Automated ultrasonic inspection of adhesively-bonded joints and inspection method therefor

Patent metadata

Field	Value
Publication number	US-10782268-B2
Application number	US-201815893977-A
Country	US
Kind code	B2
Filing date	Feb 12, 2018
Priority date	Feb 13, 2017
Publication date	Sep 22, 2020
Grant date	Sep 22, 2020

Abstract

An inspection system for determining the efficacy and veracity of a bond-line, comprising: a robotic arm assembly providing a gimbal mount for enabling linear and rotary translation about multiple axes; an ultrasonic transducer affixed to the gimbal mount of the robotic arm assembly and comprising a planar array of transducer elements, each transducer element capable of transmitting and receiving reflected ultrasonic energy indicative of changes in acoustic impedance within the bond-line. The reflected energy of each transducer element provides acquired bond-line data indicative of the efficacy of the bond-line while select transducer elements produce orientation data indicative of the orientation of the planar array relative to the contour of the bonded joint. The bond-line and orientation data are combined to determine whether the direction of the transmitted pulse should be altered to validate the bond-line data.

First claim

What is claimed is:

1. An inspection system for determining the efficacy of a bond-line of a bonded part, comprising:
a robotic arm assembly having a plurality of linear and rotary actuators configured to effect linear translation and rotational displacement of the robotic arm assembly about multiple axes, the robotic arm assembly including position encoders issuing position signals indicative of the instantaneous or almost instantaneous position of the robotic arm assembly;
a flexible ultrasonic transducer mounted to a housing of the robotic arm assembly, the ultrasonic transducer having an array of inspection elements, each element configured to transmit and receive ultrasonic energy indicative of the efficacy of the bond-line and issuing an ultrasonic impedance signal indicative thereof; and
a signal processor, responsive to the position signals of the robotic arm assembly and the ultrasonic impedance signals of the flexible ultrasonic transducer, to determine whether the efficacy of the bond-line is within a predetermined acceptance threshold;
wherein the ultrasonic transducer includes a plurality of transducer elements, and wherein the flexible ultrasonic transducer is mounted within a housing of the robotic arm assembly and includes at least one bore hole laterally offset from the flexible ultrasonic transducer and having an axis transverse to the direction of translational motion of the housing, the bore hole holding a coil spring for biasing a spherical ball against a surface of the bonded part.

2. The inspection system of claim 1 wherein the signal processor is configured to: (i) calculate a maximum amplitude value associated with each impedance signal, (ii) scale the maximum amplitude values associated with the impedance signal, (iii) determine whether the ratio of the amplitude values is greater than a defect threshold.

3. The inspection system of claim 1 further comprising a fluid dispenser configured to dispense a conductive fluid medium having a known acoustic impedance value between a surface of the bonded part and each of the transducer elements of the flexible ultrasonic transducer.

4. The inspection system of claim 1 wherein the signal processor calculates contour changes associated with the bonded part using select transducer elements of the flexible ultrasonic transducer to view the bond-line from a different vantage point.

5. The inspection system of claim 4 wherein the select transducer elements are disposed along a periphery of the flexible ultrasonic transducer.

6. The inspection system of claim 5 wherein the select transducer elements include one transducer element at the center of the transducer array and other transducer elements disposed along the periphery of the flexible ultrasonic transducer.

7. The inspection system of claim 2 wherein the signal processor compares the maximum amplitude value of each transducer element to a bond-line threshold, and determines whether the ratio of the amplitude values is greater than a defect threshold.

8. An inspection system for determining the efficacy of a bond-line within a bonded part, comprising:
a robotic arm assembly having a gimbal mount for enabling linear and rotary translation about multiple axes;
an ultrasonic transducer affixed to a housing mounted to the robotic arm assembly and comprising a planar array of transducer elements, each transducer element configured to acquire acoustic impedance data indicative of the efficacy of the bond-line and issue acoustic impedance signals indicative thereof;
the planar array of transducer elements including select transducer elements for developing orientation data of the ultrasonic transducer relative a surface of the bonded part; and
a signal processor, responsive to the acoustic impedance signals, to determine whether the bond-line is within a predetermined threshold, and responsive to orientation data from the select transducer elements to calculate a contour of the surface for modifying the bond-line threshold;
wherein the housing includes bore holes laterally offset from the flexible ultrasonic transducer, each of the boreholes having an axis transverse to the direction of translational motion of the housing, and holding a coil spring for biasing a spherical ball against the bonded part to facilitate movement of the housing along a surface of the bonded part.

9. The inspection system of claim 8 further comprising a fluid dispenser configured to dispense a conductive fluid medium having a known acoustic impedance value between a surface of the bonded part and each of the transducer elements of the ultrasonic transducer.

10. The inspection system of claim 8 wherein the select transducer elements are disposed along a periphery of the ultrasonic transducer.

11. The inspection system of claim 10 wherein the select transducer elements include one transducer element at the center of the transducer array and other transducer elements disposed along a periphery of the ultrasonic transducer.

12. The inspection system of claim 8 wherein the transducer elements transmit ultrasonic energy in various directions to acquire impedance signals from a variety of angles.

13. The inspection system of claim 8 wherein the signal processor determines whether the bond-line is acceptable in real-time.

14. A method for inspecting a bond-line of a bonded part, comprising the steps of:
configuring a robotic arm assembly to gimbal mount an ultrasonic transducer to effect linear and rotary translation about multiple axes, the ultrasonic transducer comprising a planar array of multiple transducer elements, wherein the ultrasonic transducer is mounted within a housing of the robotic arm assembly and includes at least one bore hole laterally offset from the flexible ultrasonic transducer and having an axis transverse to the direction of translational motion of the housing, the bore hole holding a coil spring for biasing a spherical ball against a surface of the bonded part;
measuring changes in acoustic impedance within the bond-line by transmitting/receiving reflected ultrasonic energy through the bond-line, the ultrasonic energy indicative of the efficacy of the bond-line;
measuring changes in acoustic impedance received by select transducer elements of the ultrasonic transducer, the select transducer elements developing orientation data of the ultrasonic transducer relative to a surface of the bonded part; and
using the orientation data collected by the select transducer elements and contour data of the bond-line to determine whether additional bond-line data should be collected to validate the efficacy of the bond-line.

15. The method of claim 14 wherein the step of using the orientation data of the ultrasonic transducer includes the step of comparing the acoustic impedance with the acceptance thresholds associated with each of the select transducer elements.

16. The method of claim 14 further comprising the steps of (i) calculate a maximum amplitude value associated with each impedance signal, (ii) scale the maximum amplitude values associated with the impedance signal, (iii) determine whether the ratio of the amplitude values is greater than a defect threshold.

17. The method of claim 14 further comprising the steps of dispensing a conductive fluid medium between a surface of the bonded part and each of the transducer elements of the ultrasonic transducer.

18. The method of claim 17 wherein the conductive fluid medium has a known acoustic impedance value.

Assignees

• Gen Electric

Inventors

• Kahmann Frank
• Koers Daniel
• Steinhoff Norbert Ewald
• Zhang Weiwei

Classifications

• G01N2291/0289

  Internal structure, e.g. defects, grain size, texture · CPC title

• G01N2291/0231

  Composite or layered materials · CPC title

• G01N2291/106

  one or more transducer arrays · CPC title

• G01N29/043

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

• G01N2291/0258

  Structural degradation, e.g. fatigue of composites, ageing of oils · CPC title