Structural health monitoring system for a material and production method

Abstract

A structural health monitoring system includes a signal transmission element and a sensor unit. The sensor unit is designed to feed a first signal into the signal transmission element and to read out a second signal from the signal transmission element. The signal transmission element has carbon nanotubes.

Claims

1. A metallic material, comprising: structural health monitoring system, which comprises a signal transmission element, which includes carbon nanotubes; and a sensor unit with a signal generator and a signal receiver, wherein the signal generator is configured to feed a first signal into the signal transmission element and wherein the signal receiver is configured to read out a second signal from the signal transmission element, wherein the second signal is an output signal which is the result of a transmission function of the signal transmission element being applied to the first signal.

2. The metallic material of claim 1, wherein the first signal and the second signal each contain an electrical signal component, and a ratio of the first signal to the second signal determines an electrical transmission function of the signal transmission element.

3. The metallic material of claim 1, wherein the first signal and the second signal each contain a thermal signal component, and a ratio of the first signal to the second signal determines a thermal transmission function of the signal transmission element.

4. The metallic material of claim 1, wherein the signal transmission element has a plurality of transmission lines made of carbon nanotubes, and at least one of the plurality of transmission lines is coupled to the sensor unit.

5. The metallic material of claim 4, wherein a first of the plurality of transmission lines crosses a second of the plurality of transmission lines, so that the signal transmission element is formed in a reticular manner.

6. The metallic material of claim 1, wherein the signal transmission element is a continuous surface.

7. The metallic material of claim 1, wherein the signal transmission element is disposed on a surface of the material.

8. The metallic material of claim 1, wherein the signal transmission element is disposed in a surface layer of the material.

9. The metallic material of claim 1, wherein the signal transmission element is distributed over an entire material thickness of the material.

10. A method for producing a metallic material, the method comprising: producing the metallic material with a structural health monitoring system, which comprises a signal transmission element, which includes carbon nanotubes; and a sensor unit with a signal generator and a signal receiver, wherein the signal generator is configured to feed a first signal into the signal transmission element and wherein the signal receiver is configured to read out a second signal from the signal transmission element, wherein the second signal is an output signal which is the result of a transmission function of the signal transmission element being applied to the first signal, wherein the signal transmission element is incorporated in the material by rolling in, adhesive bonding, or spraying.

11. The method of claim 10, wherein the signal transmission element is used as a weld filler material or as a powder metallurgy preform material in the production of the material.

12. The method of claim 10, wherein the signal transmission element is sewn, woven or knitted into the material.

13. The method of claim 10, wherein the signal transmission element is applied to the material as a coating layer.

14. The method of claim 10, wherein the signal transmission element is stirred individually or as a weld filler material into a surface of a workpiece or into friction stir weld seams.

Description

BRIEF DESCRIPTION OF THE FIGURES

(1) FIG. 1 shows a schematic representation of a structural health monitoring system according to one embodiment, shown as an example.

(2) FIG. 2 shows a schematic representation of a material according to an additional embodiment, shown as an example.

(3) FIG. 3 shows a schematic representation of a material according to another embodiment, shown as an example.

(4) FIG. 4 shows a schematic representation of a material according to an additional embodiment, shown as an example.

(5) The representations in the figures are shown in schematic form and are not drawn true to scale. If identical reference numerals are used in the following figures, then the reference numerals relate to identical or similar elements.

DETAILED DESCRIPTION OF THE EMBODIMENTS

(6) FIG. 1 shows a structural health monitoring system 100 comprising a signal transmission element 110 and a sensor element 120. The sensor element 120 is coupled to the signal transmission element 110, so that at least one electrical signal and/or one thermal signal can be fed into the signal transmission element 110 and can be read out of the signal transmission element. For this purpose the signal is fed in and read out at different locations, so that the signal transmission element acts with the transmission function on the signal that is fed in.

(7) Changes in the structure of the signal transmission element 110 cause a change in the transmission function, so that these structural changes can be detected.

(8) In FIG. 1 the signal transmission element is shown as a flat element, which can be applied, for example, to a surface of a material.

(9) As an alternative, the signal transmission element can also have a plurality of lines or line sections, which are connected to each other in a reticular manner or in a honeycomb manner, in order to guide or more specifically to transmit the fed-in signal onto the specified paths. In such a scenario the structural changes, such as cracks, in the signal transmission element can also result in a complete break in the signal transmission.

(10) FIG. 2 shows a material 200 with a sensor unit 120, which is disposed on the surface 202 of the material. The signal transmission element is not shown in FIG. 2 for reasons relating to a better presentation, but can be disposed on the surface 202 or in the surface layer 204, as well as extend over the entire material thickness 201 of the material 200.

(11) The surface layer 204 can have a thickness or depth ranging from a few micrometers (m) to some millimeters (mm). The sensor unit 120 is mechanically coupled to the surface 202 of the material and/or is fastened to the surface.

(12) FIG. 3 shows a material 200 in the form of an airplane wing. In this case the signal transmission element 110 comprising a plurality of conductor tracks or more specifically conductor track section is disposed on the surface 202 of the airplane wing. A sensor unit 120 is also disposed on the surface 202 and is electrically and/or thermally coupled to a conductor track of the signal transmission element 110.

(13) It should be noted that the structural health monitoring system can have a plurality of sensor units 120, which are coupled to the signal transmission element 110. In this case the signals can be transmitted from a first sensor unit to a second sensor unit. Owing to the arrangement of several sensor units at different locations, the transmission function of the different conductor track sections can be checked or more specifically can be monitored, so that any structural defects that may occur can be localized.

(14) The conductor tracks of the signal transmission element 110 can be disposed, in particular, at locations of the material that are subject to high mechanical stress, for example, in the region with high surface tensions or high bending forces or stresses due to vibration.

(15) FIG. 4 shows a material 200 with a structural health monitoring system comprising a signal transmission element 110 that has three conductor tracks 110A, 110B, 110C that are separated from each other. In this case each conductor track has two sensor units 120.

(16) Thus, the transmission function of each of the three conductor tracks can be checked separately, because a first sensor unit feeds in a signal that is received and evaluated by the second sensor unit.

(17) The signal that was sent can be transmitted from the first sensor unit to the second sensor unit over an additional transmission path, so that the receiving sensor unit can determine the transmission function from the actually sent signal and the received signal. As an alternative, a previously specified sequence of signals can be sent; and the second sensor unit knows this signal sequence, so that the transmission function can be determined without an additional transmission of the transmission signal sequence.

(18) The foregoing disclosure has been set forth merely to illustrate the invention and is not intended to be limiting. Since modifications of the disclosed embodiments incorporating the spirit and substance of the invention may occur to persons skilled in the art, the invention should be construed to include everything within the scope of the appended claims and equivalents thereof.

LIST OF REFERENCE NUMERALS

(19) 100 structural health monitoring system 110 signal transmission element 120 sensor unit 200 material 201 material thickness 202 surface 204 surface layer