Inspection of Structures

Patent metadata

Field	Value
Publication number	US-2017248551-A1
Application number	US-201615056684-A
Country	US
Kind code	A1
Filing date	Feb 29, 2016
Priority date	Feb 29, 2016
Publication date	Aug 31, 2017
Grant date	—

Abstract

A method of detecting inconsistencies in a structure is presented. A pulsed laser beam is directed towards the structure. A plurality of types of ultrasonic signals is formed in the structure when radiation of the pulsed laser beam is absorbed by the structure. The plurality of types of ultrasonic signals is detected to form data.

First claim

What is claimed is:

1 . A method of detecting inconsistencies in a structure, the method comprising:
directing a pulsed laser beam towards the structure, wherein a plurality of types of ultrasonic signals is formed in the structure when radiation of the pulsed laser beam is absorbed by the structure; and detecting the plurality of types of ultrasonic signals to form data.

2 . The method of claim 1 , wherein the plurality of types of ultrasonic signals includes at least one of surface waves, shear waves, or longitudinal waves.

3 . The method of claim 2 further comprising:
identifying a crack in the structure using the data representing the surface waves.

4 . The method of claim 2 , wherein the surface waves are transmitted through a joint in the structure.

5 . The method of claim 2 further comprising:
identifying corrosion in the structure using data representing the shear waves.

6 . The method of claim 2 further comprising:
identifying inconsistencies on a far side of the structure using the data representing the shear waves.

7 . The method of claim 1 , wherein the pulsed laser beam is a line on a surface of the structure.

8 . The method of claim 1 , wherein the plurality of types of ultrasonic signals is detected by a point detector.

9 . The method of claim 8 , wherein the pulsed laser beam and the point detector are spaced apart such that the plurality of types of ultrasonic signals is detected.

10 . The method of claim 1 , wherein the structure is a homogenous material.

11 . The method of claim 1 , wherein the structure is formed of at least one of a composite, a metal, a ceramic, a polymeric material, a semi-conductor material, or a glass material.

12 . The method of claim 1 , wherein the structure is a single layer.

13 . A method comprising:
directing a pulsed laser beam towards a structure, wherein the pulsed laser beam is a line on a surface of the structure, wherein a plurality of types of ultrasonic signals is formed in the structure when radiation of the pulsed laser beam is absorbed by the structure, and wherein the plurality of types of ultrasonic signals includes at least one of surface waves, shear waves, or longitudinal waves; detecting the plurality of types of ultrasonic signals to form data; and determining an inconsistency is present in the structure using the data.

14 . The method of claim 13 , wherein the pulsed laser beam and a single point detector are spaced apart such that the plurality of types of ultrasonic signals is detected by the single point detector.

15 . The method of claim 13 , wherein the structure is formed of a single layer.

16 . The method of claim 13 , wherein the inconsistency includes at least one of a joint inconsistency, corrosion, an inconsistency on a far side of the structure, or a crack.

17 . An apparatus comprising:
a pulsed laser beam forming a line pump on a first surface of a structure; and a pulsed laser beam forming a point detector on the first surface of the structure.

18 . The apparatus of claim 17 , wherein the line pump and the point detector are spaced a distance apart, wherein the distance is selected such that the point detector detects a plurality of types of ultrasonic signals from the structure.

19 . The apparatus of claim 18 , wherein the plurality of types of ultrasonic signals includes at least one of surface waves, shear waves, or longitudinal waves.

20 . The apparatus of claim 17 , wherein the pulsed laser beam forming the line pump is provided by laser ultrasonic equipment.

Assignees

• Boeing Co
• Univ Washington

Inventors

• Pelivanov Ivan
• Motzer William P
• O'Donnell Matthew
• Brady Steven Kenneth
• Georgeson Gary Ernest
• Kollgaard Jeffrey Reyner
• Gordon Iii Clarence Lavere
• Bingham Jill Paisley
• Stewart Alan F
• Kennedy James C

Classifications

• G01N2291/011

  Velocity or travel time · CPC title

• G01N29/041

  on the surface of the material, e.g. using Lamb, Rayleigh or shear waves · CPC title

• G01N2291/0423

  Surface waves, e.g. Rayleigh waves, Love waves · CPC title

• G01N29/2418 Primary

  using optoacoustic interaction with the material, e.g. laser radiation, photoacoustics (photoacoustic cells G01N21/1702; measuring characteristics of vibrations by using radiation-sensitive means G01H9/00; acousto-optical conversion techniques for short-range imaging G01S15/8965; sound-producing devices using laser bundle G10K15/046) · CPC title

• G01N2291/2694

  Wings or other aircraft parts · CPC title