Composite repair

Abstract

The invention relates to composite repair. A method for repairing a thermoplastic composite part is presented. A heating element impregnated with a thermoplastic material is placed onto the repair area of the thermoplastic composite part. The thermoplastic material of the heating element is adhered to the repair area by generating heat in the heating element from an electrical current applied to the heating element. After the heating element is adhered to the repair area, a repair patch is placed on the heating element. A current is applied to the heating element to heat the repair patch to a patch processing temperature.

Description

Technical Field

[0001] The present disclosure relates generally to composite repair and, more particularly, to repairing thermoplastic composite parts using heating elements comprising thermoplastic materials. Background Art

[0002] Currently, repair technologies for thermoplastic composite parts are being designed and studied. Some thermosetting patches can be applied using adhesives to bond the thermosetting patches to the thermoplastic parts. A heating blanket can be used to cure the thermosetting patches. Current thermosetting adhesion methods use energy surface pretreatment methods, such as plasma treatment, on thermoplastic parts. Energy surface treatment has time limitations on availability. In addition, the energy surface pretreatment method must be able to reach the area of the thermoplastic composite part that needs to be treated. On some parts of vehicles and other platforms, it may be difficult to access. Bonding thermosetting patches to thermoplastic parts may be undesirably time-consuming and difficult to expand to large-area parts.

[0003] Therefore, it would be desirable to have methods and apparatus that take into account at least some of the above-mentioned issues, as well as other possible issues.It would be desirable to have a thermoplastic repair method that uses at least one of less time or less energy. Summary of the Invention

[0004] Embodiments of the present disclosure provide a method for repairing a thermoplastic composite component. A heating element impregnated with a thermoplastic material is placed over a repair area of the thermoplastic composite component. Heat generated in the heating element by an electric current applied to the heating element causes the thermoplastic material of the heating element to adhere to the repair area. After the heating element is adhered to the repair area, a repair patch is placed over the heating element. An electric current is applied to the heating element to heat the repair patch to a patch processing temperature.

[0005] Another embodiment of the present disclosure provides a method for repairing a thermoplastic composite component. A heating element impregnated with a thermoplastic material is placed over a repair area of a thermoplastic composite component. Current applied to the heating element generates heat within the heating element, causing the thermoplastic material of the heating element to adhere to the repair area. After the heating element has adhered to the repair area, a thermoplastic repair patch is placed over the heating element. The thermoplastic repair patch is heated to a patch processing temperature using the heating element. Pressure is applied to the thermoplastic repair patch while the thermoplastic repair patch is heated.

[0006] Yet another embodiment of the present disclosure provides a method for repairing a thermoplastic composite component. A heating element impregnated with a thermoplastic material is placed over a repair area of a thermoplastic composite component. Current applied to the heating element generates heat in the heating element, causing the thermoplastic material of the heating element to adhere to the repair area. After the heating element has adhered to the repair area, a thermosetting repair patch is placed over the heating element. The thermosetting repair patch is heated to a patch processing temperature using the heating element. Pressure is applied to the thermosetting repair patch while the patch is heated.

[0007] The features and functions may be achieved independently in various embodiments of the present disclosure or may be combined in yet other embodiments in which further details can be seen with reference to the following description and drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] The novel features which are believed to be characteristic of the illustrative embodiments are set forth in the appended claims. However, the illustrative embodiments, together with the preferred mode of use, further objects and features thereof, will be best understood by reference to the following detailed description of illustrative embodiments of the present disclosure when read in conjunction with the accompanying drawings, in which:

[0009] Figure 1 is a diagram of an aircraft according to an illustrative embodiment;

[0010] Figure 2 is an illustration of a block diagram of a manufacturing environment according to an illustrative embodiment;

[0011] Figure 3 is a cross-sectional view of a repair of a thermoplastic composite part according to an illustrative embodiment;

[0012] Figure 4 is a cross-sectional view of a repair of a thermoplastic composite part according to an illustrative embodiment;

[0013] Figure 5 is a cross-sectional view of a repair of a thermoplastic composite part according to an illustrative embodiment;

[0014] Figure 6 is a cross-sectional view of a repair of a thermoplastic composite part according to an illustrative embodiment;

[0015] Figure 7A and Figure 7B is a flow chart of a method of repairing a thermoplastic composite part according to an illustrative embodiment;

[0016] Figure 8 is a flow chart of a method of repairing a thermoplastic composite part according to an illustrative embodiment;

[0017] Figure 9 is a flow chart of a method of repairing a thermoplastic composite part according to an illustrative embodiment;

[0018] Figure 10 is a flow chart of a method of repairing a thermoplastic composite part according to an illustrative embodiment;

[0019] Figure 11 is an illustration, in block diagram form, of an aircraft manufacturing and service methodology in accordance with an illustrative embodiment; and

[0020] Figure 12 is an illustration, in block diagram form, of an aircraft in which illustrative embodiments may be implemented. DETAILED DESCRIPTION

[0021] Now turn Figure 1 , an illustration of an aircraft is depicted in accordance with an illustrative embodiment. Aircraft 100 has wings 102 and wing 104 attached to fuselage 106. Aircraft 100 includes engines 108 attached to wing 102 and engines 110 attached to wing 104.

[0022] Fuselage 106 has tail section 112 . Horizontal stabilizer 114 , horizontal stabilizer 116 , and vertical stabilizer 118 are attached to tail section 112 of fuselage 106 .

[0023] Aircraft 100 is an example of an aircraft that may have a thermoplastic composite component to be repaired. The illustrative examples may be used to repair a thermoplastic composite component in at least one of wing 102, wing 104, fuselage 106, horizontal stabilizer 114, horizontal stabilizer 116, or vertical stabilizer 118 of aircraft 100.

[0024] Now turn Figure 2 , an illustration of a block diagram of a manufacturing environment is depicted in accordance with an illustrative embodiment. Manufacturing environment 200 is an environment in which thermoplastic composite part 202 may be repaired. In this illustrative example, heating element 206 is applied to repair area 204 to adhere repair patch 208 to thermoplastic composite part 202. Repair patch 208 may include thermoplastic repair patch 210 or thermoset repair patch 212.

[0025] Thermoplastic composite part 202 includes composite material 214 having a melting temperature 216. Heating element 206 is impregnated 226 with thermoplastic material 218. Thermoplastic material 218 may be referred to as low-melting-point 220 thermoplastic material 218. Because melting temperature 222 of thermoplastic material 218 is lower than melting temperature 216 of thermoplastic composite part 202, thermoplastic material 218 may be referred to as low-melting-point 220 thermoplastic material 218. Heating element 206 may be heated from room temperature to the desired joining temperature at a very fast rate (150° C. / min).

[0026] Carbon conductive material 224 is present in heating element 206 to melt thermoplastic material 218, thereby adhering heating element 206 to thermoplastic composite part 202. When electric current 223 is applied to carbon conductive material 224, carbon conductive material 224 generates heat. In some illustrative examples, carbon conductive material 224 is one of a fiber, a mesh, a coil, or a unidirectional tape. In some illustrative examples, carbon conductive material 224 generates heat to melt thermoplastic material 218. In some illustrative examples, carbon conductive material 224 has a thickness in the range of 0.005 inches to 0.02 inches. When electric current 223 is applied to carbon conductive material 224, carbon conductive material 224 generates heat.

