Blanket heating system and method of reworking an aircraft

Abstract

The present disclosure relates to a heat blanket system comprising: a blanket comprising a first sub-region and a second sub-region; and a plurality of heating elements printed on the blanket, wherein: a first spacing between first heating elements of the plurality of heating elements in the first sub-region varies relative to a second spacing between second heating elements of the plurality of heating elements in the second sub-region, the first spacing and the second spacing varying according to a design configured for a uniquely defined rework region on a uniquely defined composite object, the composite object comprising a third region and a fourth region, the third region comprising a heat spreader region, the fourth region comprising a non-heat spreader region, the first sub-region being sized and dimensioned to be placed on the third region, and the second sub-region being sized and dimensioned to be placed on the fourth region, and a method of reworking an aircraft.

Description

[0001] This application is a divisional application of application number 202110463875.5 filed on April 27, 2021, entitled "Heated Blanket System and Method of Manufacturing the Heated Blanket System", the entire contents of which are incorporated herein by reference. Technical Field

[0002] One or more embodiments are in the field of composite material reprocessing, and more specifically in the field of heating blankets for reprocessing composite materials. Background Technology

[0003] Inconsistencies can sometimes occur in composite materials. “Inconsistency” is defined as any measurable characteristic of a composite material that is outside the predetermined specification engineering tolerances.

[0004] Composite materials can be reprocessed to remove or mitigate non-compliance. "Reprocessing" a composite material is defined as any process performed on it to remove or mitigate non-compliance. The term "mitigating non-compliance" is defined as bringing a composite material object to predetermined engineering tolerances.

[0005] Reprocessing composites may involve adding liquid composite resins, prepreg tapes (“prepreg” is a pre-impregnated composite fiber in which a thermosetting polymer matrix material, such as epoxy or thermoplastic resin, is already present), composite patches, or some other pre-cured composite to areas of inconsistency. The pre-cured material is then bonded to the matrix structure, using a film or paste adhesive to mitigate the inconsistency. As part of the curing process, the pre-cured composite and adhesive are heated.

[0006] In some cases, heating blankets can be used to achieve heating. However, when the pre-cured composite material has varying thicknesses, or is placed on a component within an object that serves as a heat sink, uneven heating may occur within the pre-cured composite material. Uneven heating can produce inconsistencies during curing. Summary of the Invention

[0007] One or more embodiments provide a method. The method includes receiving a digital model of at least a portion of a composite structure having inconsistencies. The digital model includes a pre-calculated heating model specifying multiple regions of inconsistency, for which different amounts of heat are applied to an uncured composite material with corresponding inconsistencies. The method also includes generating a design based on the digital model for heating elements with varying densities across regions. The design is configured such that heating elements in a first sub-region of a heated blanket system generate first heat in a third region of the region. The design is further configured such that heating elements in a second sub-region of the heated blanket system generate second heat in a fourth region of the region. The first heat is different from the second heat. The method also includes printing the heating elements onto a blanket according to the design to manufacture the heated blanket system.

[0008] One or more embodiments also include a heated blanket system. The heated blanket system includes a blanket comprising a first sub-region and a second sub-region. The heated blanket system also includes heating elements printed on the blanket. A first spacing between the first heating elements in the first sub-region varies relative to a second spacing between the second heating elements in the second sub-region. The first and second spacings vary according to a design. The design is configured for a uniquely defined reprocessing area on a uniquely defined composite material object, the composite material object including a third region and a fourth region, the third region including a radiator region and the fourth region including a non-radiator region. The size and dimensions of the first sub-region are configured to be positioned on the third region. The size and dimensions of the second sub-region are configured to be positioned on the fourth region.

[0009] One or more embodiments also provide a method for reprocessing an aircraft comprising a composite material having regions including inconsistencies. The method includes fabricating the aircraft for reprocessing by preparing the composite material in the regions of inconsistency. The method further includes generating a digital model of the regions of inconsistency, wherein the digital model includes a heating model of sub-regions specifying the regions of inconsistency, for which different amounts of heating are applied to uncured composite material applied to the inconsistencies. The method further includes generating a design based on the digital model for heating elements with varying densities across sub-regions. The design is configured to generate a first heat in a first sub-region of the sub-regions. The design is further configured to generate a second heat in a second sub-region of the sub-regions. The first heat is different from the second heat. The method further includes printing the heating elements onto a blanket using a 3D printer to manufacture a heating blanket according to the design. The method further includes applying an uncured composite patch to the regions of inconsistency. The method further includes applying a heating blanket to the uncured composite patch. The method further includes curing the uncured composite patch by applying differential heating to the uncured composite patch using the heating blanket.

[0010] Other aspects of the invention will become apparent from the following description and the appended claims. Attached Figure Description

[0011] Figure 1 A heated blanket system disposed on a reprocessing area according to one or more embodiments is shown; Figure 2 A method for manufacturing and using an on-demand printed thermal blanket system according to one or more embodiments is illustrated; Figure 3 A method for reprocessing an aircraft using an on-demand printed thermal blanket system is illustrated according to one or more embodiments; Figure 4 A cross-section of a composite material object including a reprocessed region is shown according to one or more embodiments; Figure 5 A system for generating on-demand printed thermal blankets according to one or more embodiments is shown; Figure 6 Specific examples and methods of using an on-demand printed thermal blanket system according to one or more embodiments are shown; Figure 7 An illustration is provided according to one or more embodiments. Figure 6 The application of the on-demand printed thermal blanket system is shown in a specific example. Figure 8 An aircraft panel having a reworked area with inconsistencies, according to one or more embodiments, is shown; Figure 9 An illustration is provided according to one or more embodiments. Figure 8 Another view of the aircraft's control panel; Figure 10 An illustration is provided according to one or more embodiments. Figure 8 The cross-section of the aircraft panel; Figure 11 The following are examples illustrating the use of one or more embodiments for generating Figure 8 The heating model shown is part of the heating simulation process of the panel. Figure 12 The following are examples illustrating the use of one or more embodiments for generating Figure 8 The heating model of the panel shown is part of the process. Figure 11 Another part of the heating simulation; Figure 13 An illustration is provided according to one or more embodiments. Figure 8 The heating model of the panel shown; Figure 14A A diagram illustrating a source according to one or more embodiments is provided. Figure 13 The heat density map of the heating blanket generated by the heating model in the image; Figure 14B A diagram illustrating a source according to one or more embodiments is provided. Figure 13 The heat density map of the heating blanket generated by the heating model in the image; Figure 15 Methods for manufacturing and maintaining an aircraft according to one or more embodiments are shown; and Figure 16 An aircraft according to one or more embodiments is shown. Detailed Implementation

[0012] Specific embodiments of the invention will now be described in detail with reference to the accompanying drawings. For consistency, the same elements in the various drawings are indicated by the same reference numerals.

[0013] In the following detailed description of embodiments of the invention, numerous specific details are set forth in order to provide a more thorough understanding of the invention. However, it will be apparent to those skilled in the art that the invention can be practiced without these specific details. In other instances, well-known features have not been described in detail to avoid unnecessarily complicating the description.

[0014] Throughout the application, ordinal numbers (e.g., first, second, third, etc.) may be used as adjectives for elements (i.e., any noun in the application). Unless explicitly disclosed, the use of ordinal numbers does not imply or create any particular order of elements or limit any element to a single element, such as through the use of terms like “before,” “after,” “single,” and other such terms. Rather, the use of ordinal numbers is to distinguish between elements. As an example, a first element is distinct from a second element, and a first element may contain more than one element, and the elements are listed in order after (or before) the second element.

[0015] When used with respect to measurable physical properties, the term "approximately" refers to an engineering tolerance anticipated or determined by an engineer or manufacturing technician skilled in the art. The precise quantification of an engineering tolerance depends on the product being manufactured and the technical performance being measured. For a non-limiting example, two angles may be "approximately equal" if their values ​​are within ten percent of each other. However, if an engineer determines that the engineering tolerance for a particular product should be more stringent, "approximately equal" may mean that the values ​​of two angles are within one percent of each other. Similarly, in other embodiments, engineering tolerances may be relaxed such that the values ​​of angles that are "approximately equal" are within twenty percent of each other. In the example of temperature differences, "approximately uniform temperature" refers to a temperature range approximately ideal for a particular application. Thus, in a more specific but non-limiting example, assuming a temperature variation of 10 degrees Fahrenheit in different regions of a composite material is within a predetermined engineering tolerance, "approximately uniform temperature" may be 200 degrees Fahrenheit ± 10 degrees Fahrenheit across the entire composite material. In any case, a person skilled in the art can assess acceptable engineering tolerances for a particular product and therefore can assess how to determine the measurement variance contemplated by the term "approximately".

[0016] Typically, embodiments of the present invention relate to on-demand printed heat blanket systems specifically designed to cure specific uncured composite patches or other uncured composite materials applied to specific areas of a particular object made of the composite material for reprocessing. In other words, one or more embodiments provide heat blanket systems and methods for manufacturing and using them, specifically tailored for reprocessing specific inconsistencies on a particular composite material object.

