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

Patent metadata

Field	Value
Publication number	US-9523661-B2
Application number	US-201113817153-A
Country	US
Kind code	B2
Filing date	Aug 17, 2011
Priority date	Aug 17, 2010
Publication date	Dec 20, 2016
Grant date	Dec 20, 2016

Abstract

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.

First claim

The invention claimed is:

1. A method of building a contour map for a damage source location in a nondestructive way using acoustic emission, comprising:
a first step of attaching at least two acoustic emission (AE) sensors within a portion to be located;
a second step of generating test locations in a structure to be located;
a third step of applying elastic waves to each of the test locations;
a fourth step of measuring acoustic emission (AE) signals by each of the AE sensors;
a fifth step of transforming the measured AE signals into times or frequencies and then into energy values; and
a sixth step of databasing the transformed energy values as parameters of information on the each of the test locations,
wherein the second step comprises: a step of partitioning the structure into lattices using the AE sensors and a step of selecting cross points of the lattices as the test locations,
the third step comprises: a step of applying the elastic waves to each of the test locations two or more times by changing a size of each of the elastic waves, and
the sixth step comprises: a step of databasing the transformed energy values as the parameters according to the size of each of the elastic waves.

2. The method of claim 1 , wherein in the sixth step, the transformed energy values based on coordinates of the cross points are databased.

3. The method of claim 1 , further comprising:
a seventh step of extending the number of energy value data databased in the sixth step,
wherein in the seventh step, data extension is made by dividing the test locations at a plurality of intervals and interpolation is performed based on an energy value at the test locations.

4. A method of locating a damage source in a nondestructive way using acoustic emission, comprising:
a first step of applying elastic waves to test locations of a structure to be located two or more times by changing sizes of the elastic waves to database measured energy values as the test locations for each acoustic emission (AE) sensor according to each size of the elastic waves;
a second step of attaching the plurality of AE sensors to a structure applied to an actual environment to monitor acoustic emission;
a third step of transforming a signal into an energy value when the AE signal is input;
a fourth step of calling the data base of the first step to extract damage location prediction regions for each AE sensor corresponding to the energy values;
a fifth step of overlaying damage source prediction regions for each AE sensor to obtain cross points and determining the cross points as damage occurrence locations, and
a sixth step of extending the damage prediction regions returning to the fourth step again after an error range is given to the elastic energy values of the third step to transform the given elastic energy values into new elastic energy values when the cross points are not obtained in the fifth step.

5. The method of claim 4 , wherein the elastic waves of the first step are applied in different sizes so as to be databased and the damage prediction region extension of the sixth step is formed for each database for the size of the elastic waves, such that the final damage occurrence locations are determined from the database having a minimum error range.

6. A method of locating a damage source in a nondestructive way using acoustic emission, comprising:
a first step of attaching at least two acoustic emission (AE) sensors within a portion to be located;
a second step of generating test locations in a structure to be located;
a third step of applying elastic waves to each test location;
a fourth step of measuring acoustic emission (AE) signals with each AE sensor;
a fifth step of transforming the measured AE signals into time or frequency and then transforming the transformed AE signals into energy values;
a sixth step of databasing the transformed energy values as parameters of information on each test locations;
a seventh step of attaching the plurality of AE sensors to a structure applied to the actual environment to monitor acoustic emission;
when the AE signals are input, an eighth step of transforming the signals into the energy values;
a ninth step of calling a database of the sixth step to extract the called database as damage source prediction regions for each AE sensor corresponding to the elastic energy of the eighth step; and
a tenth step of overlaying the damage source prediction region to obtain cross points and determine the cross points as the damage source occurrence locations,
wherein the second step comprises: a step of partitioning each test location into lattices using the AE sensor and a step of selecting cross points of each lattice as the test locations,
in the third step, the elastic waves are applied to each test location two or more times by changing each size of the elastic waves, and in the sixth step, the energy values for each test location are databased as the parameters according to each size of the elastic waves, and
when the cross points are not obtained in the tenth step, an error range is given to the energy values of the eight step to transform the given energy values into new elastic energy values, and then the step returns to the ninth step again.

Assignees

• Yoon Dong Jin
• Han Byeong Hee
• Kim Young Joo
• Korea Res Inst Standards & Sci

Inventors

• Yoon Dong Jin
• Han Byeong Hee
• Kim Young Joo

Classifications

• G01N29/069 Primary

  Defect imaging, localisation and sizing using, e.g. time of flight diffraction [TOFD], synthetic aperture focusing technique [SAFT], Amplituden-Laufzeit-Ortskurven [ALOK] technique · CPC title

• G01N29/44 Primary

  Processing the detected response signal {, e.g. electronic circuits specially adapted therefor (digital signal processing per se G06F17/00)} · CPC title

• G01N29/14

  using acoustic emission techniques {(echo of particles G01N29/046; measuring mechanical vibrations or acoustic waves in solids in general G01H1/00)} · CPC title

• G01N29/42

  by frequency filtering {or by tuning to resonant frequency} · CPC title

• G01N2291/2693

  Rotor or turbine parts · CPC title