System for the non-destructive testing of components

Patent metadata

Field	Value
Publication number	US-11300545-B2
Application number	US-202015930536-A
Country	US
Kind code	B2
Filing date	May 13, 2020
Priority date	May 14, 2019
Publication date	Apr 12, 2022
Grant date	Apr 12, 2022

Abstract

In the system, two ultrasonic transducers, which form a pair and each have a piezoelectric ceramic plate-shaped element with a rectangular geometry, can be fastened to a surface of a component. The two ultrasonic transducers are arranged at a distance from one another such that there is no direct mechanical contact and they are arranged beside one another with a parallel orientation of their central longitudinal axes. The two elements have a different polarization along their width and are connected with the same polarity to an electrical voltage source. The two plate-shaped elements can also have an identical polarization along their width and can be connected in this case with opposite polarity to an electrical voltage source. At least one ultrasonic transducer and/or at least one further ultrasonic transducer is/are designed to detect ultrasonic waves reflected by defects and/or shear waves simultaneously emitted by the two ultrasonic transducers.

First claim

The invention claimed is:

1. A system for the non-destructive testing of components, comprising two ultrasonic transducers, which form a pair and each have a piezoelectric ceramic plate-shaped element with a rectangular geometry with a width, length, and thickness, which are formed on two opposite surfaces each with an electrode, fastened to a surface of a component, wherein the two ultrasonic transducers in the pair are arranged at a distance from one another such that there is no direct mechanical contact and the two ultrasonic transducers in the pair are arranged beside one another with a parallel orientation of their central longitudinal axes, and
the two piezoelectric ceramic plate-shaped elements have a different polarization along their width, and the two ultrasonic transducers in the pair are connected in this case with the same polarity to an electrical voltage source which can be operated in a pulsed manner,
or
the two piezoelectric ceramic plate-shaped elements have an identical polarization along their width, and the two ultrasonic transducers in the pair are connected in this case with opposite polarity to an electrical voltage source which can be operated in a pulsed manner, and
the electrical voltage source is designed to apply electrical voltages in a frequency range of 10 kHz to 1 MHz to the two ultrasonic transducers, and
at least one of the two ultrasonic transducers in the pair and at least one further ultrasonic transducer arranged at a known distance from the two ultrasonic transducers in the pair are designed to detect ultrasonic waves reflected by defects on the component and/or shear waves simultaneously emitted by the two ultrasonic transducers in the pair, whereby a pulse echo measurement is carried our using the at least one pair of ultrasonic transducers or a transmission/reception measurement is carried out between the at least one pair of ultrasonic transducers and the at least one further ultrasonic transducer which is arranged at a known distance from the respective pair and the detected ultrasonic waves are transmitted to an electronic evaluation and control unit, wherein the electronic evaluation unit is designed to evaluate the detected ultrasonic waves with respect to their amplitude and/or their temporal sequence.

2. The system according to claim 1 , wherein the centre or area centroid spacing of the piezoelectric ceramic plate-shaped elements of the ultrasonic transducers in the pair is an odd integer multiple of half the wavelength of the emitted ultrasonic waves.

3. The system according to claim 1 , wherein the ratio of the width to the length of the piezoelectric ceramic plate-shaped elements at least 3 to 1.

4. The system according to claim 1 , wherein the piezoelectric ceramic plate-shaped elements have a maximum thickness of 1 mm.

5. The system according to claim 1 , wherein the ultrasonic transducers in the pair can be fastened to the respective component by means of an elastically deformable material.

6. The system according to claim 1 , wherein the at least two ultrasonic transducers in the pair are embedded or laminated in an elastically deformable material.

7. The system according to claim 1 , wherein a sleeve is formed with elastically deformable material which fastens the ultrasonic transducers in the pair to the surface of the respective component such that the ultrasonic transducers rest on the respective component surface in a flat manner.

Assignees

• Fraunhofer Ges Forschung

Inventors

• Weihnacht Bianca
• Gaul Tobias
• Lieske Uwe
• Schubert Lars
• Koehler Bernd

Classifications

• B06B2201/55

  Piezoelectric transducer · CPC title

• B06B2201/74

  Underwater · CPC title

• G01N29/28

  providing acoustic coupling {, e.g. water (impedance matching G10K11/02)} · CPC title

• G01N2291/2675

  Seam, butt welding · CPC title

• G01N29/11

  by measuring attenuation of acoustic waves · CPC title