[0027] A control system 225 is provided to control the application of current 223. In some illustrative examples, current 223 is controlled based on a feedback control loop. A temperature sensor may be provided to monitor the temperature of heating element 206. Control system 225 is configured to control current 223 applied to carbon conductive material 224 based on the temperature of at least one of thermoplastic composite part 202, heating element 206, or repair patch 208.

[0028] Thermoplastic material 218 may take any desired form having a melting temperature 222 that is less than melting temperature 216 of thermoplastic composite part 202 .

[0029] In some illustrative examples, thermoplastic material 218 is polyaryletherketone. In some illustrative examples, polyaryletherketone has a melting temperature 222 in the range of 260 to 350 degrees Celsius. In some illustrative examples, thermoplastic material 218 is polyetherketoneketone. In some illustrative examples, thermoplastic material 218 is polyetheretherketone. In some illustrative examples, thermoplastic material 218 is a blend of two thermoplastic materials.

[0030] In some illustrative examples, the mixture of the two thermoplastic materials has a melting temperature 222 in the range of 260 to 350 degrees Celsius and a glass transition temperature in the range of 180 to 200 degrees Celsius. The glass transition temperature can be used to bond heating element 206 to a thermoset material, such as when repair patch 208 takes the form of thermoset repair patch 212. In some illustrative examples, when repair patch 208 takes the form of thermoset repair patch 212, thermoplastic material 218 is a mixture.

[0031] In some illustrative examples, thermoplastic material 218 to join thermoset repair patch 212 and thermoplastic composite part 202 is a mixture of two thermoplastic materials. In some illustrative examples, thermoplastic material 218 to join two thermoplastic composite parts, such as thermoplastic composite part 202 and thermoplastic repair patch 210, is a single thermoplastic material having a melting temperature 222.

[0032] Heating element 206 impregnated 226 with thermoplastic material 218 is applied to repair region 204 of thermoplastic composite part 202. Repair region 204 may take any desired form. In some illustrative examples, repair region 204 is surface 228 over inconsistent region 232. In these illustrative examples, inconsistent region 232 may remain in thermoplastic composite part 202.

[0033] In some illustrative examples, creation region is created by removing an inconsistent region from thermoplastic composite part 202. In some illustrative examples, repair region 204 includes surface 228 of thermoplastic composite part 202 located in cut 234 formed by removing inconsistent region 232 from thermoplastic composite part 202.

[0034] In some illustrative examples, repair region 204 includes portion 230 of thermoplastic composite component 202 after inconsistent region 232 has been removed from thermoplastic composite component 202. In some illustrative examples, a series of composite material layers have been cut away from thermoplastic composite component 202 to create repair region 204.

[0035] Repair area 204 may have any desired size or shape. In some illustrative examples, repair area 204 is scarfed 236 .

[0036] The thermoplastic material 218 of the heating element 206 adheres to the repair area 204 by generating heat in the heating element 206 from an electrical current 223 applied to the heating element 206. After the heating element 206 is adhered to the repair area 204, the repair patch 208 is placed on the heating element 206. An electrical current 223 is applied to the heating element 206 to heat the repair patch 208 to a patch processing temperature.

[0037] In some illustrative examples, thermoplastic repair patch 210 is already consolidated and is the same material as thermoplastic composite part 202. When the repair patch takes the form of thermoplastic repair patch 210, current 223 is applied to heating element 206 to heat thermoplastic repair patch 210 to a patch processing temperature 238. Patch processing temperature 238 is selected to consolidate thermoplastic repair patch 210. In some illustrative examples, patch processing temperature 238 is approximately 280° C. to 340° C. In some illustrative examples, patch processing temperature 238 is approximately 310° C.

[0038] During the heating of the thermoplastic repair patch 210, pressure 240 is applied to the thermoplastic repair patch 210 to compress the thermoplastic repair patch 210. In some illustrative examples, approximately 15 psi to 45 psi of pressure 240 is applied to the thermoplastic repair patch 210 while the thermoplastic repair patch 210 is heated to bond the thermoplastic repair patch 210 to the thermoplastic composite part 202. In some illustrative examples, approximately 30 psi of pressure 240 is applied to the thermoplastic repair patch 210 while the thermoplastic repair patch 210 is heated to bond the thermoplastic repair patch 210 to the thermoplastic composite part 202. In some illustrative examples, after the thermoplastic repair patch 210 is allowed to cool to 150° C., the pressure 240 is removed from the thermoplastic repair patch 210. When the repair patch is in the form of a thermosetting repair patch 212, an electric current 223 is applied to the heating element 206 to heat the thermosetting repair patch 212 to a patch processing temperature 242. The patch processing temperature 242 is selected to cure the thermosetting repair patch 212. In some illustrative examples, the patch processing temperature 242 is approximately 170° C. to 190° C. In some illustrative examples, the patch processing temperature 242 is approximately 180° C.

[0039] During the heating of thermoset repair patch 212, pressure 244 is applied to thermoset repair patch 212 to compress thermoset repair patch 212. In some illustrative examples, pressure 244 of approximately 60 psi to 90 psi is applied to thermoset repair patch 212 while thermoset repair patch 212 is heated to bond thermoset repair patch 212 to thermoplastic composite part 202. In some illustrative examples, pressure 244 of approximately 85 psi is applied to thermoset repair patch 212 while thermoset repair patch 212 is heated to bond thermoset repair patch 212 to thermoplastic composite part 202. In some illustrative examples, pressure 244 is removed from thermoset repair patch 212 after thermoset repair patch 212 is allowed to cool to ambient temperature.

[0040] In some illustrative examples, after repair patch 208 is adhered to thermoplastic composite part 202, the ends of heating element 206 may extend outside of repair patch 208. In some illustrative examples, after repair patch 208 is adhered to thermoplastic composite part 202, the ends of heating element 206 extend from thermoplastic composite part 202. As shown, end 246 and end 248 of heating element 206 extend from between repair patch 208 and thermoplastic composite part 202. As shown, trimming the ends of heating element 206 may include trimming end 246 and end 248.

[0041] Figure 2 The illustration of manufacturing environment 200 in FIG. 1 is not meant to imply physical or architectural limitations to the manner in which the illustrative embodiments may be implemented. Components other than or in place of the components shown may be used. Some components may not be necessary. Furthermore, the block diagrams are presented to illustrate some functional components. When implemented in the illustrative embodiments, one or more of these block diagrams may be combined, divided, or combined and divided into different block diagrams.

[0042] For example, in some illustrative examples, there may be additional heating elements and additional repair patches. In some illustrative examples, there may be a corresponding heating element and a corresponding repair patch on either side of non-conforming region 232 of thermoplastic composite part 202 in the thickness direction.

[0043] Now turn Figure 3 , depicts a cross-sectional view of a repair of a thermoplastic composite part according to an illustrative embodiment. The thermoplastic composite part 302 is Figure 2 300, a heating element 306 has been placed over a repair region 304 of thermoplastic composite component 302. In this illustrative example, repair region 304 comprises a portion of thermoplastic composite component 302 after the non-conforming region has been removed from thermoplastic composite component 302. In this illustrative example, a series of composite material layers have been cut from thermoplastic composite component 302 to create repair region 304.