[0017] As used herein, a “heated blanket system” is defined as a blanket, a specified pattern of heating elements disposed on or within the blanket, and any other components attached to the blanket (such as, but not limited to, leads, circuitry, power supplies, transformers, etc.). One or more embodiments of a “heated blanket system” provide a “heated blanket system” having a custom array of heating elements (i.e., specifically designed for a particular reprocessing project) and any components attached to the blanket.

[0018] Heating blankets (such as, but not limited to, electric blankets) are used to heat and cure composite patches and other composite materials. Heating blankets are available from suppliers in various sizes and are typically round or rectangular.

[0019] Purchasing prefabricated, off-the-shelf heating blankets can present challenges when reprocessing areas of complex objects, such as parts of an aircraft. One challenge is the significant variation in size and shape inconsistencies. Technicians can attempt to predict which blanket size will facilitate the reprocessing of various inconsistencies. However, technicians can significantly modify the reprocessing approach based on the size and shape of available blankets. If the available blankets are unsuitable for the application, new blankets must be ordered. Typical lead times for custom-made heating blankets can be a month or longer. In the case of aircraft reprocessing, delays can result in lost aircraft service time, which in turn directly translates into lost revenue and profits for aircraft operators.

[0020] Another challenge of using off-the-shelf heating blankets is that such blankets have heating elements spaced evenly across the entire blanket. Therefore, off-the-shelf heating blankets produce a uniform heat output or watt density across the area of ​​the blanket. Consequently, when the blanket is energized, it radiates the same amount of heat across its surface. A challenge associated with uniform heating is that many aircraft refinishing projects will not have uniform heat requirements. For example, skin thickness can vary across multiple sections of the aircraft where inconsistencies are located. Furthermore, inconsistencies can be located on integrated reinforcements or honeycomb cores beneath certain sections of the aircraft skin where the inconsistencies are located. Therefore, while off-the-shelf heating blankets radiate a uniform amount of heat across the refinished area, the temperature will undesirably vary significantly across the cured refinished area (e.g., cooler under the reinforcement and warmer where the skin is thinner). However, most refinishing processes specify that the curing temperature be maintained within a predetermined threshold throughout the composite patch. For example, the temperature difference across the entire composite patch can be specified to be maintained within 10 degrees Fahrenheit above or below the curing temperature. In other words, the desired outcome is not for the blanket to radiate a uniform amount of heat, but for the composite patch to maintain a uniformly elevated temperature throughout the entire composite patch, regardless of the thickness variations of the patch or the presence of a heat sink in the underlying structure.

[0021] To mitigate uneven patch temperatures, local insulation can be placed on a vacuum bag to heat areas within the patch below a predetermined temperature threshold. The challenge of using local insulation is the continuous monitoring and management of insulation and curing throughout the curing process. Insulation is added or removed throughout the curing process to prevent the thermocouple from becoming too hot or too cold. Therefore, the monitoring process is cumbersome and error-prone. Errors may result in the need to redo the entire rework project. Redoing a rework project is undesirable in terms of both cost and time. In some cases, when errors occur, parts being reworked may have to be discarded, further increasing costs and rework time.

[0022] One or more embodiments address these and other challenges by providing a print-on-demand (POD) heating blanket system specifically tailored for a particular reprocessing project. The POD heating blanket system distributes uneven heat across the dimensions of the POD heating blanket system to compensate for composite patch areas that require more or less heat to maintain a temperature difference threshold within the composite patch. Reprocessing areas requiring additional heating receive additional heat through a higher heating element density due to increased patch thickness or the presence of a heat sink in the underlying composite part. Conversely, reprocessing areas requiring less heating will receive less heat through a lower heating element density due to reduced patch thickness or the absence of a heat sink in the underlying composite part.

[0023] The term "heating element density" is defined as a measurement of the spacing or distance between heating elements. Therefore, for example, a first blanket with a higher heating element density than a second blanket will have more heating elements per inch than a second blanket.

[0024] The POD heating blanket system, according to one or more embodiments, offers several benefits. The POD heating blanket system achieves improved curing by maintaining a more uniform heating temperature throughout the reprocessing area, i.e., by avoiding unwanted temperature variations in the reprocessing area. The POD heating blanket system can be manufactured in the workshop where the reprocessing project is performed, thereby increasing the speed of the reprocessing process and reducing aircraft downtime. The POD heating blanket system reduces costs by allowing technicians to manufacture or procure specific heating blanket systems for particular reprocessing projects, rather than purchasing many off-the-shelf heating blankets of different shapes and sizes for selective use in different reprocessing projects.

[0025] Now let’s turn our attention to the attached figures. Figure 1A heating blanket system disposed on a reprocessing area according to one or more embodiments is shown. The heating blanket system (100) may be placed, covered, or otherwise disposed on a reprocessing area (102) of a composite material object (104). The reprocessing area (102) is a portion of the composite material object (104) to be reprocessed. The reprocessing area (102) may be larger or smaller than inconsistencies (not shown) in or on the composite material object (104). In many cases, the reprocessing area (102) is larger than the inconsistencies.

[0026] The heating blanket system (100) is divided into multiple sub-regions, including a first sub-region (106) and a second sub-region (108). Each sub-region is part of the heating blanket system (100). Each sub-region may be part of a continuous material forming the heating blanket system (100), or may be discontinuous with some parts of the heating blanket system (100).

[0027] The heating blanket system (100) itself is a substrate that can be formed from a variety of materials, such as paper, polyethylene terephthalate (PET), or poly(4,4'-oxophenylene-pyromellitictetramethylimide) (which is sold by DuPont Company under the trademark KAPTON®) or other polymer films. As further described below, additional materials such as heating elements, thermal sensors, thermocouples, etc., are added to the substrate. Additional layers may also be added to the substrate. For example, either side of the substrate may be laminated with one or more dielectric layers or films to provide electrical insulation for any electronic components disposed on the substrate. Thus, a first side of the substrate may have a first dielectric layer or insulating layer, and a second side of the substrate may have a second dielectric layer or insulating layer disposed opposite to the first side of the substrate. Optionally, the heating blanket against a side with inconsistent placement may be a single-sided adhesive film. This option allows the blanket to be placed directly on a reprocessed surface without the need for the typically present additional release film layer.

[0028] Each sub-region of the heating blanket system (100) is designed to be placed on a specific area of ​​the composite object (104) in the reprocessing area (102). Thus, for example, a first sub-region (106) of the heating blanket system (100) covers a third region (110) of the reprocessing area (102). Similarly, for example, a second sub-region (108) of the heating blanket system (100) covers a fourth region (112) of the reprocessing area (102).

[0029] The heating element can be placed on the heating blanket system (100) by various methods, such as deposition or printing. Printing methods include, but are not limited to, 3D printing, inkjet printing, screen printing, atomized jet deposition, plasma flame spraying, etc. The heating element can be a resistance heating element, such as conductive or resistive ink, or it can be some other type of heating element, such as a fluid tube.

[0030] Each sub-zone of the heated blanket system (100) may have a different set of heating elements. For example, the third zone (110) of the heated blanket system (100) may have a first heating element (114) thereon. Similarly, the fourth zone (112) of the heated blanket system (100) may have a second heating element (116) thereon.

[0031] Each group of heating elements may have different spacing between the individual heating elements. Thus, for example, the first heating element (114) may have a first spacing (118). Similarly, the second heating element (116) may have a second spacing (120). As used herein, “spacing” refers to the distance between the individual heating elements. In this example, the first spacing (118) is smaller than the second spacing (120). Therefore, the density of the first heating element (114) is greater than the density of the second heating element (116).

[0032] Therefore, the total heat generated by the first heating element (114) in the first sub-region (106) of the third region (110) is greater than the total heat generated by the second heating element (116) in the second sub-region (108) of the fourth region (112). However, due to the different heating requirements in the third region (110) relative to the fourth region (112), the temperature variation within the reprocessing region (102) will generally remain within the threshold temperature range. Figure 1 In the arrangement shown, the third region (110) of the reprocessing region (102) is a heat sink region, and the second sub-region (108) of the reprocessing region (102) is a non-heat sink region.

[0033] The spacing of the heating elements is part of a design based on a thermal model generated for the reworked region (102) of the composite object (104). The thermal model is a mapping indicating how much heat should be applied to any given portion of the reworked region (102) to maintain the reworked region (102) within a threshold temperature difference. Therefore, in this example, more heat is applied to the third region (110) relative to the fourth region (112) to maintain the desired threshold temperature difference across the entire reworked region (102) during the curing of the composite patch (see [link to relevant documentation]). Figure 7 ).

[0034] about Figure 13An example of a thermal model is shown. The thermal model (1300) can be used to generate the design of a heated blanket system (100), which will be used in manufacturing. Figure 1 The illustrated heating blanket system (100) is shown. Specifically, the design specifies a first spacing (118) for the third zone (110) and a second spacing (120) for the second sub-zone (108). The design may also specify the type and shape of the heating elements used. The design may also specify the shape of the individual zones and / or heating elements of the heating blanket system (100). Therefore, although Figure 1 Rectangular, uniformly spaced heating elements and regions are shown, but the shape and size of the third region (110), the fourth region (112), the first heating element (114), and the second heating element (116) can vary according to the heating predicted by the thermal model (1300) for each uniquely defined sub-region of the reprocessing region (102).

