Non-destructive ultrasound testing of structures made of composite material

Patent metadata

Field	Value
Publication number	US-9632063-B2
Application number	US-201314407276-A
Country	US
Kind code	B2
Filing date	Jun 17, 2013
Priority date	Jun 19, 2012
Publication date	Apr 25, 2017
Grant date	Apr 25, 2017

Abstract

The invention relates to a diagnostic apparatus 1 for detecting delamination in the thickness of a panel of laminated composite. The diagnostic apparatus can be used to inspect a panel having a non-constant thickness along its length.
The diagnostic apparatus comprises an ultrasonic probe 30 intended to be brought into contact with the front face of the panel to be inspected, an electronic device 40 for controlling the emission and reception of ultrasonic pulses 51 by the ultrasonic probe 30 , and a display device 41 having, notably, indicators showing the presence or absence of delamination in the panel.

First claim

The invention claimed is:

1. A diagnostic apparatus for detecting delamination in the thickness of a laminated composite panel, which apparatus comprises:
an ultrasonic probe configured to be brought into contact with a face of said panel and moved over said face, said probe comprising a wheel housing a plurality of elementary transducers, wherein the wheel is configured to be placed into contact with the laminated composite panel, and
an electronic device connected to each of said transducers to control emission and reception of ultrasonic pulses by said probe by the activation of at least one of the elementary transducers,
a display device having at least a first indicator configured to be activated by the electronic device when the electronic device detects a presence of delamination in the panel,
said electronic device configured to calculate a value of a coupling indicator of a coupling of said ultrasonic probe with said face, and to switch, if the value of the coupling indicator is equal to a predetermined value, from a coupling mode to a scanning mode, the scanning mode being such that, during emission, the electronic device transmits a pulsed signal successively to the elementary transducers according to a predetermined activation sequence for the elementary transducers, and such that, during reception, the electronic device analyzes reflections of the pulsed signals received by the elementary transducers to detect delamination in a predetermined depth range of a thickness of said panel,
wherein the predetermined depth range is defined by a minimal depth and a maximum depth, and the minimal depth is a depth below a surface of the laminated composite panel in contact with the wheel and the maximum depth is a depth less than a thickness of the laminated composite panel.

2. The diagnostic apparatus as in claim 1 , wherein, in the coupling mode, during transmission, the electronic device transmits the same pulse signal simultaneously to each of the elementary transducers, and, during reception, the electronic device analyzes the signals received by the elementary transducers to calculate the value of the coupling indicator.

3. The diagnostic apparatus as in claim 1 , wherein the display device further comprises a second indicator configured to be activated by the electronic device when this device is switched to scanning mode.

4. A method for detecting delamination in a panel of laminated composite, said panel having a front face, said method using a diagnostic apparatus including: an ultrasonic probe comprising elementary transducers, an electronic device connected to each of the elementary transducers, and a display device having at least a first indicator,
wherein the method includes the following successive steps:
a) while the ultrasonic probe is in contact with the front face, emitting ultrasonic pulses from the elementary transducers into the panel and receiving ultrasonic pulses reflected by the panel;
b) calculating a value of a coupling indicator representing a coupling of the probe with the front face, wherein the calculation is performed using data representing the emitted ultrasonic pulses and the received ultrasonic pulses;
c) comparing a value of the coupling indicator with a predetermined value;
d) for activating sequence of the elementary transducers, and if the value of the coupling indicator is equal to said predetermined value:
1) emitting an ultrasonic pulse by each of the plurality of elementary transducers toward the panel;
2) receiving by each of the elementary transducers a pulse reflected by the panel;
3) reconstituting, by the electronic device of a scanning signal, based on the plurality of reflected pulses received;

e) activating an indicator of the means of presenting the information indicative of the presence of delamination in the thickness of said panel when the scanning signal has a peak having an amplitude above a predefined threshold, representing a time of flight of a received pulse whose duration is:
greater than that of a time of flight of a received pulse corresponding to the pulse reflected by said front face, and
less than that of a time of flight of a received pulse which would correspond to the pulse reflected by an element located at a distance emax from said front face.

5. The method as claimed in claim 4 , wherein the value of the coupling indicator is equal to the predetermined value when:
A) a result of a subtraction between a time of flight of a pulse received by one of the elementary transducers when the probe is in contact with the front face of the panel and a time of flight of a pulse received by the one of the elementary transducers when the probe is not in contact with said front face is shorter a predetermined threshold,
B) a rate of deformation of a pulse reflected by said front face and received by the one of the elementary transducers when the probe is in contact with said front face is greater than a predetermined rate of deformation; and
C) the results of steps A and B are valid for a number of the elementary transducers greater than a predetermined number.

6. The method as claimed in claim 4 , wherein the distance emax is less than half of a known thickness of the panel.

7. The method as claimed in claim 4 , wherein the steps of the calculation of the value of the coupling indicator and comparing the value to the predetermined value are performed at regular time intervals.

8. A method to detect delamination in a panel of a laminated composite layers using an ultrasonic probe, the method comprising:
while the ultrasonic probe is in contact with a surface of the panel, repeatedly emitting ultrasonic signals from the probe into the panel and receiving ultrasonic reflections of the emitted signals by the probe, wherein a time of flight is a period between emitting one of the ultrasonic signals and receiving a reflection of the one of the ultrasonic signals;
analyzing the received ultrasonic reflections to determine a minimum time of flight as corresponding to the ultrasonic signals reflected by the surface of the panel;
establishing as a minimum period greater than the minimum time of flight;
establishing a time of flight range bounded by the minimum period and a maximum period, wherein maximum period corresponds to a period for the ultrasonic signals to be reflected at a certain depth in the panel and the certain depth is shallower than a thickness of the panel;
as the ultrasonic probe moves over the surface of the panel, analyzing the received ultrasonic reflections to determine whether the received reflections received within the established time of flight range exceed a threshold level, and
issuing an indication of a delamination in the panel in response to the determination that the received reflections exceed the threshold level.

9. A diagnostic apparatus comprising:
an ultrasonic probe including a deformable wheel configured to be brought into contact with a surface of a laminated composite component, elementary transducers within a cavity of the wheel and a liquid within the cavity which is neutral to ultrasonic waves from the elementary transducers;
an electronic device controlling each of the elementary transducers and configured to control emission and reception of ultrasonic pulses by the activation of one or more of the elementary transducers,
a display device presenting at least a first indicator in response to a signal from the electronic device made in response to the electronic device detecting a delamination in the laminated composite component,
the electronic device is configured to calculate a value of a coupling indicator of a coupling of said ultrasonic probe with said face, and to switch, if the value of the coupling indicator

Assignees

• Airbus Operations Sas
• European Aeronautic Defence & Space Co Eads France

Inventors

• Metayer Patrick
• Pages Marion

Classifications

• G01N2291/011

  Velocity or travel time · CPC title

• G01N29/44

  Processing the detected response signal {, e.g. electronic circuits specially adapted therefor (digital signal processing per se G06F17/00)} · CPC title

• G01N2291/0289

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

• G01N2291/2694

  Wings or other aircraft parts · CPC title

• G01N2291/045

  External reflections, e.g. on reflectors · CPC title