[0044] In this illustrative example, heating element 306 has been placed over repair area 304 and heated to adhere heating element 306 to thermoplastic composite part 302. After heating element 306 has been adhered to thermoplastic composite part 302, repair patch 308 is placed over heating element 306. Heating element 306 is used to heat repair patch 308 to a patch processing temperature. The patch processing temperature is selected based on the material type of repair patch 308.

[0045] Repair patch 308 is previously laid up adjacent to the layers of thermoplastic composite part 302 that were removed to create repair area 304. In some illustrative examples, repair patch 308 may be referred to as a scarf patch. When repair patch 308 is placed in contact with thermoplastic material 312 of heating element 306, repair patch 308 is in a cured state.

[0046] Heating element 306 is impregnated with thermoplastic material 312. Heating element 306 includes carbon conductive material 310 and thermoplastic material 312. Thermoplastic material 312 is the portion of heating element 306 that adheres to repair area 304 of thermoplastic composite part 302. Carbon conductive material 310 is the portion of heating element 306 that generates heat in response to flowing an electrical current into heating element 306.

[0047] Now turn Figure 4 , depicts a cross-sectional view of a repair of a thermoplastic composite part according to an illustrative embodiment. The thermoplastic composite part 402 is Figure 2 4 shows a physical implementation of thermoplastic composite part 202. In illustration 400, heating element 406 has been placed on repair region 405 of thermoplastic composite part 402. In this illustrative example, repair region 405 comprises a portion of surface 407 of thermoplastic composite part 402. In this illustrative example, inconsistent region 404 is present in thermoplastic composite part 402. Repair region 405 is a portion of surface 407 above inconsistent region 404 in thermoplastic composite part 402.

[0048] In this illustrative example, heating element 406 has been placed over repair area 405 and heated to adhere heating element 406 to repair area 405 of thermoplastic composite part 402. After heating element 406 has been adhered to thermoplastic composite part 402, repair patch 408 is placed over heating element 406. Heating element 406 is used to heat repair patch 408 to a patch processing temperature. The patch processing temperature is selected based on the material type of repair patch 408.

[0049] Repair patch 408 is placed over inconsistent area 404 without removing inconsistent area 404 from thermoplastic composite part 402. In some illustrative examples, repair patch 408 may be referred to as a doubler. Repair patch 408 may be used to repair inconsistent areas that do not extend through the thickness of thermoplastic composite part 402.

[0050] Heating element 406 is impregnated with thermoplastic material 412. Heating element 406 includes carbon conductive material 410 and thermoplastic material 412. Thermoplastic material 412 is the portion of heating element 406 that adheres to thermoplastic composite part 402. Carbon conductive material 410 is the portion of heating element 406 that generates heat in response to flowing current into heating element 406.

[0051] Now turn Figure 5 , depicts a cross-sectional view of a repair of a thermoplastic composite part according to an illustrative embodiment. The thermoplastic composite part 502 is Figure 2 500 , heating element 506 has been placed on repair region 505 of thermoplastic composite component 502. In illustration 500 , heating element 516 has been placed on repair region 514 of thermoplastic composite component 502. In this illustrative example, repair region 505 and repair region 514 are on a surface of thermoplastic composite component 502. In this illustrative example, repair region 505 comprises a portion of surface 507 of thermoplastic composite component 502. In this illustrative example, inconsistent region 504 exists in thermoplastic composite component 502. Repair region 505 is a portion of surface 507 above inconsistent region 504 in thermoplastic composite component 502.

[0052] In this illustrative example, repair region 514 includes a portion of surface 515 of thermoplastic composite part 502. In this illustrative example, repair region 514 is a portion of surface 515 at inconsistent region 504 in thermoplastic composite part 502.

[0053] In this illustrative example, heating element 506 has been placed over repair area 505 and heated to adhere heating element 506 to repair area 505 of thermoplastic composite part 502. After heating element 506 has been adhered to thermoplastic composite part 502, repair patch 508 is placed over heating element 506. Heating element 506 is used to heat repair patch 508 to a patch processing temperature. The patch processing temperature is selected based on the material type of repair patch 508.

[0054] Heating element 506 is impregnated with thermoplastic material 512. Heating element 506 includes carbon conductive material 510 and thermoplastic material 512. Thermoplastic material 512 is the portion of heating element 506 that adheres to thermoplastic composite part 502. Carbon conductive material 510 is the portion of heating element 506 that generates heat in response to flowing current into heating element 506.

[0055] In this illustrative example, heating element 516 has been placed over repair area 514 and heated to adhere heating element 516 to repair area 514 of thermoplastic composite part 502. After heating element 516 has been adhered to thermoplastic composite part 502, repair patch 518 is placed over heating element 516. Heating element 516 is used to heat repair patch 518 to a patch processing temperature. The patch processing temperature is selected based on the material type of repair patch 518.

[0056] Heating element 516 is impregnated with thermoplastic material 522. Heating element 516 includes carbon conductive material 520 and thermoplastic material 522. Thermoplastic material 522 is the portion of heating element 516 that adheres to thermoplastic composite part 502. Carbon conductive material 520 is the portion of heating element 516 that generates heat in response to flowing current into heating element 516.

[0057] Now turn Figure 6 , depicts a cross-sectional view of a repair of a thermoplastic composite part according to an illustrative embodiment. The thermoplastic composite part 602 is Figure 2 6. In illustration 600, a heating element 608 has been placed on a repair area 606 of thermoplastic composite component 602. In this illustrative example, thermoplastic composite component 602 is a reinforcement. Thermoplastic composite component 602 is a reinforcement bonded to thermoplastic composite skin 601.

[0058] In this illustrative example, repair region 606 comprises a portion of surface 605 of thermoplastic composite part 602. In this illustrative example, inconsistent region 604 is present in thermoplastic composite part 602. Repair region 606 is a portion of surface 605 above inconsistent region 604 in thermoplastic composite part 602.

[0059] In this illustrative example, heating element 608 has been placed over repair area 606 and heated to adhere heating element 608 to repair area 606 of thermoplastic composite part 602. After heating element 608 has been adhered to thermoplastic composite part 602, repair patch 610 is placed over heating element 608. Heating element 608 is used to heat repair patch 610 to a patch processing temperature. The patch processing temperature is selected based on the material type of repair patch 610.

[0060] Repair patch 610 is placed over inconsistent area 604 without removing inconsistent area 604 from thermoplastic composite part 602. In some illustrative examples, repair patch 610 may be referred to as an external reinforcer. Repair patch 610 may be used to repair inconsistent areas that do not extend through the thickness of thermoplastic composite part 602.

[0061] Heating element 608 is impregnated with thermoplastic material 614. Heating element 608 includes carbon conductive material 612 and thermoplastic material 614. Thermoplastic material 614 is the portion of heating element 608 that adheres to thermoplastic composite part 602. Carbon conductive material 612 is the portion of heating element 608 that generates heat in response to flowing current into heating element 608.