[0035] Therefore, one or more embodiments provide a heating blanket system (100) having a first sub-region (106) and a second sub-region (108). Heating elements are printed on the heating blanket system (100). A first spacing (118) between the first heating elements (first heating element (114)) in the first sub-region (106) varies relative to a second spacing (120) between the second heating elements (second heating element (116)) in the second sub-region (108). The first spacing (118) and the second spacing (120) vary according to a design. The design is configured for a uniquely defined reprocessing area on a uniquely defined composite material object (104) including a third region (110) and a fourth region (112), the third region (110) including a radiator region and the fourth region (112) including a non-radiator region. In other embodiments, this arrangement may be reversed or changed. The size and dimensions of the first sub-region (106) are set to be placed on the third region (110). The size and dimensions of the second sub-region (108) are set to be placed on the fourth region (112). The first spacing (118) can be smaller than the second spacing (120), or vice versa.

[0036] The heated blanket system (100) may be provided with additional features. For example, the heated blanket system (100) may include one or more thermal sensors, such as a first thermal sensor (122) and a second thermal sensor (124). Each thermal sensor may be a thermistor, a thermometer, or any other thermal sensor suitable for printing or depositing on the heated blanket system (100).

[0037] Each thermal sensor senses heat in a specific area of ​​the reprocessing area (102). Thus, for example, the first thermal sensor (122) can sense a first temperature in a third area (110) of the reprocessing area (102). Similarly, the second thermal sensor (124) can sense a second temperature in a fourth area (112) of the reprocessing area (102).

[0038] Other features may also be provided. For example, perforations (126) may be provided through selected portions of the heating blanket system (100). In one embodiment, the perforations (126) are provided to vent gases emitted by the cured composite material in the reprocessing zone (102). In some embodiments, the perforations may affect the heating applied to the various areas in the reprocessing zone (102). The thermal model (1300) may account for such heating variations (if significant) and the spacing of the heating elements in the various areas of the heating blanket system (100) may be modified accordingly.

[0039] The perforations (126) can have various shapes and sizes and can be arranged in different areas of the heating blanket system (100) with different densities (spacing) relative to each other. Thus, for example, the first perforation (128) is shown as a circle, while the second perforation (130) is shown as a square, and other perforations (132) are shown as circles smaller than the first perforation (128). Although the perforations (126) are shown outside the first sub-region (106) and the second sub-region (108) of the heating blanket system (100), the perforations (126) can be arranged within the first sub-region (106) and / or the second sub-region (108) or other parts of the heating blanket system (100).

[0040] Additional features may be added to the heating blanket system (100). For example, control circuitry (134) may be printed or otherwise deposited on the heating blanket system (100). The control circuitry (134) may be an application-specific integrated circuit (ASIC) or other circuitry specifically designed for the heating blanket system (100) in the rework area (102). The control circuitry (134) may be used to control or modify the power delivered to the first heating element (114) and / or the second heating element (116) based on signals received by a wireless transmitter, such as signals received from a remote computer. The control circuitry (134) may also be used to monitor the first thermal sensor (122) and the second thermal sensor (124) and / or calculate the temperature difference measured by the first thermal sensor (122) and the second thermal sensor (124).

[0041] The control circuit (134) can also control other devices printed or otherwise disposed on the heating blanket system (100). For example, an alarm device (136) may be printed or otherwise disposed on the heating blanket system (100). The control circuit (134) may be programmed to trigger the alarm device (136) to sound an alarm when the temperature difference measured by the first thermal sensor (122) and the second thermal sensor (124) exceeds a threshold. The alarm may take the form of an audio alarm, a visual cue (such as a flashing light-emitting diode (LED)), etc.

[0042] In another example, the wireless transmitter (138) may be printed or otherwise disposed on the heating blanket system (100). The wireless transmitter (138) may transmit temperature measurements generated by the first thermal sensor (122) and / or the second thermal sensor (124). The wireless transmitter (138) may also send an alarm to a remote computer when the control circuit (134) determines that the temperature difference between the first thermal sensor (122) and the second thermal sensor (124) exceeds a threshold.

[0043] The wireless transmitter (138) can also communicate with a computer (140). The computer (140) can be programmed to monitor and / or control various characteristics of the heating blanket system (100), including the power supply (142) described below. For example, the computer (140) can record temperature measurements from a first thermal sensor (122) and / or a second thermal sensor (124). The computer (140) can replace some functions of the control circuitry (134), such as monitoring differences between the measurements from the first thermal sensor (122) and the second thermal sensor (124), or generating alarms. (See also: Regarding...) Figures 8 to 14B As illustrated in the example, the computer (140) may also be the same computer that generates the design of the thermal model (1300) and / or the heating element. In some embodiments, the computer (140) may be miniaturized and directly mounted on the heating blanket system (100), possibly replacing the control circuitry (134).

[0044] As described above, the first heating element (114) and the second heating element (116) are powered by a power source (142). When the heating element is a resistance heating element, the power source (142) can be an electrical power source. When the heating element is a pipe or capillary through which a heating fluid can flow, the power source (142) can be a liquid heat source. In some embodiments, the power source (142) is connected to a junction (not shown) printed or otherwise disposed on the heating blanket system (100) and in communication with the heating element. In other embodiments, the power source (142) can be printed or otherwise disposed directly on the heating blanket system (100). The power source (142) can be a single power source, such as electricity or heating fluid, or it can be multiple power sources. In the case of an electrical power source (142), the power source (142) can provide a constant current to both the first heating element (114) and the second heating element (116).

[0045] As an alternative embodiment, the first heating element (114) and the second heating element (116) may have the same or different spacing as shown. In this case, such as when the power source (142) is an electrical power source, different currents can be applied to the first heating element (114) and / or the second heating element (116). Thus, differential heating can be achieved by changing the power supplied to the heating elements rather than changing the spacing between the heating elements.

[0046] As an optional embodiment, the heating element may include additional features, such as a self-regulating positive thermal coefficient feature. Some printable heating materials have the ability to self-regulate to a predetermined temperature. In this way, computer control or feedback may not be used to maintain the desired temperature within the heating blanket system (100) and / or the patch.

[0047] The heated blanket system (100) can be equipped with additional features. Therefore, although Figure 1 The component configurations are shown, but other configurations can be used without departing from the scope of the invention. For example, various components can be combined to create a single component. As another example, the functionality performed by a single component can be performed by two or more components. Regarding Figures 4 to 7 Additional, more specific exemplary variations are described.

[0048] Figure 2 A method for manufacturing and using an on-demand printed thermal blanket system according to one or more embodiments is illustrated. It can be used... Figure 1 The heated blanket system (100) shown is used to achieve this. Figure 2 The method is shown. In some embodiments, the steps shown by the dashed lines may be considered optional.

[0049] Such as about Figure 2The "manufacturing system" described herein is defined as the entity that performs the individual steps. "Manufacturing system" refers to the computers, printing presses, and other hardware used to manufacture the heated blanket system. Therefore, "manufacturing system" can include... Figure 5 The computer (500) and Figure 5 A three-dimensional printing machine (506). In each step, appropriate features of the manufacturing system perform specified actions. Thus, for example, although Figure 2 The description refers to a "manufacturing system" that performs the steps of receiving a digital model, but the actual receiving steps can be performed by a computer (500). In another example, the "manufacturing system" that performs the printing steps could refer to... Figure 5 The actions performed by the three-dimensional printer (506) shown.

[0050] In step 200, the manufacturing system receives a digital model of at least a portion of a composite structure exhibiting inconsistencies. This digital model includes a pre-calculated heating model specifying multiple regions of inconsistency, for which different amounts of heat are applied to the uncured composite material to represent the inconsistencies. Thus, for example, a computer can receive both a digital model of the composite structure and the accompanying pre-calculated heating model. Regarding Figure 13 An example of a heating model is shown, and in Figure 6 and Figure 14B An example design for a heated blanket system is shown. In some embodiments, the computer can also generate a digital model.

[0051] In step 202, the manufacturing system generates a design for heating elements with varying densities across regions based on a digital model. This design is configured to generate a first heat source in a first sub-region of the region. The design is further configured to generate a second heat source in a second sub-region of the region. The first heat source differs from the second heat source to accommodate the different heating requirements in the different sub-regions of the reprocessing area.

[0052] In step 204, the manufacturing system prints heating elements onto the blanket according to the design to manufacture a heated blanket system. The distinction between the terms “blanket” (in itself) and “heated blanket system” is that a “heated blanket system” is a “blanket” after the heating elements designed according to one or more embodiments, as well as any other components attached to or in the blanket, have been printed onto the blanket.

[0053] Printing can be accomplished using a 3D printer loaded with resistive ink or other printing materials. It can also be accomplished using deposition, screen printing, inkjet printing, atomized jet deposition, plasma flame spraying, paste deposition, and other techniques. Other technologies can also be used to deposit or otherwise place heating elements on the blanket.

[0054] This can be terminated. Figure 2The method. However, in other embodiments, Figure 2 The method can include more steps.

