Apparatus and method for modulated-frequency ultrasonic inspection of structures

Patent metadata

Field	Value
Publication number	US-11280760-B2
Application number	US-201916591216-A
Country	US
Kind code	B2
Filing date	Oct 2, 2019
Priority date	Oct 2, 2019
Publication date	Mar 22, 2022
Grant date	Mar 22, 2022

Abstract

Disclosed herein is a non-destructive inspection (NDI) apparatus. The NDI comprises a main body and a modulated-frequency ultrasonic source, coupled to the main body. The modulated-frequency ultrasonic source comprises a low-frequency ultrasonic source, selectively operable to emit a low-frequency ultrasonic beam having a first frequency. The modulated-frequency ultrasonic source also comprises a high-frequency ultrasonic source, selectively operable to emit a high-frequency ultrasonic beam having a second frequency higher than the first frequency. The modulated-frequency ultrasonic source is configured to mix the low-frequency ultrasonic beam and the high-frequency ultrasonic beam at least at a surface of a structure to be inspected.

First claim

What is claimed is:

1. A non-destructive inspection (NDI) apparatus, comprising:
a main body; and
a modulated-frequency ultrasonic source, coupled to the main body and comprising:
a low-frequency ultrasonic source, selectively operable to emit a low-frequency ultrasonic beam having a first frequency; and
a high-frequency ultrasonic source, selectively operable to emit a high-frequency ultrasonic beam having a second frequency higher than the first frequency;

wherein:
the modulated-frequency ultrasonic source is configured to mix the low-frequency ultrasonic beam and the high-frequency ultrasonic beam at least at a surface of a structure to be inspected; and
the modulated-frequency ultrasonic source further comprises at least one ultrasonically reflective surface, positioned relative to one of the low-frequency ultrasonic source or the high-frequency ultrasonic source, to receive and redirect one of the low-frequency ultrasonic beam or the high-frequency ultrasonic beam to mix with the other one of the low-frequency ultrasonic beam or the high-frequency ultrasonic beam at least at the surface of the structure to be inspected.

2. The NDI apparatus according to claim 1 , wherein each one of the low-frequency ultrasonic source and the high-frequency ultrasonic source comprises a piezoelectric material.

3. The NDI apparatus according to claim 1 , wherein:
the modulated-frequency ultrasonic source further comprises a plurality of ultrasonically reflective surfaces;
a first one of the plurality of ultrasonically reflective surfaces is positioned relative to the low-frequency ultrasonic source to receive and redirect the low-frequency ultrasonic beam to mix with the high-frequency ultrasonic beam; and
a second one of the plurality of ultrasonically reflective surfaces is positioned relative to the high-frequency ultrasonic source to receive and redirect the high-frequency ultrasonic beam to mix with the low-frequency ultrasonic beam.

4. The NDI apparatus according to claim 3 , wherein the modulated-frequency ultrasonic source further comprises a vibration damper interposed between the low-frequency ultrasonic source and the high-frequency ultrasonic source, wherein the low-frequency ultrasonic source and the high-frequency ultrasonic source are arranged in a back-to-back configuration such that the low-frequency ultrasonic source emits the low-frequency ultrasonic beam in a first direction and the high-frequency ultrasonic source emits the high-frequency ultrasonic beam in a second direction opposite the first direction.

5. The NDI apparatus according to claim 4 , wherein:
the vibration damper comprises a first damping material and a second damping material;
the first damping material is interposed between the low-frequency ultrasonic source and the second damping material;
the second damping material is interposed between the first damping material and the high-frequency ultrasonic source; and
a damping coefficient of the first damping material is lower than a damping coefficient of the second damping material.

6. The NDI apparatus according to claim 1 , wherein the low-frequency ultrasonic source and the high-frequency ultrasonic source are arranged in a side-by-side configuration such that the low-frequency ultrasonic source emits the low-frequency ultrasonic beam at a first distance away from the surface of the structure and the high-frequency ultrasonic source emits the high-frequency ultrasonic beam at the first distance away from the surface of the structure.