[0062] Now turn Figure 7A and Figure 7B , a flow chart depicting a method of repairing a thermoplastic composite part according to an illustrative embodiment. The method 700 may be performed to repair a Figure 1 The method 700 may be performed to repair a thermoplastic composite component of the aircraft 100. Figure 2 Thermoplastic composite part 202. The method 700 may be performed to repair Figure 3 Thermoplastic composite part 302. The method 700 may be performed to repair Figure 4 Thermoplastic composite part 402. The method 700 may be performed to repair Figure 5 Thermoplastic composite part 502. The method 700 may be performed to repair Figure 6 Thermoplastic composite part 602 .

[0063] Method 700 places a heating element impregnated with a thermoplastic material onto a repair region of a thermoplastic composite part (operation 702). The repair region can take any desired form. In some illustrative examples, the repair region is a surface above a non-conforming region. In some illustrative examples, the repair region is created by removing the non-conforming region from the thermoplastic composite part. The repair region can have any desired size or shape.

[0064] Method 700 adheres the thermoplastic material of the heating element to the repair area by generating heat in the heating element from an electric current applied to the heating element (operation 704). After adhering the heating element to the repair area, method 700 places a repair patch on the heating element (operation 706). Method 700 applies an electric current to the heating element to heat the repair patch to a patch processing temperature (operation 708). Thereafter, method 700 terminates.

[0065] In some illustrative examples, method 700 removes a portion of a thermoplastic composite component to form a repair region (operation 710). In some illustrative examples, the removed portion of the thermoplastic composite component includes an inconsistent region. In some illustrative examples, removing the portion of the thermoplastic composite component includes iteratively removing layers of the thermoplastic composite component. In some illustrative examples, removing the portion of the thermoplastic composite component includes removing a miter section from the thermoplastic composite component.

[0066] In some illustrative examples, method 700 treats the surface of the repair area prior to applying the heating element, where the treating includes cleaning and polishing the repair area (operation 712). In these illustrative examples, treating the surface includes treating the surface without using a high-energy pretreatment (preparation). In these illustrative examples, treating the surface includes treating the surface without requiring a plasma treatment.

[0067] In some illustrative examples, method 700 applies compression to the repair patch while heating the repair patch to a patch processing temperature to bond the repair patch to the thermoplastic composite part (operation 714). The compression is sufficient to process the material of the repair patch during heating.

[0068] In some illustrative examples, the repair patch comprises a thermoplastic repair patch (operation 716). In some illustrative examples, the patch processing temperature is approximately 280° C. to 340° C. (operation 718). In some illustrative examples, the patch processing temperature is approximately 310° C. In some illustrative examples, the method 700 applies a pressure of approximately 15 psi to 45 psi to the repair patch while heating the repair patch to bond the repair patch to the thermoplastic composite part (operation 720). In some illustrative examples, the method 700 applies a pressure of approximately 30 psi to the repair patch while heating the repair patch to bond the repair patch to the thermoplastic composite part. In some illustrative examples, the method 700 removes the pressure from the repair patch after allowing the repair patch to cool to 150° C. (operation 722).

[0069] In some illustrative examples, method 700 trims an end of the heating element extending from the thermoplastic composite part (operation 724 ). In some illustrative examples, the end of the heating element extending beyond the repair patch is trimmed. In some illustrative examples, the trimmed end is exposed.

[0070] In some illustrative examples, the repair patch comprises a thermoset repair patch (operation 726). In some illustrative examples, the patch processing temperature is approximately 170° C. to 190° C. (operation 728). In some illustrative examples, the patch processing temperature is approximately 180° C. In some illustrative examples, the method 700 applies a pressure of approximately 60 psi to 90 psi to the repair patch while heating the repair patch to bond the repair patch to the thermoplastic composite part (operation 730). In some illustrative examples, the method 700 applies a pressure of approximately 85 psi to the repair patch while heating the repair patch to bond the repair patch to the thermoplastic composite part. In some illustrative examples, the method 700 removes pressure from the repair patch after allowing the repair patch to cool to ambient temperature (operation 732).

[0071] Now turn Figure 8, a flow chart depicting a method of repairing a thermoplastic composite part according to an illustrative embodiment. The method 800 may be performed to repair Figure 1 The method 800 may be performed to repair a thermoplastic composite component of an aircraft 100. Figure 2 Thermoplastic composite part 202. The method 800 may be performed to repair Figure 3 Thermoplastic composite part 302. The method 800 may be performed to repair Figure 4 Thermoplastic composite part 402. The method 800 may be performed to repair Figure 5 Thermoplastic composite part 502. The method 800 may be performed to repair Figure 6 Thermoplastic composite part 602 .

[0072] Method 800 places a heating element impregnated with a thermoplastic material onto a repair area of a thermoplastic composite part (operation 802). Method 800 adheres the thermoplastic material of the heating element to the repair area by generating heat in the heating element from an electric current applied to the heating element (operation 804). After adhering the heating element to the repair area, method 800 places a thermoplastic repair patch onto the heating element (operation 806). Method 800 heats the thermoplastic repair patch to a patch processing temperature using the heating element (operation 808). Method 800 applies pressure to the thermoplastic repair patch while heating the repair patch (operation 810). Method 800 then terminates.

[0073] In some illustrative examples, method 800 treats the surface of the repair area prior to applying the heating element, where the treating includes cleaning and polishing the repair area (operation 812). In these illustrative examples, treating the surface includes treating the surface without using a high-energy pretreatment. In these illustrative examples, treating the surface includes treating the surface without requiring a plasma treatment.

[0074] In some illustrative examples, the patch treatment temperature is between 280° C. and 340° C. (operation 814). In some illustrative examples, the patch treatment temperature is approximately 310° C. In some illustrative examples, the pressure is between 15 psi and 45 psi (operation 816). In some illustrative examples, the pressure is approximately 30 psi. In some illustrative examples, method 800 removes the pressure from the repair patch after allowing the repair patch to cool to 150° C. (operation 818).

[0075] In some illustrative examples, method 800 trims an end of the heating element extending from the thermoplastic composite component (operation 820). After applying the repair patch, the heating element remains in the thermoplastic composite component. The heating element remains in the thermoplastic composite component during operation of a platform (such as an aircraft) containing the thermoplastic composite component. In some illustrative examples, the heating element is trimmed so that the end extends beyond the repair patch. In some illustrative examples, the trimmed end is exposed after the repair patch is adhered to the thermoplastic composite component.

[0076] Now turn Figure 9 , a flow chart depicting a method of repairing a thermoplastic composite part according to an illustrative embodiment. The method 900 may be performed to repair Figure 1 The method 900 may be performed to repair a thermoplastic composite component of an aircraft 100. Figure 2 Thermoplastic composite part 202. The method 900 may be performed to repair Figure 3 Thermoplastic composite part 302. The method 900 may be performed to repair Figure 4 Thermoplastic composite part 402. The method 900 may be performed to repair Figure 5 Thermoplastic composite part 502. The method 900 may be performed to repair Figure 6 Thermoplastic composite part 602 .