[0055] For example, in step 206, the manufacturing system can print a thermal sensor onto a corresponding area of ​​the heating blanket system. A 3D printer can be used to print the thermal sensor. However, a pre-fabricated thermal sensor can also be attached to the heating blanket system. Other devices (such as, but not limited to, control circuitry, alarm devices, wireless transmitters, etc.) can also be printed onto the heating blanket system in this step (or other steps).

[0056] In another example, in step 208, the manufacturing system reprocesses the inconsistency by applying uncured composite material to the inconsistency. The uncured composite material can be applied by a robot using a composite patch or liquid resin to the inconsistent area. Reprocessing may include removing some or all of the composite material from the inconsistent area. In some cases, the inconsistency can be reprocessed manually.

[0057] In step 210, the manufacturing system places the heating blanket system onto the uncured composite material after reprocessing. Robotic or human technicians can place the heating blanket system on the inconsistency so that appropriate sub-regions of the heating blanket system cover the corresponding modeled areas of the reprocessed area.

[0058] In step 212, the manufacturing system cures the uncured composite material by generating heat through a heating element. For example, a control circuit or computer can be used to apply electricity to the resistance heating element. In this case, the method may also include connecting the resistance heating element to an electrical power source and applying electricity to the resistance heating element. If the heating element is a tube, a pump can be used to pump heated liquid through the heating element.

[0059] In step 214, the manufacturing system monitors the corresponding temperature in the area using a thermal sensor. For example, a control circuit or computer can monitor the temperature readings acquired by the thermal sensor and then calculate the difference between the temperature readings.

[0060] In step 216, the manufacturing system then determines whether the temperature difference exceeds a threshold. The threshold may vary depending on the specific process, but in this example, the temperature difference threshold may be 10 degrees Fahrenheit (i.e., the temperature difference between any two measurements across the reprocessing area is less than or equal to 10 degrees Fahrenheit).

[0061] If the temperature difference threshold is exceeded (determined as "Yes" in step 216), the system can generate an alarm in step 218. Specifically, an alarm is generated when a first temperature in a first sub-region of the zone exceeds a second temperature in a second sub-region that exceeds the threshold temperature difference. This alarm can be an audio, visual, or audible / visual alarm informing a technician that the temperature difference has exceeded the threshold. Therefore, the technician can take action to reduce the temperature difference across the reprocessing zones. Otherwise (determined as "No" in step 216), processing proceeds to step 220.

[0062] In step 220, it is determined whether the composite structure has cured. If it has not cured (determined as "No" in step 220), the process returns to step 214 for monitoring and repetition. If curing is complete (determined as "Yes" in step 220), the process terminates.

[0063] Figure 3 A method for reprocessing an aircraft using an on-demand printed thermal blanket system is shown according to one or more embodiments. Figure 3 The method can be characterized as a method for reprocessing aircraft, which includes composite materials having regions of inconsistency. It can be used... Figure 1 The heated blanket system (100) shown and / or Figure 5 The apparatus shown is used to implement this. Figure 3 The method shown. Figure 3 The method can be considered Figure 2 Variations of the method shown. In some embodiments, Figure 3 The steps shown by the dashed lines are optional.

[0064] Such as about Figure 3 The "manufacturing system" described herein is defined as the entity that performs the individual steps. "Manufacturing system" refers to the computers, printing presses, and other hardware used to manufacture the heated blanket system. Therefore, "manufacturing system" can include... Figure 5 The computer (500) and Figure 5 A three-dimensional printing machine (506). In each step, appropriate features of the manufacturing system perform specified actions. Thus, for example, although Figure 3 The description refers to a "manufacturing system" that performs the steps of receiving a digital model, but the actual receiving steps can be performed by a computer (500). In another example, the "manufacturing system" that performs the printing steps could refer to... Figure 5 The actions performed by the three-dimensional printer (506) shown.

[0065] In step 300, the manufacturing system fabricates the aircraft for reprocessing by preparing composite materials in areas of inconsistency. The fabrication of the aircraft for reprocessing can be performed by a robot or a technician. The aircraft can be fabricated by scarifying or abrading the composite material in the reprocessing area, scribing the reprocessing area, or completely removing a portion of the composite material from the reprocessing area. Aircraft fabrication may also include creating or sourcing composite patches to be placed in or on the reprocessing area, and / or placing liquid resin or prepreg tape on the reprocessing area.

[0066] In step 302, the manufacturing system generates a digital model of the inconsistency area. This digital model includes heating models of sub-regions specifying the inconsistency area, for which different amounts of heat are applied to the uncured composite material where the inconsistency is located. An example of the heating model is shown below. Figure 13 As shown.

[0067] In step 304, the manufacturing system generates a design for a heating element with varying density across sub-regions based on the digital model. This design is configured to cause the heating element to generate a first amount of heat in a first sub-region of the sub-region. The design is further configured to cause the heating element to generate a second amount of heat in a second sub-region of the sub-region. The first amount of heat is different from the second amount of heat. (Regarding...) Figures 8 to 13 This describes an example of generating a design for a heating element based on a digital model.

[0068] In step 306, the manufacturing system uses a 3D printer to print the heating element onto the blanket according to the design to manufacture the heated blanket system. The distinction between the terms “blanket” (in itself) and “heated blanket system” is that after the heating element designed according to one or more embodiments, as well as any other components attached to or in the blanket, have been printed onto the blanket, the “heated blanket system” is the “blanket”.

[0069] Optionally, in step 308, the manufacturing system may print a first thermal sensor and a second thermal sensor onto the heating blanket system as part of the heating blanket manufacturing system. The first thermal sensor is printed onto the heating blanket system to measure a first temperature in a first sub-region of the reprocessing area. The second thermal sensor is printed onto the heating blanket system to measure a second temperature in a second sub-region of the reprocessing area. Printing can be performed using a 3D printer, such as... Figure 5 As shown.

[0070] In step 310, the manufacturing system applies the uncured composite patch to the inconsistent areas. This application can be performed by a robot or a human technician. The patch is an uncured composite material. In some embodiments, a liquid composite resin or prepreg tape may be used instead of the patch. One or more embodiments contemplate that the liquid composite resin or prepreg tape is considered equivalent to the “patch” used in one or more embodiments.

[0071] In step 312, the manufacturing system applies the heating blanket system to the uncured composite patch. The application of the heating blanket system can be performed by a robot or manually by a human technician.

[0072] In step 314, the manufacturing system cures the uncured composite patch by applying differential heating to the uncured composite patch using a heat blanket system. Differential heating can be achieved by applying a uniform current to different subsets of resistance heating elements with varying densities. Alternatively, differential heating can be achieved by applying different current levels to different subsets of resistance heating elements printed on the heat blanket system.

[0073] Optionally, in step 316, the manufacturing system can monitor the corresponding temperature in a sub-region of the reprocessing area using thermal sensors printed on the thermal blanket system. For example, the system can measure a first temperature using a first thermal sensor during curing. The system can also measure a second temperature using a second thermal sensor during curing. The system can then determine the difference between the first and second temperatures and monitor the difference over time.

[0074] In step 318, the manufacturing system can determine whether the temperature difference exceeds a temperature difference threshold. If the temperature difference exceeds the threshold (determined as "yes" in step 318), then in step 320, the system can generate an alarm. If an alarm is generated, optionally, a robot or technician can take action to mitigate the difference between the first and second temperatures. Actions may include temporarily suspending heating of some or all reprocessing areas, adding or removing insulation from some or all reprocessing areas (above or below the heating blanket system), adjusting the amount of power delivered to the heating blanket system, adjusting the flow rate of heating liquid sent through the heating element tubes, or various other possible actions.

[0075] return Figure 3 Regardless of whether an alarm is generated in step 320 (e.g., if "No" is confirmed in step 318 or after an alarm is generated in step 320), it is then determined in step 322 whether the composite patch has been cured. If the composite patch has not yet been cured (if "No" is confirmed in step 322), the method returns to step 316 and repeats. Otherwise (if "Yes" is confirmed in step 322), Figure 3 The method terminates.

[0076] Although presented and described in sequence Figure 2 and Figure 3 The flowchart shown illustrates the various steps, but those skilled in the art will understand that some or all steps may be performed in a different order, may be combined or omitted, and some or all steps may be performed in parallel. Furthermore, these steps may be performed actively or passively.

[0077] Figures 4 to 7 The following examples are for illustrative purposes only and are not intended to limit the scope of the invention. They should be considered together. Figures 4 to 7 .

[0078] Figure 4 A cross-section of a composite material object including a reprocessed region is shown according to one or more embodiments. Figure 4 As shown, a composite part (400) is being reprocessed. The composite part (400) includes a reprocessed area (402) where inconsistencies exist. Since a portion of the reprocessed area (402) has been removed from the composite part (400), the inconsistencies are not addressed in the reprocessed area. Figure 4 As shown in the figure, a composite patch (404) is applied to the reprocessing area (402) to reprocess the composite part (400), thereby effectively mitigating the previously present inconsistencies. In different embodiments, the composite patch (404) may take the form of liquid composite resin or prepreg tape or other composite materials.