7. The NDI apparatus according to claim 6 , wherein:
the at least one ultrasonically reflective surface receives and redirects both the low-frequency ultrasonic beam and the high-frequency ultrasonic beam to mix the low-frequency ultrasonic beam and the high-frequency ultrasonic beam;
the low-frequency ultrasonic source emits the low-frequency ultrasonic beam in a first direction; and
the high-frequency ultrasonic source emits the high-frequency ultrasonic beam in a second direction different than the first direction.

8. The NDI apparatus according to claim 6 , wherein:
the modulated-frequency ultrasonic source further comprises a plurality of ultrasonically reflective surfaces;
a first one of the plurality of ultrasonically reflective surfaces receives and redirects the low-frequency ultrasonic beam to mix with the high-frequency ultrasonic beam;
a second one of the plurality of ultrasonically reflective surfaces receives and redirects the high-frequency ultrasonic beam to mix with the low-frequency ultrasonic beam;
the low-frequency ultrasonic source emits the low-frequency ultrasonic beam in a first direction;
the high-frequency ultrasonic source emits the high-frequency ultrasonic beam in the first direction; and
the first one of the plurality of ultrasonically reflective surfaces is angled relative to the second one of the plurality of ultrasonically reflective surfaces.

9. The NDI apparatus according to claim 6 , wherein:
the modulated-frequency ultrasonic source further comprises a plurality of ultrasonically reflective surfaces;
the low-frequency ultrasonic source emits the low-frequency ultrasonic beam in a first direction and emits a second low-frequency ultrasonic beam in a second direction opposite the first direction;
the high-frequency ultrasonic source emits the high-frequency ultrasonic beam in the first direction and emits a second high-frequency ultrasonic beam in the second direction;
a first one of the plurality of ultrasonically reflective surfaces receives and redirects both the low-frequency ultrasonic beam and the high-frequency ultrasonic beam to mix the low-frequency ultrasonic beam, the high-frequency ultrasonic beam, the second low-frequency ultrasonic beam, and the second high-frequency ultrasonic beam at least at the surface of the structure to be inspected; and
a second one of the plurality of ultrasonically reflective surfaces receives and redirects both the second low-frequency ultrasonic beam and the second high-frequency ultrasonic beam to mix the second low-frequency ultrasonic beam, the second high-frequency ultrasonic beam, the low-frequency ultrasonic beam, and the high-frequency ultrasonic beam at least at the surface of the structure to be inspected.

10. The NDI apparatus according to claim 1 , wherein:
the low-frequency ultrasonic source and the high-frequency ultrasonic source are arranged in a front-to-back configuration such that the low-frequency ultrasonic source emits the low-frequency ultrasonic beam at a first distance away from the surface of the structure and the high-frequency ultrasonic source emits the high-frequency ultrasonic beam at a second distance away from the surface of the structure; and
the first distance is greater than the second distance.

11. The NDI apparatus according to claim 10 , wherein:
the modulated-frequency ultrasonic source further comprises a plurality of ultrasonically reflective surfaces;
a first one of the plurality of ultrasonically reflective surfaces receives and redirects the low-frequency ultrasonic beam to mix the low-frequency ultrasonic beam and the high-frequency ultrasonic beam;
a second one of the plurality of ultrasonically reflective surfaces receives and redirects the high-frequency ultrasonic beam to mix the high-frequency ultrasonic beam and the low-frequency ultrasonic beam;
the low-frequency ultrasonic source emits the low-frequency ultrasonic beam in a first direction; and
the high-frequency ultrasonic source emits the high-frequency ultrasonic beam in a second direction opposite the first direction.

12. The NDI apparatus according to claim 10 , wherein:
the modulated-frequen

Assignees

• Boeing Co

Inventors

• Fetzer Barry A
• Georgeson Gary E

Classifications

• G01N2291/263

  Surfaces · CPC title

• G01N29/041 Primary

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

• G01N29/2437

  Piezoelectric probes · CPC title

• G01N29/265

  by moving the sensor relative to a stationary material · CPC title

• G01N29/043

  in the interior, e.g. by shear waves · CPC title