[0077] Method 900 places a heating element impregnated with a thermoplastic material onto a repair area of a thermoplastic composite part (operation 902). Method 900 adheres the thermoplastic material of the heating element to the repair area by generating heat in the heating element from an electric current applied to the heating element (operation 904). After adhering the heating element to the repair area, method 900 places a thermoset repair patch onto the heating element (operation 906). Method 900 heats the thermoset repair patch to a patch processing temperature using the heating element (operation 908). Method 900 applies pressure to the repair patch while heating the thermoset repair patch (operation 910). Method 900 then terminates.

[0078] In some illustrative examples, method 900 treats the surface of the repair area prior to applying the heating element, where the treating includes cleaning and sanding the repair area (operation 912). In these illustrative examples, treating the surface includes treating the surface without using a high-energy pretreatment. In these illustrative examples, treating the surface includes treating the surface without requiring a plasma treatment.

[0079] In some illustrative examples, the patch processing temperature is approximately 170° C. to 190° C. (operation 914). In some illustrative examples, the patch processing temperature is approximately 180° C. In some illustrative examples, the method 900 applies a pressure of approximately 60 psi to 90 psi to the repair patch while heating the repair patch to bond the repair patch to the thermoplastic composite part (operation 916). In some illustrative examples, the method 900 applies a pressure of approximately 85 psi to the repair patch while heating the repair patch to bond the repair patch to the thermoplastic composite part. In some illustrative examples, the method 900 removes the pressure from the repair patch after allowing the repair patch to cool to ambient temperature (operation 918).

[0080] In some illustrative examples, method 900 trims an end of the heating element extending from the thermoplastic composite component (operation 920). After applying the repair patch, the heating element remains in the thermoplastic composite component. The heating element remains in the thermoplastic composite component during operation of a platform (such as an aircraft) containing the thermoplastic composite component. In some illustrative examples, the end of the heating element extending beyond the repair patch is trimmed. In some illustrative examples, the trimmed end is exposed.

[0081] Now turn Figure 10 , a flow chart depicting a method of repairing a thermoplastic composite part according to an illustrative embodiment. The method 1000 may be performed to repair a Figure 1 The method 1000 may be performed to repair a thermoplastic composite component of an aircraft 100. Figure 2 Thermoplastic composite part 202. The method 1000 may be performed to repair Figure 3 Thermoplastic composite part 302. The method 1000 may be performed to repair Figure 4 Thermoplastic composite part 402. The method 1000 may be performed to repair Figure 5 Thermoplastic composite part 502. The method 1000 may be performed to repair Figure 6 Thermoplastic composite part 602 .

[0082] Method 1000 adheres the low-melting thermoplastic material of the heating element to the repair area of the thermoplastic composite part (operation 1002). Method 1000 adheres the low-melting thermoplastic material to the repair patch (operation 1004). Thereafter, method 1000 terminates.

[0083] In some illustrative examples, method 1000 removes a portion of the thermoplastic composite component to form a repair region (operation 1006). In some illustrative examples, the removed portion of the thermoplastic composite component includes an inconsistent region. In some illustrative examples, removing the portion of the thermoplastic composite component includes iteratively removing layers of the thermoplastic composite component. In some illustrative examples, removing the portion of the thermoplastic composite component includes removing a miter section from the thermoplastic composite component.

[0084] In some illustrative examples, adhering the low-melting thermoplastic material to the repair area includes heating a heating element by applying an electric current to the heating element (operation 1008). In some illustrative examples, the electric current applied to the heating element heats a carbon conductive material in the heating element. In some illustrative examples, adhering the low-melting thermoplastic material to the repair patch includes heating the heating element by applying an electric current to the heating element (operation 1010).

[0085] In some illustrative examples, method 1000 applies compression to the repair patch while heating the repair patch to a patch processing temperature to bond the repair patch to the thermoplastic composite part (operation 1012 ). The amount of compression is selected based on the material type of the repair patch.

[0086] In some illustrative examples, the repair patch comprises a thermoplastic repair patch (operation 1014). In some other illustrative examples, the repair patch comprises a thermoset repair patch (operation 1016). The thermoplastic material in the heating element used for the thermoplastic repair patch will be different from the thermoplastic material in the heating element used for the thermoset repair patch. Additionally, the processing temperature and pressure of the repair patch will be different for the thermoplastic repair patch and the thermoset repair patch.

[0087] In some illustrative examples, method 1000 trims ends of the heating element that extend from the thermoplastic composite component (operation 1018). After applying the repair patch, the heating element remains in the thermoplastic composite component. The heating element remains in the thermoplastic composite component during operation of a platform (such as an aircraft) containing the thermoplastic composite component. Any ends of the heating element that extend beyond the thermoplastic composite component are trimmed.

[0088] The present disclosure relates to non-limiting examples defined in the following terms.

[0089] Clause 1. A method 700 of repairing a thermoplastic composite part 202, 302, 402, 502, 602, the method comprising:

[0090] placing 702 a heating element 206 , 306 , 406 , 506 , 516 , 608 impregnated 226 with a thermoplastic material 218 , 312 , 412 , 512 , 522 , 614 onto the repair area 204 , 304 , 405 , 505 , 514 , 606 of the thermoplastic composite part 202 , 302 , 402 , 502 , 602 ;

[0091] adhering 704 the thermoplastic material 218 , 312 , 412 , 512 , 522 , 614 of the heating element 206 , 306 , 406 , 506 , 516 , 608 to the repair area 204 , 304 , 405 , 505 , 514 , 606 by generating heat in the heating element 206 , 306 , 406 , 506 , 516 , 608 from an electric current 223 applied to the heating element 206 , 306 , 406 , 506 , 516 , 608 ;

[0092] placing 706 a repair patch 208, 308, 408, 508, 518, 610 on the heating element 206, 306, 406, 506, 516, 608 after adhering the heating element 206, 306, 406, 506, 516, 608 to the repair area 204, 304, 405, 505, 514, 606; and

[0093] An electric current 223 is applied 708 to the heating element 206 , 306 , 406 , 506 , 516 , 608 to heat the repair patch 208 , 308 , 408 , 508 , 518 , 610 to a patch processing temperature 238 , 242 .

[0094] Clause 2. The method 700 of clause 1, further comprising:

[0095] Compression is applied 714 to the repair patch 208 , 308 , 408 , 508 , 518 , 610 while the repair patch 208 , 308 , 408 , 508 , 518 , 610 is heated to the patch processing temperature 238 , 242 to bond the repair patch 208 , 308 , 408 , 508 , 518 , 610 to the thermoplastic composite part 202 , 302 , 402 , 502 , 602 .

[0096] Clause 3. The method 700 of clause 1, further comprising:

[0097] A portion 230 of the thermoplastic composite part 202 , 302 , 402 , 502 , 602 is removed 710 to form the repair region 204 , 304 , 405 , 505 , 514 , 606 .

[0098] Clause 4. The method 700 of Clause 1, wherein the repair patch 208 , 308 , 408 , 508 , 518 , 610 comprises a thermoplastic repair patch 210 .

[0099] Clause 5. The method 700 of Clause 4, wherein the patch processing temperature 238 is approximately 280°C to 340°C.