[0079] In this example, the reprocessed area (402) comprises three sub-regions: a first sub-region (406), a second sub-region (408), and a third sub-region (410). Because the thicknesses of the sub-regions vary relative to each other, the composite patch (404) may require varying amounts of heating to maintain a uniform temperature difference across the entire composite patch (404). Regarding Figure 1 And the following about Figures 5 to 7 The described heating blanket system (100) can be used to heat the composite patch (404) by a temperature difference that varies within a predetermined temperature threshold.

[0080] Figure 5 A system for generating on-demand printed thermal blankets according to one or more embodiments is shown. Figure 5 The system shown can be used to... Figure 2 and Figure 3 The described method is used to manufacture Figure 1 The heated blanket system (100) shown. Therefore, Figure 5 The system shown can be used to generate materials for further processing. Figure 4 The assembly of the composite part (400) shown.

[0081] Figure 5 The system shown includes a computer (500). The computer (500) may be a laptop computer, desktop computer, tablet computer, mobile phone, or other computing device.

[0082] The computer (500) includes software that, when executed by a processor using data describing the reworked areas and the composite part being reworked, generates a thermal model (502). The thermal model (502) describes predicted differential heating in different sub-regions of the composite part to maintain temperature differences within acceptable thresholds throughout the composite patch. Thus, for example, referring to… Figure 4 The thermal model (502) can describe a first temperature to be applied to the first sub-region (406), a second temperature to be applied to the second sub-region (408), and a third temperature to be applied to the third sub-region (410), such that the composite patch (404) will maintain a constant temperature (within an acceptable temperature difference threshold) throughout the composite patch (404) during the curing process. An example of the thermal model (502) is shown in Figure 13 The middle part is shown as a thermal model (1300).

[0083] The computer (500) also includes software that, when executed by a processor using data describing the reworked areas, the composite part being reworked, and the thermal model (502), generates a blanket design (504). Therefore, the blanket design (504) is a data structure containing data stored in a non-transitory computer-readable storage medium. The blanket design (504) specifies the location, shape, and density of heating elements disposed in the various sub-regions of the thermal blanket system. Thus, the blanket design (504) can describe, for example... Figure 1 The heated blanket system (100) shown or Figure 6 The layout of a portion of the heated blanket system is shown. Regarding... Figure 14A and Figure 14B An example of a blanket design (504) is described.

[0084] The blanket design (504) can be provided to a 3D printer (506). The 3D printer (506) can print a resistance heating element onto the heating blanket system (508) using resistive ink. The 3D printer (506) can also print a 3D tube onto the heating blanket system (508) to create a fluid channel through which heating fluid can be pumped during the curing process. The heating element can also take other forms. In addition, as mentioned above, other types of printers or deposition apparatuses besides the 3D printer can be used.

[0085] The 3D printer (506) can also print other aspects of the heating blanket system (508). For example, the 3D printer (506) can print or build a substrate on which heating elements are printed. The 3D printer (506) can print or build dielectric or insulating laminate layers on one or both sides of the substrate. The 3D printer (506) can also print or apply other devices, such as, but not limited to, thermal sensors, thermocouples, control circuits, alarm devices, electrical systems, gas sensors, and other types of features, and can also punch holes in the heating blanket system (508).

[0086] In addition to the 3D printer (506), other devices may be used. For example, a machine may be used to cut a substrate from raw material before using the 3D printer (506). The raw material substrate may be fed to the 3D printer (506) so that heating elements can be printed on the substrate. The substrate with heating elements may then be provided to a laminator so that one or both sides of the substrate can be laminated. Additional machines may be used to add additional features or devices to the heating blanket system (508), or to peel off certain sub-regions of the heating blanket system (508) of previously established layers. Thus, one or more embodiments are contemplated in Figure 5 The system shown may contain more than just a 3D printer (506).

[0087] in any case, Figure 5 The system shown manufactures a heated blanket system (508). Then, for example, as... Figure 6 As shown, the heating blanket system (508) can be used to apply heat to a composite patch placed in the reprocessing area.

[0088] Figure 6 Specific examples and methods of using an on-demand printed thermal blanket system according to one or more embodiments are shown. Figure 7 An illustration is provided according to one or more embodiments. Figure 6 The application of the on-demand printed thermal blanket system is shown as a specific example. Figure 6 and Figure 7 It should be viewed as a whole. Therefore, Figure 6 and Figure 7 Share common reference figures.

[0089] Figure 6 and Figure 7 The example shown is Figure 1 The heated blanket system 100 shown and Figure 2 and Figure 3 A variation of the method shown. Figure 6 and Figure 7 The example shown can be used as about Figure 5 The manufactured heating blanket system (508) is applied to Figure 4 The composite part shown is (400).

[0090] In the example shown, the composite structure (600) is part of an aircraft fuselage or wing. Thus, for example, the composite structure (600) includes a skin (602) formed of a composite material supported by multiple reinforcing elements, such as reinforcing elements (604) and (606)). The reinforcing elements act as heat sinks; that is, relative to the portion of the skin (602) under which no reinforcing elements are present, the reinforcing elements absorb more heat applied to the skin (602).

[0091] Inconsistencies (700) exist in the skin (602) of the composite structure (600). Initially, the technicians' task was to mitigate these inconsistencies (700).

[0092] Initially, the technician prepares the composite structure (600) for reprocessing by defining a reprocessing area (702). The reprocessing area (702) is indicated by a marking line. The technician removes the composite material from the skin (602) in the reprocessing area (702) and prepares a prepreg patch (704) having the same shape and size as the reprocessing area (702). The prepreg patch (704) is a composite material or composite material layer prepreg-impregnated with liquid resin. The technician applies the prepreg patch (704) to the reprocessing area (reprocessing area (702)).

[0093] Technicians measured that the prepreg patch (704) is thicker between the first reinforcing element (604) and the second reinforcing element (606) relative to the outside of the prepreg patch (704). Technicians also noted that the first reinforcing element (604) and the second reinforcing element (606) will be used as heat sinks during the curing process of the prepreg patch (704).

[0094] Therefore, the technician inputs data about the composite structure (600), the reworked area (702), and the prepreg patch (704) into the thermal modeler software on the computer to generate a thermal model (1300). The thermal modeler software can query the existing model-based definition of the structure based on the reworked location coordinates and part number. The thermal model (1300) takes into account the thermodynamic properties of the skin (602), the first reinforcing element (604), the second reinforcing element (606), and the prepreg patch (704). The thermal model (1300) also takes into account the effect of different thicknesses of the prepreg patch (704) along its length. The thermal model (1300) indicates that a first specific amount of heat should be applied to the reprocessed area (702) in the region of the first reinforcing element (604) and the second reinforcing element (606), a second specific amount of heat should be applied to the center of the thickest prepreg patch (704), a third specific amount of heat should be applied to the edge of the prepreg patch (704), and a fourth specific amount of heat should be applied to other locations of the prepreg patch (704). The thermal model (1300) indicates a heating pattern that, if applied to the prepreg patch (704), will produce a constant temperature at least within an acceptable temperature threshold throughout the prepreg patch (704) during curing.

[0095] The thermal model (1300) is provided as input to a design software module on a computer to generate a print design. The design software module outputs a design of a pattern for the resistance heating element (608) on the heating blanket system (610). The design also includes a series of perforations, such as perforations (612), through which gases generated during curing can escape from the prepreg patch (704).

[0096] The printed design illustrates four distinct sub-regions of a heating blanket system (610) with resistance heating elements (608) of varying densities. For example, a first sub-region (614) is positioned around the edge of the heating blanket system (610). The density of the resistance heating elements (608) in the first sub-region (614) is higher than that in the second sub-region (616), which lies precisely inside the edge where the skin (602) will be present, but where the first reinforcing element (604) and the second reinforcing element (606) will not be. However, the highest density of the resistance heating elements (608) is placed in the third sub-region (618) and the fourth sub-region (620), as these sub-regions correspond to the locations where the first reinforcing element (604) and the second reinforcing element (606) (which serve as heat sinks) will be located. The printed design also illustrates a junction (622) on which a power source (624) can be placed.

[0097] Then, the technicians provide the printing design to the 3D printing machine, such as... Figure 5 The 3D printer (506) is shown. The 3D printer can optionally print a substrate, or can provide a substrate for the heating blanket system (610). The 3D printer prints a resistance heating element (608) onto the substrate. The 3D printer can also print a laminate onto the resistance heating element (608). The result is a customized, on-demand printed heating blanket system that can be used for specific reprocessing projects that have been requested by technicians.

[0098] The technician then places the heating blanket system (610) on the reworked area (702) of the prepreg patch (704). As shown by the dashed lines (such as dashed line (706)), the different sub-regions of the heating blanket system (610) identified above cover specific areas of the reworked area (702) that will have different thermodynamic properties. For example, the third sub-region (618) and the fourth sub-region (620) cover the radiator caused by the first reinforcing element (604) and the second reinforcing element (606), respectively. The first sub-region (614) covers the edge of the reworked area (702). The second sub-region (616) covers the area away from the edge of the reworked area (702) and also away from the covering skin (602) of the first reinforcing element (604) and the second reinforcing element (606). In other words, the corresponding density of the resistance heating element (608) is specifically matched to the thermodynamic curve (thermal model (1300)) of the rework project that the technician has been asked to perform.

