SENSOR INTEGRATION IN THE JOINING OF STRUCTURAL ELEMENTS

Abstract

A method for joining structural elements to a component made of at least one fiber-reinforced plastics material, includes providing at least two structural elements made of at least one fiber-reinforced plastics material having a particular matrix; providing at least one film element made of a thermoplastic heavy-duty material; arranging the at least one film element on a surface of one of the structural elements or between surfaces to be joined of the at least two structural elements to be joined; and producing the component to be joined in a curing process.

Claims

1. A method for joining structural elements to a component made of at least one fiber-reinforced plastics material, the method comprising: providing at least two structural elements made of at least one fiber-reinforced plastics material having a particular matrix; providing at least one sensor film element made of a thermoplastic material; arranging the at least one sensor film element on a surface of one of the structural elements or between surfaces to be joined of the at least two structural elements to be joined; and producing the component to be joined in a curing process.

2. The method of claim 1, wherein, when the component is produced, a durable intermediate phase is formed on the surfaces to be joined of the structural elements by the sensor film element having the matrix of the relevant structural element.

3. The method of claim 1, wherein the sensor film element comprises a polyimide or a polysulfone.

4. The method of claim 3, wherein the sensor film element forms a sensor holder made of polyetherimide or polyethersulfone.

5. The method of claim 1, wherein, before being provided, the at least one sensor film element is designed as a sensor holder that is provided with at least one sensor or a plurality of sensors.

6. The method of claim 5, wherein at least one of arranging the at least one sensor film element on a surface of one of the structural elements or between surfaces to be joined of the at least two structural elements to be joined is monitored by at least one sensor or a plurality of sensors of the sensor holder.

7. The method of claim 5, wherein one or more parameters relevant to the particular process are recorded by the sensors.

8. The method of claim 7, wherein one or more of temperature, pressure and degree of curing are recorded as the parameters.

9. The method of claim 8, wherein the sensor holder is provided with at least one metal conductor track in order to record the temperature as a parameter.

10. The method of claim 9, wherein the at least one metal conductor track comprises a meandering metal conductor track.

11. The method of claim 8, wherein the sensor holder is provided with metal conductor tracks made of at least two metal materials in order to record the temperature as a parameter.

12. The method of claim 5, wherein at least one of the sensors or a subgroup of the sensors is designed as a sensor/actuator combination.

13. The method of claim 5, wherein the at least one sensor is an ultrasonic transducer.

14. The method of claim 13, wherein the at least one sensor is designed as a piezoelectric element.

15. The method of claim 5, wherein producing the component to be joined in a curing process is performed in a hot isostatic or unidirectional manner.

16. The method of claim 1, wherein the arrangement of the film element on a structural element surface is monitored.

17. The method of claim 1, wherein the joining of two structural elements between which the sensor film element is arranged is monitored.

18. The method of claim 1, wherein, when the joined component is in operation, the sensor holder is used to perform one of the group of monitoring the state of the component and detecting damage.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The disclosure herein will be described in greater detail in the following with reference to embodiments in the drawings, in which the FIGURE is a partially schematic, flat cross-sectional side view of an embodiment of a sensor arrangement having a sensor holder, sensor structure and passivation for arrangement, for example, between plastics layers of a structural element.

DETAILED DESCRIPTION

[0026] The single FIGURE, FIG. 1, shows a sensor arrangement, denoted overall as 10, that is provided to record process parameters in situ on or within structural elements 1 (not shown in detail), for which conductor tracks 16 are applied to a film element 5, which is designed as a sensor holder 20, as sensor structures 15 or parts thereof. In order to take temperature measurements, i.e. in order to determine temperatures as state variables, sensor structures 15 can be used in this case as a resistance thermometer. Thermometer is laminated between the fiber-reinforced plastics layers (CFRP layers) (not shown in greater detail) of the structural element 1 and is intended, for example, to allow for local temperature analysis during the infiltration process and curing process.

[0027] By way of example, the width of the conductor track 16 that is shown, as a measurement line or power supply line, is 30 μm. In order to precisely determine the current temperature, two power supply lines and two measurement lines may be advantageous in this case. A thermoplastic film made of polyetherimide (PEI) was used as the substrate material of the sensor holder 20.

[0028] In the first manufacturing step, feed lines and contact pads (not shown) are printed using an inkjet method, for example. The sensor structure 15 is then applied using an aerosol jet method, for instance. As a final manufacturing step, an insulating layer 17 is applied over the conductor tracks 16 of the sensor structure 15, which layer shields the sensor structure 15 from the conductive surroundings. The screen printing technique, for example, is used to apply the insulating layer 17, which is substantially on the side of the sensor structure 15 that is remote from the sensor holder 20, as can be seen from FIG. 1. A passivation of this kind can, for example, be reapplied as a layer made of PEI, but also as a polyimide layer or as a solder resist. After each screen printing process, the applied passivation layer 17 can be cured.

[0029] The sensor structures 15 applied to the sensor holders 20 are inserted between the CFRP layers (not shown) of a structural element 1, which is then infiltrated and cured in an autoclave in order to establish the integral joining connection between the sensor holder 20 and the structural element 1.

[0030] The disclosure herein described above thus relates to a method for joining structural elements 1 to a component made of at least one fiber-reinforced plastics material, comprising the following method steps: providing at least two structural elements 1 made of at least one fiber-reinforced plastics material having a particular matrix; providing at least one sensor film element 5 made of a thermoplastic material; arranging the at least one sensor film element 5 on a surface of one of the structural elements 1 or between surfaces to be joined of the at least two structural elements 1 to be joined; and producing the component to be joined in a curing process. When the structural element 1 is produced, the sensor film element 5 forms an integral joining connection to the matrix of the structural element.

[0031] Although the present disclosure has been described above with reference to a preferred embodiment, the disclosure herein is not limited thereto but may rather be modified in many different ways. In particular, the disclosure herein may be altered or modified in various ways, without deviating from the basic concept of the disclosure herein.

[0032] While at least one exemplary embodiment of the present invention(s) is disclosed herein, it should be understood that modifications, substitutions and alternatives may be apparent to one of ordinary skill in the art and can be made without departing from the scope of this disclosure. This disclosure is intended to cover any adaptations or variations of the exemplary embodiment(s). In addition, in this disclosure, the terms “comprise” or “comprising” do not exclude other elements or steps, the terms “a”, “an” or “one” do not exclude a plural number, and the term “or” means either or both. Furthermore, characteristics or steps which have been described may also be used in combination with other characteristics or steps and in any order unless the disclosure or context suggests otherwise. This disclosure hereby incorporates by reference the complete disclosure of any patent or application from which it claims benefit or priority.