[0100] Clause 6. The method 700 of clause 5, further comprising:

[0101] A pressure 240 of about 15 psi to 45 psi is applied 720 to the repair patch 208 , 308 , 408 , 508 , 518 , 610 while heating the repair patch 208 , 308 , 408 , 508 , 518 , 610 to bond the repair patch 208 , 308 , 408 , 508 , 518 , 610 to the thermoplastic composite part 202 , 302 , 402 , 502 , 602 .

[0102] Clause 7. The method 700 of clause 6, further comprising:

[0103] The pressure 240 is removed 722 from the repair patch 208 , 308 , 408 , 508 , 518 , 610 after allowing the repair patch 208 , 308 , 408 , 508 , 518 , 610 to cool to 150° C.

[0104] Clause 8. The method 700 of Clause 1, wherein the repair patch 208 , 308 , 408 , 508 , 518 , 610 comprises a thermoset repair patch 212 .

[0105] Clause 9. The method 700 of Clause 8, wherein the patch processing temperature 242 is approximately 170°C to 190°C.

[0106] Clause 10. The method 700 of clause 9, further comprising:

[0107] A pressure 244 of about 60 psi to 90 psi is applied 730 to the repair patch 208 , 308 , 408 , 508 , 518 , 610 while heating the repair patch 208 , 308 , 408 , 508 , 518 , 610 to bond the repair patch 208 , 308 , 408 , 508 , 518 , 610 to the thermoplastic composite part 202 , 302 , 402 , 502 , 602 .

[0108] Clause 11. The method 700 of clause 10, further comprising:

[0109] After allowing the repair patch 208 , 308 , 408 , 508 , 518 , 610 to cool to ambient temperature, the pressure 244 is removed 732 from the repair patch 208 , 308 , 408 , 508 , 518 , 610 .

[0110] Clause 12. The method 700 of clause 1, further comprising:

[0111] The ends 246 , 248 of the heating elements 206 , 306 , 406 , 506 , 516 , 608 extending from the thermoplastic composite part 202 , 302 , 402 , 502 , 602 are trimmed 724 .

[0112] Clause 13. The method 700 of clause 1, further comprising:

[0113] The surface 228 , 407 , 507 , 515 , 605 of the repair area 204 , 304 , 405 , 505 , 514 , 606 is treated 712 before applying the heating element 206 , 306 , 406 , 506 , 516 , 608 , wherein the treatment comprises cleaning and grinding the repair area 204 , 304 , 405 , 505 , 514 , 606 .

[0114] Clause 14. A method 800 of repairing a thermoplastic composite part 202, 302, 402, 502, 602, the method comprising:

[0115] placing 802 a heating element 206 , 306 , 406 , 506 , 516 , 608 impregnated 226 with a thermoplastic material 218 , 312 , 412 , 512 , 522 , 614 onto the repair area 204 , 304 , 405 , 505 , 514 , 606 of the thermoplastic composite part 202 , 302 , 402 , 502 , 602 ;

[0116] adhering 804 the thermoplastic material 218 , 312 , 412 , 512 , 522 , 614 of the heating element 206 , 306 , 406 , 506 , 516 , 608 to the repair area 204 , 304 , 405 , 505 , 514 , 606 by generating heat in the heating element 206 , 306 , 406 , 506 , 516 , 608 from an electric current 223 applied to the heating element 206 , 306 , 406 , 506 , 516 , 608 ;

[0117] placing 806 a thermoplastic repair patch 210 on the heating element 206 , 306 , 406 , 506 , 516 , 608 after adhering the heating element 206 , 306 , 406 , 506 , 516 , 608 to the repair area 204 , 304 , 405 , 505 , 514 , 606 ;

[0118] heating 808 the thermoplastic repair patch 210 to a patch processing temperature 238 , 242 using the heating element 206 , 306 , 406 , 506 , 516 , 608 ; and

[0119] Pressure 240 is applied 810 to the thermoplastic repair patch 210 while the thermoplastic repair patch 210 is heated.

[0120] Clause 15. The method 800 of Clause 14, wherein the patch processing temperature 238 is 280°C to 340°C.

[0121] Clause 16. The method 800 of Clause 14, wherein the pressure 240 is between 15 psi and 45 psi.

[0122] Clause 17. The method 800 of clause 16, further comprising:

[0123] The pressure 240 is removed 818 from the thermoplastic repair patch 210 after allowing the thermoplastic repair patch 210 to cool to 150°C.

[0124] Clause 18. The method 800 of clause 14, further comprising:

[0125] The surface 228 , 407 , 507 , 515 , 605 of the repair area 204 , 304 , 405 , 505 , 514 , 606 is treated 812 before applying the heating element 206 , 306 , 406 , 506 , 516 , 608 , wherein the treatment comprises cleaning and grinding the repair area 204 , 304 , 405 , 505 , 514 , 606 .

[0126] Clause 19. The method 800 of clause 14, further comprising:

[0127] The ends 246 , 248 of the heating elements 206 , 306 , 406 , 506 , 516 , 608 extending from the thermoplastic composite part 202 , 302 , 402 , 502 , 602 are trimmed 820 .

[0128] Clause 20. A method 900 of repairing a thermoplastic composite part 202, 302, 402, 502, 602, the method comprising:

[0129] placing 902 a heating element 206 , 306 , 406 , 506 , 516 , 608 impregnated 226 with a thermoplastic material 218 , 312 , 412 , 512 , 522 , 614 onto the repair area 204 , 304 , 405 , 505 , 514 , 606 of the thermoplastic composite part 202 , 302 , 402 , 502 , 602 ;

[0130] adhering 904 the thermoplastic material 218 , 312 , 412 , 512 , 522 , 614 of the heating element 206 , 306 , 406 , 506 , 516 , 608 to the repair area 204 , 304 , 405 , 505 , 514 , 606 by generating heat in the heating element 206 , 306 , 406 , 506 , 516 , 608 from an electric current 223 applied to the heating element 206 , 306 , 406 , 506 , 516 , 608 ;

[0131] placing 906 a thermosetting repair patch 212 on the heating element 206 , 306 , 406 , 506 , 516 , 608 after adhering the heating element 206 , 306 , 406 , 506 , 516 , 608 to the repair area 204 , 304 , 405 , 505 , 514 , 606 ;

[0132] heating 908 the thermosetting repair patch 212 to a patch processing temperature 238 , 242 using the heating element 206 , 306 , 406 , 506 , 516 , 608 ; and

[0133] Pressure 244 is applied 910 to the thermoset repair patch 212 while the thermoset repair patch 212 is heated.

[0134] Clause 21. The method 900 of Clause 20, wherein the patch processing temperature 238, 242 is approximately 170°C to 190°C.

[0135] Clause 22. The method 900 of clause 20, further comprising:

[0136] A pressure 244 of approximately 60 psi to 90 psi is applied 916 to the thermoset repair patch 212 while the thermoset repair patch 212 is heated to bond the thermoset repair patch 212 to the thermoplastic composite part 202 , 302 , 402 , 502 , 602 .

[0137] Clause 23. The method 900 of clause 22, further comprising:

[0138] The pressure 244 is removed 918 from the thermoset repair patch 212 after allowing the thermoset repair patch 212 to cool to ambient temperature.