[0099] The technician turns on the power supply (624), which provides a constant current source to the resistance heating element (608). Due to the varying density of the resistance heating element (608) in different sub-regions of the heating blanket system (610), the heating blanket system (610) generates different amounts of heat to different areas of the prepreg patch (704).

[0100] Therefore, even if the heat sink and thermodynamic edge effects may have caused temperature variations along the entire length of the prepreg patch (704), the prepreg patch (704) remains at a constant temperature along its entire length within the specified engineering tolerances.

[0101] The curing process can be monitored, for example, by monitoring the temperature of different sub-regions of the prepreg patch (704) in the reprocessing area (702). In this case, the temperature remains constant within ±10 degrees Fahrenheit throughout the prepreg patch (704) over the four hours used to cure it. When the curing process is complete, the heating blanket system (610) is removed from the reprocessing area (702), the reprocessing process is complete, and the inconsistencies (700) have been mitigated.

[0102] In summary, the composite structure (600) undergoing reprocessing has a skin with integrated I-beam reinforcement elements. The burn-out reprocessing on the skin surface extends across the flanges of the two I-beam reinforcements. Querying the part model at this location on the structure and performing thermal analysis indicates that higher heat density will be applied to the reprocessing location shared by the longitudinal beam flanges. The "skin-only" areas between the reinforcements require lower heat density. The edges of the thermal blanket system require higher heat density to compensate for heat loss at the edges of the thermal blanket system.

[0103] Thermal Analysis Module (TAM) (generates) Figure 5 The thermal model (502) or Figure 13 The thermal model (1300) software calculates the heat density used to achieve uniform isothermal conditions for the reprocessed part. The heat density data is output to the Blanket Design Module (BDM) (which generates...). Figure 5 Blanket design in (504) or about Figure 14A and Figure 14B The described thermal density diagram (1400) and the corresponding blanket design software. BDM determines the watt density to achieve uniform temperature during the curing process.

[0104] The desired wattage density is achieved by varying the spacing of the resistance heating wires. Areas requiring higher heat density have the heating elements placed more closely together, while areas requiring less heat have them spaced further apart. This spacing is defined by the BDM (Body Design Model).

[0105] The circuitry is printed or deposited on a thin, flexible film, such as paper, KAPTON®, or fiberglass. The circuit array is then laminated to encapsulate and insulate the electrical traces. The circuit traces are terminated using standard power input cables.

[0106] The heating blanket system is connected to a controller and is used to cure the composite material. The heat output density of the heating blanket system is perfectly matched to the heat density requirements of the composite structure (600) being reprocessed. In short, the heating blanket system (610) is custom-designed for the specific application of heat uniformity during curing, but is manufactured on-site and can therefore be considered an "on-demand" heating blanket system.

[0107] We should consider this together. Figures 8 to 14B . Figures 8 to 14B A concrete example of generating a design for a heating element to be printed on a heated blanket system is shown, wherein a heating model is used to generate the design. Therefore, Figures 8 to 14B A concrete example is shown of how a custom-designed heating blanket system can be created and manufactured based on a heating model, where the system is intended for a specific reprocessing project to be performed on a particular aircraft panel. Therefore, Figures 8 to 14B A shared reference number can refer to a common object that has a common description.

[0108] Figures 8 to 14B The examples shown are not intended to limit the other examples or claimed inventions described herein, as other examples are also possible. Any values, shapes, designs, etc., may vary depending on the specific project or embodiment.

[0109] First, shift your attention Figures 8 to 10 . Figure 8 An aircraft panel (800) with a reprocessed area (802) including inconsistencies (804) is shown according to one or more embodiments. Figure 8 The outer molding line can be characterized as an aircraft panel (800). The aircraft panel (800) is formed of a composite material. Inconsistencies (804) will be reprocessed using a process involving curing composite patches, composite liquids or gels, prepreg patches, or other composite materials to which heat is applied to cure the reprocessed area.

[0110] Figure 9 An illustration is provided according to one or more embodiments. Figure 8 An alternative illustration of the aircraft panel (800). Specifically, Figure 9 It shows Figure 8 The opposite sides of the aircraft panel (800) shown, and therefore can be characterized as the internal molding lines of the aircraft panel (800).

[0111] The internal molding lines show multiple reinforcements, such as reinforcement (900) and reinforcement (904), extending along the length of the aircraft panel (800). In this example, the reinforcements are hollow, but not necessarily. In this particular example, the reinforcements may be characterized as “hat-shaped” reinforcements or as “ω-reinforcements.” In different embodiments, the reinforcements may have different shapes.

[0112] The internal molding line also shows multiple frame elements, including frame element (906) and frame element (908). Each frame element can be a solid material, including aluminum, composite materials, etc., for circumferentially reinforcing the aircraft panel (800) along the aircraft panel (800). However, the frame elements can also be hollow and have various different shapes and can be made of various different materials.

[0113] Figure 10 An illustration is provided according to one or more embodiments. Figure 8A cross-section of the aircraft panel (800). The aircraft panel (800) is shown as a skin. A frame element (in this case, frame element (906)) is shown attached to the aircraft panel (800) at the skin-to-frame interface (1000). A reinforcement (900) also attached to the aircraft panel (800) along two flanges (including flanges (1002) and (1004) of the reinforcement (900) is shown passing beneath the frame element (906). The reinforcement (900) may or may not be attached to the frame element (906). A cavity (1006) is provided inside the reinforcement (900) and may extend along the length of the reinforcement (900).

[0114] A heated blanket system (1008) is shown for reference. The heated blanket system (1008) is as follows: Figure 14A and Figure 14B The described design is for a custom-designed heated blanket system.

[0115] Figure 11 The following are examples illustrating the use of one or more embodiments for generating Figure 8 The heating model shown is part of the heating simulation process of the panel. Figure 12 The following are examples illustrating the use of one or more embodiments for generating Figure 8 The heating model of the panel shown is part of the process. Figure 11 Another part of the heating simulation.

[0116] Thermal analysis was performed on the simulation panel (1100), which corresponds to Figures 8 to 10 The aircraft panel (800) is shown. The simulation panel (1100) also has simulation reinforcements, such as simulation reinforcement (1102), which corresponds to Figures 8 to 10 The reinforcing member shown is also included in the model. Figures 8 to 10 The simulated frame element shown is a frame element such as simulated frame element (1104).

[0117] The specifications or thickness of the aircraft panel (800) are constant. However, the heat load varies considerably due to the following reasons. The enclosed cap-shaped longitudinal beam cavity (1006) creates an insulating air gap within the longitudinal beam cavity (1006) to prevent convective heat loss. This area will trap heat and create localized hot spots on the common outer skin of the longitudinal beam cavity (1006). Meanwhile, the cap-shaped longitudinal beam flanges covering the aircraft panel (800) (such as flanges (1002) and (1004)) locally increase the skin thickness, thereby creating a radiator directly adjacent to the insulating air gap created by the longitudinal beam cavity (1006). A further complicating issue is the frame attachment point between the cap-shaped longitudinal beams, characterized by the skin-to-frame interface (1000). The frame attachment shear band (i.e., the skin-to-frame interface (1000)) spans the gap between each cap-shaped longitudinal beam at each frame location. In this specific embodiment, each frame attachment location is a localized radiator of approximately 2 × 6 inches.

[0118] return Figure 11 The first simulation region is located at the center of the longitudinal beam cavity (1006) in the longitudinal direction. The first simulation region corresponds to the reprocessing region (802). The frame element (906) spans the simulation region near the right edge.

[0119] return Figure 12 The second simulation region illustrates the convective heat loss that occurs when simulated heating is applied to the first simulation region. The first and second simulation regions together form the heating simulation.

[0120] Heating simulations can take other conditions into account. For example, heating simulations can also take into account the insulation properties of the vacuum-packed materials used in the composite curing process.

[0121] During the reprocessing simulation, the first simulated region is virtually heated using thermal energy equivalent to a 5-watt resistance heating blanket system per square inch. The duty cycle of the simulated heat source is modulated to achieve a maximum temperature of 360 degrees Fahrenheit anywhere within the first simulated region. This power level is maintained until all temperature variations within the first simulated region are approximately zero.

[0122] Figure 13 An illustration is provided according to one or more embodiments. Figure 8 The heated model of the aircraft panel (800) shown. Figure 13 It shows about Figure 11 and Figure 12 The results of the heating simulation performed, and therefore Figure 13 An example of the thermal model (1300) is shown.

[0123] The resulting simulated temperatures were depicted in contour spans within the reprocessing area (1302), where each span indicates a temperature difference of approximately 20 degrees Fahrenheit. A temperature scale (1304) is shown for reference. As illustrated in the legend provided by the temperature scale (1304), the hash patterns within the spans show different temperature ranges, from the hottest area (approximately 360°F to 340°F) to the coldest area (approximately room temperature (70°F)).

