METHOD AND APPARATUS FOR LOCATING A SOURCE OF DAMAGE IN A LARGE COMPOSITE MATERIAL STRUCTURE

• US 20130191040A1
• Filed: 08/17/2011
• Published: 07/25/2013
• Est. Priority Date: 08/17/2010
• Status: Active Grant

• Current Assignee: Korea Research Institute of Standards and Science
• Original Assignee: Korea Research Institute of Standards and Science
• Inventors: Yoon, Dong Jin, Kim, Young Joo, Han, Byeong Hee
• Granted Patent: US 9,523,661 B2
• Time in Patent Office: Days
• US Class Current: 702/36
• CPC Class Codes: G01N 2291/0231 Composite or layered materials
• CPC Class Codes: G01N 2291/2693 Rotor or turbine parts
• CPC Class Codes: G01N 29/069 Defect imaging, localisation and sizing using, e.g. time of flight diffraction [TOFD], synthetic aperture focusing technique [SAFT], Amplituden-Laufzeit-Ortskurven [ALOK] technique
• CPC Class Codes: G01N 29/14 using acoustic emission techniques echo of particles G01N29/046; measuring mechanical vibrations or acoustic waves in solids in general G01H1/00
• CPC Class Codes: G01N 29/42 by frequency filtering or by tuning to resonant frequency
• CPC Class Codes: G01N 29/44 Processing the detected response signal , e.g. electronic circuits specially adapted therefor digital signal processing per se G06F17/00

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.

Claims

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 AE sensors (200) within a portion to be located;

a second step of generating test locations (910) in a structure to be located;

a third step of applying elastic waves to each test location (910);

a fourth step of measuring AE signal by each AE sensor (200);

a fifth step of transforming the measured AE signal into time or frequency and then into a energy value; and

a sixth step of databasing the transformed energy value as a parameter of information on the test position (910).

2. The method of claim 1, wherein the second step includes a 2-1 step of partitioning the test locations into a lattice type using the AE sensor (200) and a 2-2 step of selecting cross points of each lattice as the test locations (910).

3. The method of claim 1, wherein in the second step, the test locations are partitioned into a lattice type using the AE sensor (200) and in the sixth step, the elastic energy transformed based on cross point coordinates of the lattice is databased.

4. The method of claim 1, further comprising:

a seventh step of extending data 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 (910) at a plurality of intervals and interpolation is performed based on an energy value at the test locations (910).

5. The method of claim 1, wherein in the third step, a size of elastic waves applied to the test locations (910) is changed and applied and in the sixth step, the test locations (910) are a database according to the size of the elastic wave.

13. The method of claim 2, wherein in the third step, a size of elastic waves applied to the test locations (910) is changed and applied and in the sixth step, the test locations (910) are a database according to the size of the elastic wave.

14. The method of claim 3, wherein in the third step, a size of elastic waves applied to the test locations (910) is changed and applied and in the sixth step, the test locations (910) are a database according to the size of the elastic wave.

15. The method of claim 4, wherein in the third step, a size of elastic waves applied to the test locations (910) is changed and applied and in the sixth step, the test locations (910) are a database according to the size of the elastic wave.

6. A method of locating a damage source in a nondestructive way using acoustic emission, comprising:

a first step of applying an elastic wave to test locations (910) of a structure to be located to database measured energy values as the test locations (910) for each AE sensor (200);

a second step of attaching the plurality of AE sensors (200) 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 (200) corresponding to the energy values; and

a fifth step of overlaying damage source prediction regions to obtain cross points and determining the cross points as damage occurrence locations.

7. The method of claim 6, wherein when the cross points are not obtained in the fifth step, an error range is given to the elastic energy values of the third step to transform the given elastic energy value into a new elastic energy value and include the sixth step of the damage prediction region extension returning to the fourth step again.

8. The method of claim 7, 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.

9. An apparatus of locating a damage source in a nondestructive way using acoustic emission, comprising:

an AE sensor (200) that detects an acoustic emission signal;

an amplification unit (300) that amplifies the detected AE signal to an analyzable size;

a signal processor (400) that processes the amplified AE signal;

an origination module (500) that originates the signal processed AE signal in a wired line or wireless;

a receiving module (700) that receives the AE signal from the origination module (500) and transmits the received AE signal to a signal analysis unit (800); and

a signal analysis unit (800) that receives the AE signal from the receiving module (700) to locate a damage source.

10. The apparatus of claim 9, wherein the originating module (500) includes an originating antenna (510) that originates the AE signal in wireless.

11. The apparatus of claim 9, wherein the receiving module (700) includes a receiving antenna (710) that receives the AE signal in wireless.

12. A method of locating a damage source in a nondestructive way using acoustic emission, comprising:

a first step of attaching at least two AE sensors (200) within a portion to be located;

a second step of generating test locations (910) in a structure to be located;

a third step of applying elastic waves to each test location (910);

a fourth step of measuring AE signals with each AE sensor (200);

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 the test locations (910);

a seventh step of attaching the plurality of AE sensors (200) 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 (200) 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.