Ultrasonic test system, ultrasonic test method and aircraft structural object

Patent metadata

Field	Value
Publication number	US-10180410-B2
Application number	US-201615175412-A
Country	US
Kind code	B2
Filing date	Jun 7, 2016
Priority date	Jun 12, 2015
Publication date	Jan 15, 2019
Grant date	Jan 15, 2019

Abstract

According to one implementation, an ultrasonic test system includes at least one ultrasonic transducer, at least one ultrasonic sensor and a damage detection part composed of at least circuitry. The at least one ultrasonic transducer transmits an ultrasonic wave toward at least one test region. The at least one ultrasonic sensor detects the ultrasonic wave which has passed through the at least one test region. The damage detection part is configured to detect whether there is a damage in the at least one test region, based on a difference between a waveform corresponding to the ultrasonic wave detected by the at least one ultrasonic sensor and a reference waveform. The at least one ultrasonic transducer and the at least one ultrasonic sensor are disposed at positions which apart from each other with an interval longer than 300 mm.

First claim

What is claimed is:

1. An ultrasonic test system comprising:
ultrasonic transducers configured to transmit Lamb waves toward at least one test region of an object to be tested, the object comprising a material that is at least one of a metal or a composite, the object having a plate part and an elongated structural object disposed on the plate part, the ultrasonic transducers being disposed at a first side and a second side of the elongated structural object, the Lamb waves each having a frequency not less than 50 kHz and not more than 150 kHz;
optical fiber sensors configured to detect Lamb waves that have passed through the at least one test region and output detection signals in the form of oscillations in light wavelengths, the optical fiber sensors being disposed at the first side and the second side of the elongated structural object;
an optical filter configured to amplify the detection signals output from the optical fiber sensors to have larger amplitudes by oscillation of light intensities; and
a damage detection circuit configured to obtain waveforms of the Lamb waves, with each obtained waveform of a Lamb wave corresponding to at least one frequency band, the waveforms of the Lamb waves being obtained by signal processing of the detection signals amplified by the optical filter, the signal processing comprising addition averaging processing, noise reduction processing, calculating moving averages, and waveform analysis by one of a Fourier transform or a wavelet transform,
wherein the damage detection circuit is further configured to determine whether there is damage in the at least one test region based on respective differences between waveforms of the Lamb waves and reference waveforms,
wherein at least one of the ultrasonic transducers and at least one of the optical fiber sensors are disposed at respective positions spaced apart from one another by an interval of not less than 1000 mm.

2. The ultrasonic test system according to claim 1 , wherein
the ultrasonic transducers are configured to transmit Lamb waves from different positions toward the at least one test region,
at least one optical fiber sensor is configured to detect each of the Lamb waves that are transmitted from the ultrasonic transducers and passed through the at least one test region; and
the damage detection circuit is configured to determine a scope of the damage in the at least one test region based on respective differences between waveforms of the Lamb waves detected by the at least one optical fiber sensor and reference waveforms.

3. The ultrasonic test system according to claim 1 ,
wherein the ultrasonic transducers are configured to transmit each of the Lamb waves with directivity and to propagate in a sector form.

4. An aircraft structural object comprising the ultrasonic test system according to claim 1 .

5. The aircraft structural object according to claim 4 , wherein
a first oft of an ultrasonic transducer and an optical fiber sensor is disposed opposite a second pair of an ultrasonic transducer and an optical fiber sensor, the opposing pairs of ultrasonic transducers and optical fiber sensors being positioned between at least two adjacent elongated structural objects disposed on the plate part.

6. An ultrasonic test system comprising
ultrasonic transducers configured to transmit Lamb, toward at least one test region of an object to be tested, the object having a plate part and an elongated structural object disposed on the plate part, the ultrasonic transducers being disposed at a first side and a second side of the elongated structural object, the Lamb waves each having a frequency of not less than 50 kHz and not more than 150 kHz;
optical fiber sensors configured to detect Lamb waves that have passed through the at least one test region and output detection signals in the form of oscillations in light wavelengths, the optical fiber sensor being disposed at the first side and the second side of the elongated structural object;
an optical filter configured to amplify the detection signals output from the optical fiber sensors to have larger amplitudes by oscillation of light intensities; and
a damage detection circuit configured to obtain waveforms of the Lamb waves, with each obtained waveform of a Lamb wave corresponding to at least one frequency band, the waveforms of the Lamb waves being obtained by signal processing of the detection signals amplified by the optical filter, the signal processing comprising addition average processing, noise reduction processing, calculating moving averages, and waveform analysis by one of a Fourier transform or a wavelet transform,
wherein the damage detection circuit is further configured to determine whether there is damage in the at least one test region based on respective differences between waveforms of the Lamb waves and reference waveforms, and
wherein a first pair of an ultrasonic transducer and an optical fiber sensor is disposed opposite a second pair of an ultrasonic transducer and an optical fiber sensor on both the first side and the second side of the elongated structural object, the opposing pairs of ultrasonic transducers and optical fiber sensors being configured to transmit Lamb waves bidirectionally in at least the respective sides of the elongated structural object.

7. An aircraft structural object comprising the ultrasonic test system according to claim 6 .

8. The ultrasonic test system according to claim 6 , wherein
the ultrasonic transducers are configured to transmit Lamb waves from different positions toward the at least one test region,
at least one optical fiber sensor is configured to detect each of the Lamb waves that are transmitted from the ultrasonic transducers and passed through the at least one test region; and
the damage detection circuit is configured to further detect a scope of a detected damage in the at least one test region based on respective differences between waveforms of the Lamb waves detected by the at least one optical fiber sensor and reference waveforms.

9. An ultrasonic test method comprising:
transmitting Lamb waves toward a test region of an object to be tested, the object comprising a material that is at least one of a metal or a composite, the object having a plate pan and an elongated structural object disposed on the plate part, the Lamb waves being transmitted by ultrasonic transducers disposed at a first side and a second side of the elongated structural object, a frequency of each Lamb wave being not less than 50 kHz and not more than 150 kHz;
detecting the Lamb waves, having passed through the test region, by optical fiber sensors disposed at the first side and the second side of the elongated structural object;
outputting detection signals based on the detected Lamb waves, the detection signals being output from the optical fiber sensors in the form of oscillations in light wavelengths;
amplifying the detection signals by an optical filter to have larger amplitudes by oscillations of light intensities;
signal processing amplified detection signals to obtain waveforms the Lamb waves, with each obtained waveform of a Lamb wave corresponding to at least one frequency band, the signal processing comprising addition averaging processing, noise reduction processing, calculating moving averages, and waveform analysis by one of a Fourier transform or a wavelet transform; and
determining whether there is damage in the test region based on respective differences between waveforms of the Lamb waves and reference waveforms,
wherein the Lamb waves are transmitted from ultrasonic transducers and detected by optical fiber sensors, with at least one Lamb wave being transmitted by an ultrasonic transducer and detected by an optical fibe

Assignees

• Fuji Heavy Ind Ltd
• Subaru Corp

Inventors

• Takahashi Kohei
• Soejima Hideki

Classifications

• G01N29/043 Primary

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

• G01N29/041

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

• G01N29/4436

  with a reference signal (amplitude comparison G01N29/48) · 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

• G01N29/46

  by spectral analysis, e.g. Fourier analysis {or wavelet analysis (spectral signal processing per se G06F17/14)} · CPC title