[0124] exist Figure 13 The line (1306) extending from left to right follows the cap-shaped longitudinal beam cavity (1006). Figure 13 The line (1308) extending from top to bottom follows the fuselage frame. The central part of the common rework area (1302) of the longitudinal beam cavity (1006) is the hottest area. However, the strong heat dissipation effect of the skin-to-frame interface (1000) (again indicated by the line (1308)) is clearly visible in the area (1310) to the right of the rework area (1302).

[0125] Data from the initial tests are used to define discrete temperature bands or regions within the reworked area (1302). The dimensional coordinates of the hot regions are defined by a Thermal Analysis Module (TAM) on the part model. Iterative thermal simulations can then be performed by the TAM. The simulated heat output (watts per square inch) increases or decreases independently within each region. This cycle is repeated until the desired thermal uniformity is achieved within the reworked area (1302).

[0126] The final output of TAM is a structure-based, model-defined thermal analysis and a thermal density map of the thermal blanket system at inconsistent locations on the aircraft panel (800). Below... Figure 14A and Figure 14B An example of a heat density diagram for a heated blanket system is shown.

[0127] Figure 14A and Figure 14B A diagram illustrating a source according to one or more embodiments is provided. Figure 13 Different illustrations of the heat density map of the heating blanket system generated by the heating model in the diagram are shown. The heat density map (1400) of the heating blanket system serves as a guide for determining the density of heating elements to be placed in each corresponding region of the heat density map (1400). Specifically, the spacing of the heating elements can be inferred from the specific wattage of heating to be applied to a particular region. Therefore, Figure 14A and Figure 14B Effectively demonstrates the use Figure 13 The heating model is generated for the design of heating elements to be printed on the heat blanket system to be applied to the aircraft panel (800).

[0128] The heat density map (1400) includes different regions, such as region A (1402), region B (1404), region C (1406), and region D (1408). Each region is represented by a different hash pattern. Each region receives a predetermined number of watts of heat energy. The heating blanket system will apply 8 watts of heat energy in region A (1402). The heating blanket system will apply 6 watts of heat energy in region B (1404). The heating blanket system will apply 4 watts of heat energy in region C (1406). The heating blanket system will apply 3 watts of heat energy in region D (1408). As a whole, when the heat energy of the above patterns is applied to the reprocessing region (802) by the customized heating blanket system, the final temperature achieved in the reprocessing region (802) is approximately uniform (i.e., within a predetermined temperature threshold). Therefore, despite the fact that there are differences in heat absorption rates in the reprocessing area (802), the prepreg patch or other composite material used for reprocessing inconsistencies (804) maintains a uniform temperature throughout the curing process.

[0129] Note that once the size, shape, and heat density of each region are defined, the heating model data can be output to the circuit design module to design the circuit traces for the printed heating blanket system, ensuring that the traces generate a specified number of watts of heat energy when powered on. At this stage, the heat density regions can be edited based on user input to improve manufacturing. If the changes are deemed significant, the resulting production design can be rerun through the TAM module to ensure that the changes do not unintentionally affect the performance of the heating blanket system.

[0130] Therefore, one or more of the above embodiments provide a print-on-demand (POD) heating blanket system (printable via direct-write circuitry, inkjet printers, or 3D printers). When a part is to be reworked, its model-based definition can be queried to understand the exact composition of the part at inconsistencies and any attached substructures or systems. Understanding the composition and substructures of the part allows for the performance of a finite element analysis (FEA) to determine the thermal energy required to heat the region of interest (ROI) to a uniform temperature. The heating requirement can be modeled like any other property of the ROI, much like stress or strain. Given this heat flux and heat density data, even if the part's heat requirement varies significantly across the ROI, custom heating circuitry can be designed and printed onto the heating blanket system to uniformly heat the ROI. For example, if the ROI has localized areas with a reinforcing layer, the custom circuitry will have corresponding areas where the resistance wires are spaced very closely together to achieve a higher heat density in that specific area. Meanwhile, other areas with thinner skin will have the resistance wires spaced further apart to avoid overheating in those locations.

[0131] The following is a summary of an exemplary handling process for an aircraft.

[0132] 1) Define inconsistent positions and sizes / depths in the aircraft coordinate system.

[0133] 2) Input the inconsistency definition data into the Thermal Analysis Module (TAM).

[0134] 3) TAM query parts are based on the Model Definition (MBD) to determine the composition of parts in the area of ​​interest.

[0135] 4) TAM calculations are used to determine the amount of heat energy / density to be applied to the ROI region in order to achieve isothermal maintenance of the desired reprocessing curing temperature.

[0136] 5) TAM outputs thermal density data to the Blanket Design Module (BDM).

[0137] 6) BDM is based on specific component MBD design to create circuits for heating blanket systems with variable wire spacing to achieve uniform heating of the ROI.

[0138] 7) BDM determines the optimal location of the temperature sensor and incorporates it into the design.

[0139] 8) BDM outputs the sensor design to the printing press.

[0140] 9) The printing press prints circuits and sensors onto a heat-resistant / flexible printing medium to form a thermal blanket system.

[0141] 10) Perform electrical termination on the heated blanket system.

[0142] 11) The circuit passes through a laminator to encapsulate and insulate the circuit for use.

[0143] 12) Power cables and sensor cables are added to the heating blanket system.

[0144] 13) Place the heated blanket system on the ROI according to the location instructions.

[0145] 14) Perform the curing process.

[0146] 15) The heated blanket system is installed, recycled, or stored.

[0147] Figure 15 A method for manufacturing and maintaining an aircraft according to one or more embodiments is shown. Figure 16 An aircraft according to one or more embodiments is shown. These should be considered together. Figure 15 and Figure 16 .about Figures 1 to 9 The described methods and systems can be found in Figure 15 Used in the context of the aircraft manufacturing and maintenance methods (1500) shown. Similarly, regarding... Figures 1 to 9 The described methods and systems can be used for further processing of... Figure 16The various parts of the aircraft (1600) shown.

[0148] Go to Figure 15 During pre-production, the exemplary aircraft manufacturing and maintenance method (1500) may include Figure 16 Specifications and design of the aircraft (1600) (1502) and material procurement for the aircraft (1600) (1504). During production, [the process involves...] Figure 16 The manufacturing of components and sub-components of the aircraft (1600) (1506) and system integration (1508). Subsequently, Figure 16 The aircraft (1600) can be certified and delivered (1510) for use (1512). When used by the customer, Figure 16 The aircraft (1600) in the middle were assigned to routine maintenance and upkeep (1514), which could include modifications, reconfigurations, refurbishments and other maintenance or upkeep.

[0149] Each process of the aircraft manufacturing and maintenance method (1500) may be performed or implemented by a systems integrator, a third party, and / or an operator. In these examples, the operator may be the customer. For the purposes of this specification, a systems integrator may include, but is not limited to, any number of aircraft manufacturers and major systems subcontractors; a third party may include, but is not limited to, any number of suppliers, subcontractors, and vendors; and an operator may be an airline, leasing company, military entity, service organization, etc.

[0150] Now for reference Figure 16 An illustration of an aircraft (1600) is shown, in which advantageous embodiments can be implemented. In this example, by... Figure 15 The aircraft (1600) is produced using the aircraft manufacturing and maintenance methods (1500). The aircraft (1600) may include a fuselage (1602) having systems (1604) and an interior (1606). Examples of systems (1604) include one or more of a propulsion system (1608), an electrical system (1610), a hydraulic system (1612), and an environmental system (1614). Any number of other systems may be included.

[0151] Although an aerospace example has been shown, different advantageous embodiments can be applied to other industries, such as the automotive industry. Thus, for example, in one or more embodiments, the aircraft (1600) can be replaced by a car or other means of transportation or object.

[0152] It is possible Figure 15 The equipment and methods embodied herein may be used during any one or more stages of the aircraft manufacturing and maintenance methods (1500). For example, similar to those in... Figure 15The components or sub-components produced when the aircraft (1600) was put into service (1512) were manufactured or produced in the manner of making or manufacturing them. Figure 15 Components or sub-components produced in the manufacturing of components and sub-components (1506).

[0153] Additionally, for example, by substantially accelerating the assembly of the aircraft (1600) or reducing the cost of the aircraft (1600), it is possible to improve production processes (such as...). Figure 15 During the manufacturing of components and subcomponents (1506) and system integration (1508), one or more of the device embodiments, method embodiments, and combinations thereof are utilized. Similarly, when in Figure 15 When the aircraft (1600) is put into service (1512) or during maintenance and upkeep (1514), one or more of the equipment embodiments, method embodiments and combinations thereof may be used.

[0154] For example, one or more advantageous embodiments may be applied during component and subcomponent manufacturing (1506) to rework inconsistencies that may be found in the composite structure. As yet another example, one or more advantageous embodiments may be implemented during maintenance and upkeep (1514) to remove or mitigate identifiable inconsistencies. Therefore, measures regarding... Figures 1 to 9 One or more embodiments are described to remove or mitigate identifiable inconsistencies.

