoelectric sensors formed on the compartment diaphragm for detecting the acoustic wave.

Acoustic sensor with piezo-arrangement film

A sensor for detecting surface defects of a metal tube solves a problem of a conventional eddy current probe in that it is difficult to detect a crack in the circumferential direction of a metal tube. The sensor includes a plurality of coils wound at a predetermined inclined angle. The plurality of coils is inserted into the inside of a metal tube. Alternating current is applied to the coils to measure a change in impedance of the coils due to a change in an eddy current generated in the metal tube, thus detecting a surface defect of the metal tube.

Sensor for detecting surface defects of metal tube using eddy current method

Provided is a physical quantity measuring method using a Brillouin optical fiber sensor. An optical fiber is set on a structure and a pair of pulse lights having different pulse widths is selected. The pulse lights are sequentially transmitted through the optical fiber to obtain back scattering lights and Brillouin gain spectra. The Brillouin gain spectra are compared to each other to calculate a normalized spectrum and a Brillouin frequency is acquired based on the normalized spectrum. The Brillouin frequency is multiplied by a conversion factor of a corresponding physical quantity of the structure to obtain the physical quantity. Accordingly, a portion of the optical fiber from which a sensing signal can be acquired is shortened to improve spatial resolution.

Physical quantity measuring method using Brillouin optical fiber sensor

Growing community of inventors

Daejeon, South Korea

Dong Jin Yoon