[0139] Clause 24. The method 900 of clause 20, further comprising:

[0140] The surface 228 , 407 , 507 , 515 , 605 of the repair area 204 , 304 , 405 , 505 , 514 , 606 is treated 912 before applying the heating element 206 , 306 , 406 , 506 , 516 , 608 , wherein the treatment comprises cleaning and grinding the repair area 204 , 304 , 405 , 505 , 514 , 606 .

[0141] Clause 25. The method 900 of clause 20, further comprising:

[0142] The ends 246 , 248 of the heating elements 206 , 306 , 406 , 506 , 516 , 608 extending from the thermoplastic composite part 202 , 302 , 402 , 502 , 602 are trimmed 920 .

[0143] Clause 26. A method 1000 of repairing a thermoplastic composite part 202, 302, 402, 502, 602, the method comprising:

[0144] adhering 1002 the low melting point 220 thermoplastic material 218 , 312 , 412 , 512 , 522 , 614 of the heating element 206 , 306 , 406 , 506 , 516 , 608 to the repair area 204 , 304 , 405 , 505 , 514 , 606 of the thermoplastic composite part 202 , 302 , 402 , 502 , 602 ; and

[0145] The low melting point 220 thermoplastic material 218 , 312 , 412 , 512 , 522 , 614 is adhered 1004 to the repair patch 208 , 308 , 408 , 508 , 518 , 610 .

[0146] Clause 27. The method 1000 of clause 26, further comprising:

[0147] Compression is applied 1012 to the repair patch 208 , 308 , 408 , 508 , 518 , 610 while the repair patch 208 , 308 , 408 , 508 , 518 , 610 is heated to the patch processing temperature 238 , 242 to bond the repair patch 208 , 308 , 408 , 508 , 518 , 610 to the thermoplastic composite part 202 , 302 , 402 , 502 , 602 .

[0148] Clause 28. The method 1000 of clause 26, further comprising:

[0149] A portion 230 of the thermoplastic composite part 202 , 302 , 402 , 502 , 602 is removed 1006 to form the repair region 204 , 304 , 405 , 505 , 514 , 606 .

[0150] Clause 29. The method 1000 of Clause 26, wherein the repair patch 208, 308, 408, 508, 518, 610 comprises a thermoplastic repair patch 210.

[0151] Clause 30. The method 1000 of Clause 26, wherein the repair patch 208, 308, 408, 508, 518, 610 comprises a thermoset repair patch 212.

[0152] Clause 31. The method 1000 of clause 26, further comprising:

[0153] The ends 246 , 248 of the heating elements 206 , 306 , 406 , 506 , 516 , 608 extending from the thermoplastic composite part 202 , 302 , 402 , 502 , 602 are trimmed 1018 .

[0154] Clause 32. The method 1000 of clause 26, wherein adhering the low-melting-point 220 thermoplastic material 218, 312, 412, 512, 522, 614 to the repair area 204, 304, 405, 505, 514, 606 comprises heating the heating element 206, 306, 406, 506, 516, 608 by applying an electric current 223 to the heating element 206, 306, 406, 506, 516, 608.

[0155] Clause 33. The method 1000 of clause 26, wherein adhering the low melting point 220 thermoplastic material 218, 312, 412, 512, 522, 614 to the repair patch 208, 308, 408, 508, 518, 610 comprises heating the heating element 206, 306, 406, 506, 516, 608 by applying an electric current 223 to the heating element 206, 306, 406, 506, 516, 608.

[0156] As used herein, the phrase "at least one of...", when used with a list of items, means that different combinations of one or more of the listed items may be used, and only one item from each item in the list may be required. For example, "at least one of Item A, Item B, or Item C" may include, but is not limited to, Item A, Item A and Item B, or Item B. This example may also include Item A, Item B, and Item C, or Item B and Item C. Of course, any combination of these items may be present. In other examples, "at least one of..." may be, for example, but not limited to, two of Item A; one of Item B; and ten of Item C; four of Item B and seven of Item C; or other suitable combinations. The items may be specific objects, things, or categories. In other words, "at least one of..." means that any combination of items and numbers of items from the list may be used, but not all items in the list are required.

[0157] As used herein, "a plurality," when used with reference to items, means one or more items.

[0158] The flowcharts and block diagrams in the depicted different embodiments illustrate the architecture, functionality, and operation of some possible implementations of the devices and methods in the illustrative embodiments. In this regard, each box in the flowchart or block diagram can represent at least one of a module, a segment, a function, an operation, or a portion of a step.

[0159] In some alternative implementations of the illustrative embodiments, one or more functions indicated in the blocks may not occur in the order indicated in the accompanying drawings. For example, in some cases, two blocks shown in succession may be executed substantially simultaneously, or the blocks may sometimes be executed in the reverse order, depending on the functions involved. Furthermore, in addition to the blocks shown in the flowchart or block diagram, other blocks may be added. Some blocks may be optional. For example, operations 710 to 732 may be optional. For example, operations 812 to 820 may be optional. For example, operations 912 to 920 may be optional.

[0160] You can Figure 11 Aircraft manufacturing and service method 1100 is shown and Figure 12 Illustrative embodiments of the present disclosure are described in the context of the illustrated aircraft 1200. Figure 11 , an illustration of an aircraft manufacturing and service method in the form of a block diagram is depicted in accordance with an illustrative embodiment. During pre-production, aircraft manufacturing and service method 1100 may include Figure 12 Specification and design 1102 of the aircraft 1200 and material procurement 1104.

[0161] During production, component and subassembly manufacturing 1106 and system integration 1108 of aircraft 1200 occurs. Thereafter, aircraft 1200 may undergo certification and delivery 1110 for entry into service 1112. While in operation 1112 by a customer, aircraft 1200 is scheduled for routine maintenance and service 1114, which may include modification, reconfiguration, refurbishment, or other maintenance and service.

[0162] Each of the processes of aircraft manufacturing and service method 1100 may be performed or executed by a system integrator, a third party, and / or an operator. In these examples, the operator may be a customer. For purposes of this description, a system integrator may include, but is not limited to, any number of aircraft manufacturers and major system subcontractors; a third party may include, but is not limited to, any number of vendors, subcontractors, and suppliers; and an operator may include, but is not limited to, an airline, a leasing company, a military entity, a service organization, and the like.

[0163] Now refer to Figure 12 , depicts a diagram of an aircraft in block diagram form in which the illustrative embodiments may be implemented. In this example, aircraft 1200 is Figure 11 Aircraft manufacturing and service method 1100 is produced and may include airframe 1202 having multiple systems 1204 and interior 1206. Examples of systems 1204 include one or more of propulsion system 1208, electrical system 1210, hydraulic system 1212, and environmental system 1214. Any number of other systems may be included.

[0164] Apparatus and methods embodied herein may be employed during at least one of the stages of aircraft manufacturing and service method 1100. Figure 11 One or more illustrative embodiments are manufactured or used during at least one of component and subassembly manufacturing 1106 , system integration 1108 , operation 1112 , or maintenance and service 1114 .

[0165] The illustrative example uses a heating element comprised of a thermoplastic material to bond a repair patch to a thermoplastic component having an inconsistency. The illustrative example enables the use of either a thermoplastic repair patch or a thermoset repair patch without requiring surface pretreatment of the thermoplastic component. The heating element in the bond line provides localized heating to the bond area. The heating element can heat from room temperature to the desired bonding temperature at a very fast rate (150°C / min).