[0155] Furthermore, this disclosure includes embodiments based on the following examples: Example 1. A method that includes: Receive a digital model of at least a portion of a composite structure with inconsistencies, wherein the digital model includes a pre-calculated heating model specifying multiple regions of inconsistency, and for each region, applying different amounts of heating to the uncured composite material with inconsistencies. The design of multiple heating elements with varying densities across multiple regions is generated based on the digital model, wherein: The design is configured such that multiple heating elements in the first sub-zone of the heated blanket system generate first heat in a third zone of multiple zones. The design is further configured to allow multiple heating elements in the second sub-zone of the blanket system to generate a second heat in a fourth zone of multiple zones, and The first calorie is different from the second calorie; and According to the design, multiple heating elements are printed on the blanket to manufacture a heated blanket system.

[0156] Example 2. Based on the method of Example 1, it further includes: Inconsistency is reprocessed by applying uncured composite material to the inconsistency; After reprocessing, the heating blanket system is placed on the uncured composite material; and Uncured composite materials are cured by generating heat through multiple heating elements.

[0157] Example 3. The method according to Example 2, wherein the plurality of heating elements includes resistance heating elements, and wherein the method further includes: Connect the resistance heating element to a power source; and Electricity is applied to the resistance heating element.

[0158] Example 4. Based on the method of Example 1, further including: Multiple thermal sensors are printed on the heated blanket system to sense multiple temperatures in the third and fourth zones, wherein the heated blanket system further includes multiple thermal sensors.

[0159] Example 5. Based on the method of Example 4, further including: Inconsistency is reprocessed by applying uncured composite material to the inconsistency; After reprocessing, the heating blanket system is placed in an inconsistent manner; Uncured composite materials are cured by generating heat through multiple heating elements; and Multiple temperatures in the third and fourth regions are monitored using multiple thermal sensors.

[0160] Example 6. Based on the method of Example 5, further including: An alarm is generated if the first temperature in the third zone exceeds the second temperature in the fourth zone by a factor of 10.

[0161] Example 7. Based on the method of Example 6, further including: An alarm device is printed on the heated blanket system, which communicates with multiple thermal sensors.

[0162] Example 8. The method of Example 1, wherein printing is performed by using a 3D printer programmed with the design.

[0163] Example 9. A heated blanket system comprising: The blanket includes a first sub-region and a second sub-region; and Multiple heating elements are printed on the blanket, including: The first spacing between the first heating elements in the first sub-region varies relative to the second spacing between the second heating elements in the second sub-region. The first and second spacings vary depending on the design. The design is configured for a uniquely defined reprocessing region on a uniquely defined composite object, which includes a third region and a fourth region, the third region comprising a heat sink region and the fourth region comprising a non-heat sink region. The size and dimensions of the first sub-region are set to be placed on the third region, and The size and dimensions of the second sub-region are set to be placed on the fourth region.

[0164] Example 10. A heated blanket system according to Example 9, wherein the first spacing is smaller than the second spacing.

[0165] Example 11. The heated blanket system according to Example 9 further includes: The power supply is connected to multiple heating elements.

[0166] Example 12. A heated blanket system according to Example 11, wherein, Multiple heating elements include resistance heating elements, The power supply includes a single power source, and The power supply is configured to apply approximately constant current to multiple heating elements.

[0167] Example 13. A heated blanket system according to Example 9, wherein the blanket further includes a plurality of perforations provided through the blanket.

[0168] Example 14. The heated blanket system according to Example 9 further includes: Thermal sensors printed on a blanket.

[0169] Example 15. The heated blanket system according to Example 14 further includes: A wireless transmitter connected to a thermal sensor; and The control circuitry printed on the blanket is configured to modify the power delivered to multiple heating elements based on signals received by a wireless transmitter.

[0170] Example 16. According to the heated blanket system of Example 9, where: Blankets include paper or polyethylene terephthalate (PET), and Multiple heating elements include conductive ink or resistive ink.

[0171] Example 17. A heated blanket system according to Example 16, wherein the blanket further comprises: The first dielectric layer is disposed on the first side of the paper or PET, and The second dielectric layer is disposed on the second side of the paper or PET opposite to the first side.

[0172] Example 18. A method for reprocessing an aircraft comprising a composite material having regions including inconsistencies, the method comprising: Aircraft are manufactured for reprocessing by preparing composite materials in areas of inconsistency; A digital model of the inconsistency region is generated, wherein the digital model includes a heating model of multiple sub-regions specifying the inconsistency region, and for each sub-region, different amounts of heating are applied to the uncured composite material to which the inconsistency is applied. The design of multiple heating elements for varying densities across multiple sub-regions is generated based on the digital model; where: The design is configured to enable multiple heating elements to generate first heat in a first sub-region of multiple sub-regions; The design is further configured to allow multiple heating elements to generate second heat in a second sub-region of multiple sub-regions; and The first calorie is different from the second calorie; According to the design, multiple heating elements are printed onto the blanket using a 3D printer to manufacture the heated blanket system; Apply uncured composite patches to inconsistent areas; Apply the heating blanket system to the uncured composite patch; and Uncured composite patches are cured by applying differential heating to them using a heating blanket system.

[0173] Example 19. Based on the method of Example 18, further including: The first and second thermal sensors are printed on the blanket as part of the heating blanket manufacturing system. In this system, a first thermal sensor is printed on the heating blanket system to measure a first temperature in a first sub-region, and The second thermal sensor is printed on the heating blanket system to measure the second temperature in the second sub-region.

[0174] Example 20. Based on the method of Example 19, further including: During curing, the first temperature is measured using a first thermal sensor; During curing, a second temperature is measured using a second thermal sensor; and In response to the difference between the first temperature and the second temperature exceeding a threshold temperature difference, actions are taken to mitigate the difference between the first temperature and the second temperature.

[0175] Although the invention has been described with respect to a limited number of embodiments, those skilled in the art who benefit from this disclosure will understand that other embodiments can be devised without departing from the scope of the invention disclosed herein. Therefore, the scope of the invention should be limited only by the appended claims.

Claims

1. A heated blanket system, comprising: The blanket includes a first sub-region and a second sub-region; as well as Multiple heating elements are printed on the blanket; A power supply is connected to the plurality of heating elements, wherein: The first spacing between the first heating elements in the first sub-region varies relative to the second spacing between the second heating elements in the second sub-region. The first spacing and the second spacing vary according to the design. The design is configured for a uniquely defined reprocessing region on a uniquely defined composite material object, the composite material object including a third region and a fourth region, the third region including a heat sink region and the fourth region including a non-heat sink region. The size and dimensions of the first sub-region are set to be placed on the third region, and The size and dimensions of the second sub-region are set to be placed on the fourth region.

2. The heated blanket system according to claim 1, wherein, The plurality of heating elements include resistance heating elements. The power supply includes a single power source, and The power supply is configured to apply a constant current to the plurality of heating elements.

3. The heated blanket system according to claim 1, further comprising: A thermal sensor printed on the blanket.

4. The heated blanket system according to claim 3, further comprising: A wireless transmitter connected to the thermal sensor; as well as Control circuitry printed on the blanket is configured to modify the power delivered to the plurality of heating elements based on signals received by the wireless transmitter.

5. The heated blanket system according to claim 1, wherein: The blanket comprises paper or polyethylene terephthalate, and The plurality of heating elements include conductive ink or resistive ink.

6. The heated blanket system according to claim 5, wherein, The blanket further includes: A first dielectric layer is disposed on the first side of the paper or polyethylene terephthalate, and A second dielectric layer is disposed on the second side of the paper or polyethylene terephthalate opposite to the first side.

7. A method for reprocessing an aircraft, the aircraft comprising a composite material having regions including inconsistencies, the method comprising: The aircraft is manufactured by preparing the composite material in the areas of inconsistency for reprocessing; A digital model of the inconsistency region is generated, wherein the digital model includes a heating model of multiple sub-regions specifying the inconsistency region, and different amounts of heating are applied to the uncured composite material applied to the inconsistency region for the multiple sub-regions; The design of multiple heating elements for varying densities across the multiple sub-regions is generated based on the digital model; wherein: The design is configured such that the plurality of heating elements generate first heat in a first sub-region of the plurality of sub-regions; The design is further configured to cause the plurality of heating elements to generate second heat in a second sub-region of the plurality of sub-regions; and The first calorie is different from the second calorie; According to the design, the plurality of heating elements are printed onto the blanket using a 3D printer to manufacture a heated blanket system; Apply the uncured composite patch to the inconsistent area; The heating blanket system is applied to the uncured composite patch; and The uncured composite patch is cured by applying differential heating to the uncured composite patch using the heating blanket system.

8. The method of claim 7, further comprising: The first and second thermal sensors are printed on the blanket as part of the manufacture of the heated blanket system. The first thermal sensor is printed on the heating blanket system to measure the first temperature in the first sub-region, and The second thermal sensor is printed on the heating blanket system to measure the second temperature in the second sub-region.

9. The method of claim 8, further comprising: The first temperature is measured using the first thermal sensor during the curing process; The second temperature is measured using the second thermal sensor during the curing process; and In response to the difference between the first temperature and the second temperature exceeding a threshold temperature difference, actions are taken to mitigate the difference between the first temperature and the second temperature.

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