Method for ultrasonic inspection of structure having radiused surface using multi-centric radius focusing

Patent metadata

Field	Value
Publication number	US-11525810-B2
Application number	US-202016796280-A
Country	US
Kind code	B2
Filing date	Feb 20, 2020
Priority date	Feb 20, 2020
Publication date	Dec 13, 2022
Grant date	Dec 13, 2022

Abstract

Multi-centric radius focusing is used to inspect a radiused surface of a radiused part having a varying radius without mechanically adjusting the array sensor. A plurality of focal laws are designed to electronically steer and focus ultrasound at respective focal points corresponding to centers of curvature of a simulated radiused surface having a varying radius. The mechanical probe that carries the array sensor is located to two physical places that are outside of the radiused area and have a spatial relationship that varies less than the radius of the radiused surface varies. As the probe is moved along the radiused part, the probe maintains the array sensor at a constant location relative to the radiused part. As the array sensor scans the radiused part, the array sensor is electronically adjusted to focus at the respective focal points in sequence.

First claim

The invention claimed is:

1. A method for inspecting a radiused part having non-parallel first and second planar surfaces connected by a radiused surface, the method comprising:
(a) placing a probe body in a position relative to the radiused part such that a scan plane of an array sensor comprising a multiplicity of transducer elements and supported by the probe body intersects and is perpendicular to a lengthwise axis of the radiused surface;
(b) pulsing respective apertures of the transducer elements of the array sensor to transmit a first plurality of beams focused at a first focal point and steered at respective steering angles in the scan plane, which first plurality of beams impinge on respective regions of the radiused surface;
(c) after each beam of the first plurality of beams has been emitted, processing transducer output signals from the transducer elements of each aperture to derive a respective parameter value characterizing a strength of a respective echo returned from the radiused part following impingement of each beam of the first plurality of beams on the radiused surface;
(d) pulsing respective apertures of the transducer elements of the array sensor to transmit a second plurality of beams focused at a second focal point and steered at respective steering angles in the scan plane, which second plurality of beams impinge on respective regions of the radiused surface; and
(e) after each beam of the second plurality of beams has been emitted, processing transducer output signals from the transducer elements of each aperture to derive a respective parameter value characterizing a strength of a respective echo returned from the radiused part following impingement of each beam of the second plurality of beams on the radiused surface,
wherein the first focal point is collocated at a first center of curvature of a first circular arc having a first radius, the second focal point is collocated at a second center of curvature of a second circular arc having a second radius which is different than the first radius, and the first and second circular arcs are calculated in a frame of reference of the radiused part so that the first and second planar surfaces of the radiused part are tangent to each of the first and second circular arcs.

2. The method as recited in claim 1 , further comprising:
(e) pulsing respective apertures of the transducer elements of the array sensor to transmit a third plurality of beams focused at a third focal point and steered at respective steering angles in the scan plane, which third plurality of beams impinge on respective regions of the radiused surface; and
(f) after each beam of the third plurality of beams has been emitted, processing transducer output signals from the transducer elements of each aperture to derive a respective parameter value characterizing a strength of a respective echo returned from the radiused part following impingement of each beam of the third plurality of beams on the radiused surface,
wherein the third focal point is collocated at a third center of curvature of a third circular arc having a third radius different than the first and second radii, and the third circular arc is calculated in the frame of reference of the radiused part so that the first and second planar surfaces of the radiused part are tangent to the third circular arc.

3. The method as recited in claim 2 , wherein the first and second radii differ by a first delta radius, the first and third radii differ by a second delta radius, and the first delta radius is equal to the second delta radius.

4. The method as recited in claim 1 , wherein the parameter is amplitude.

5. The method as recited in claim 1 , further comprising:
determining a range of variation of a radius of the radiused surface, which range includes the first radius and the second radius which differ by a delta radius;
locating the first focal point where a center of a first circular arc representing a profile of the radiused surface would be located if the radius of the radiused surface were the first radius; and
locating the second focal point where a center of a second circular arc representing a profile of the radiused surface would be located if the radius of the radiused surface were the second radius.

6. The method as recited in claim 1 , wherein the array sensor of transducer elements is curved.

7. The method as recited in claim 1 , wherein the array sensor of transducer elements is linear.

8. The method as recited in claim 1 , wherein the radiused surface is concave.

9. The method as recited in claim 1 , wherein the radiused surface is convex.

10. An apparatus for inspecting a radiused part, the apparatus comprising:
an array sensor comprising a multiplicity of transducer elements;
a probe body that holds the array sensor; and
a pulser/receiver device programmed to perform operations comprising:
pulsing respective apertures of the transducer elements of the array sensor to transmit a first plurality of beams focused at a first focal point and steered at respective steering angles in a scan plane;
after each beam of the first plurality of beams has been emitted, processing transducer output signals from the transducer elements of each aperture to derive a respective parameter value characterizing a strength of a respective echo returned to the array sensor;
pulsing respective apertures of the transducer elements of the array sensor to transmit a second plurality of beams focused at a second focal point and steered at respective steering angles in the scan plane; and
after each beam of the second plurality of beams has been emitted, processing transducer output signals from the transducer elements of each aperture to derive a respective parameter value characterizing a strength of a respective echo returned to the array sensor,
wherein the first focal point is collocated at a first center of curvature of a first circular arc having a first radius, the second focal point is collocated at a second center of curvature of a second circular arc having a second radius which is different than the first radius.

11. The apparatus as recited in claim 10 , wherein the array sensor of transducer elements is curved.

12. The apparatus as recited in claim 10 , wherein the array sensor of transducer elements is linear.

13. The apparatus as recited in claim 10 , wherein the probe body is designed for a largest radius of the radiused surface to allow inspection of smaller radii of the radiused surface without any mechanical adjustments.

14. The apparatus as recited in claim 10 , further comprising a non-transitory tangible computer-readable storage medium storing a file containing digital data representing the first and second transmit focal laws and the first and second receive focal laws.

15. The apparatus as recited in claim 10 , wherein the first and second circular arcs are calculated in a frame of reference of a radiused part so that first and second planar surfaces of the radiused part are tangent to each of the first and second circular arcs.

16. A method for inspecting a radiused part, the method comprising:
(a) generating a cross-sectional model of a probe in contact with a radiused part comprising first and second surfaces connected by a radiused surface, the probe comprising an array sensor of transducer elements, the cross-sectional model comprising first and second lines representing respective profiles of the first and second surfaces and a plurality of circular arcs which span an expected range of variation of a radius of the radiused surface of the radiused part, each of the circular a

Assignees

• Boeing Co

Inventors

• Fetzer Barry A
• Bingham Jill P

Classifications

• G01N29/265

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

• G01N29/262

  by electronic orientation or focusing, e.g. with phased arrays (phased arrays per se G10K11/34) · CPC title

• G01N2291/262

  Linear objects · CPC title

• G01N29/225

  Supports, positioning or alignment in moving situation · CPC title

• G01N29/069

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