[0166] Illustrative examples provide methods for performing structural repairs on thermoplastic components during production and operation. The illustrative examples utilize a low-melting-temperature thermoplastic material in a heating element to bond a repair patch to a thermoplastic composite component. The repair patch can be a thermoplastic composite patch or a thermoset composite patch. Depending on the material of the repair patch, different thermoplastic films are used.

[0167] The illustrative examples eliminate the need for surface pretreatment other than cleaning or grinding to apply the repair patch. The illustrative examples eliminate the need for surface pretreatment (including high-energy pretreatment, such as plasma treatment) to apply the repair patch. The illustrative examples eliminate the use of conventional structural adhesives to bond the repair patch to the thermoplastic composite part. The illustrative examples utilize a heating element between the repair patch and the thermoplastic composite part to provide localized heating to bond them. The use of the heating element improves efficiency and enables repairs to be performed on aircraft in service. Different thermoplastic formulations for the heating element enable repairs to be performed with either thermoplastic or thermoset patches.

[0168] The description of the various illustrative embodiments has been presented for purposes of illustration and description, and is not intended to be exhaustive or limited to the embodiments in the disclosed form. Many modifications and variations will be apparent to those skilled in the art. Furthermore, different illustrative embodiments may provide different features than other illustrative embodiments. The selected embodiment or embodiments are chosen and described in order to best explain the principles of the embodiments, their practical application, and to enable those skilled in the art to understand the disclosure of various embodiments with various modifications suitable for the specific intended use.

Claims

1. A method (700) of repairing a thermoplastic composite part (202, 302, 402, 502, 602), the method comprising: placing (702) a heating element (206, 306, 406, 506, 516, 608) impregnated (226) with a thermoplastic material (218, 312, 412, 512, 522, 614) onto a repair area (204, 304, 405, 505, 514, 606) of a thermoplastic composite part (202, 302, 402, 502, 602); adhering (704) the thermoplastic material (218, 312, 412, 512, 522, 614) of the heating element (206, 306, 406, 506, 516, 608) to the repair area (204, 304, 405, 505, 514, 606) by generating heat in the heating element (206, 306, 406, 506, 516, 608) from an electric current (223) applied to the heating element (206, 306, 406, 506, 516, 608); placing (706) a repair patch (208, 308, 408, 508, 518, 610) over the heating element (206, 306, 406, 506, 516, 608) after adhering the heating element (206, 306, 406, 506, 516, 608) to the repair area (204, 304, 405, 505, 514, 606); and An electric current (223) is applied (708) to the heating element (206, 306, 406, 506, 516, 608) to heat the repair patch (208, 308, 408, 508, 518, 610) to a patch processing temperature (238, 242).

2. The method (700) of claim 1, further comprising: Compression is applied (714) to the repair patch (208, 308, 408, 508, 518, 610) while heating the repair patch (208, 308, 408, 508, 518, 610) to the patch processing temperature (238, 242) to bond the repair patch (208, 308, 408, 508, 518, 610) to the thermoplastic composite part (202, 302, 402, 502, 602).

3. The method (700) of claim 1, further comprising: A portion (230) of the thermoplastic composite part (202, 302, 402, 502, 602) is removed (710) to form the repair region (204, 304, 405, 505, 514, 606).

4. The method (700) of claim 1, wherein: The repair patch (208, 308, 408, 508, 518, 610) comprises a thermoplastic repair patch (210).

5. The method (700) of claim 4, wherein: The patch processing temperature (238) is 280°C to 340°C.

6. The method (700) of claim 5, further comprising: Applying (720) a pressure (240) of 15 psi to 45 psi to the repair patch (208, 308, 408, 508, 518, 610) while heating the repair patch (208, 308, 408, 508, 518, 610) to bond the repair patch (208, 308, 408, 508, 518, 610) to the thermoplastic composite part (202, 302, 402, 502, 602).

7. The method (700) of claim 6, further comprising: The pressure (240) is removed (722) from the repair patch (208, 308, 408, 508, 518, 610) after allowing the repair patch (208, 308, 408, 508, 518, 610) to cool to 150°C.

8. A method (800) of repairing a thermoplastic composite part (202, 302, 402, 502, 602), the method comprising: placing (802) a heating element (206, 306, 406, 506, 516, 608) impregnated (226) with a thermoplastic material (218, 312, 412, 512, 522, 614) onto a repair area (204, 304, 405, 505, 514, 606) of a thermoplastic composite part (202, 302, 402, 502, 602); adhering (804) the thermoplastic material (218, 312, 412, 512, 522, 614) of the heating element (206, 306, 406, 506, 516, 608) to the repair area (204, 304, 405, 505, 514, 606) by generating heat in the heating element (206, 306, 406, 506, 516, 608) from an electric current (223) applied to the heating element (206, 306, 406, 506, 516, 608); placing (806) a thermoplastic repair patch (210) over the heating element (206, 306, 406, 506, 516, 608) after adhering the heating element (206, 306, 406, 506, 516, 608) to the repair area (204, 304, 405, 505, 514, 606); heating (808) the thermoplastic repair patch (210) to a patch processing temperature (238, 242) using the heating element (206, 306, 406, 506, 516, 608); as well as Pressure (240) is applied (810) to the thermoplastic repair patch (210) while the thermoplastic repair patch (210) is heated.

9. A method (900) of repairing a thermoplastic composite part (202, 302, 402, 502, 602), the method comprising: placing (902) a heating element (206, 306, 406, 506, 516, 608) impregnated (226) with a thermoplastic material (218, 312, 412, 512, 522, 614) onto a repair area (204, 304, 405, 505, 514, 606) of a thermoplastic composite part (202, 302, 402, 502, 602); adhering (904) the thermoplastic material (218, 312, 412, 512, 522, 614) of the heating element (206, 306, 406, 506, 516, 608) to the repair area (204, 304, 405, 505, 514, 606) by generating heat in the heating element (206, 306, 406, 506, 516, 608) from an electric current (223) applied to the heating element (206, 306, 406, 506, 516, 608); placing (906) a thermosetting repair patch (212) over the heating element (206, 306, 406, 506, 516, 608) after adhering the heating element (206, 306, 406, 506, 516, 608) to the repair area (204, 304, 405, 505, 514, 606); heating (908) the thermosetting repair patch (212) to a patch processing temperature (238, 242) using the heating element (206, 306, 406, 506, 516, 608); as well as Pressure (244) is applied (910) to the thermosetting repair patch (212) while the thermosetting repair patch (212) is heated.

10. A method (1000) of repairing a thermoplastic composite part (202, 302, 402, 502, 602), the method comprising: Adhering (1002) the low melting point (220) thermoplastic material (218, 312, 412, 512, 522, 614) of the heating element (206, 306, 406, 506, 516, 608) to the repair area (204, 304, 405, 505, 514, 606) of the thermoplastic composite part (202, 302, 402, 502, 602); and The low melting point (220) thermoplastic material (218, 312, 412, 512, 522, 614) is adhered (1004) to the repair patch (208, 308, 408, 508, 518, 610).

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