Patent Application
20240342842
Aspects of the present disclosure relate to repair components for composite structures. More specifically, this disclosure relates to a system of prefabricated repair components that provide for quick and efficient repairs to damaged portions of composite structures.
Fiber-reinforced plastics, such as epoxy-based carbon fiber-reinforced plastic (CFRP) composites, have high strength-to-weight ratios and increased durability. These advantages have led to the wide use of composite structures formed from CFRPs in the aerospace industry (e.g., as structural/frame components of aircraft), as well in various other industries.
While fiber-reinforced plastics have many advantages, the repair of composite structures formed from fiber-reinforced plastics can be time-consuming and, therefore, expensive. For example, once a CFRP material is cured in a certain size or shape, the part is geometrically locked to that size and shape. Challenges arise when a part formed with CFRP material is damaged and requires repair, particularly when the part has a curved or complex geometry. This often leads to the need for custom repair parts that are fabricated for a specific damaged component.
Existing processes for repairing a damaged CFRP or composite part include creating a tooling surface and fabricating an overlay part to match the part geometry. These processes can be time consuming and result in added delay to getting the composite structure back into useful service. Providing prefabricated repair components which are usable across many different structures/members in a composite structure system remains a challenge.
One general aspect includes a repair component for a composite member. The repair component includes a first flange section, a second flange section, and a repair section between the first flange section and the second flange section. The repair section may include an internal cross-sectional profile defined on a repair surface of repair section, where the repair section is positioned over at least a damaged section of the composite member, where the repair surface faces an external surface of the composite member, where the composite member may include an external cross-sectional profile defined on the external surface, and where the internal cross-sectional profile matches the external cross-sectional profile within a given tolerance.
Implementations may include one or more of the following features. The repair component where the external cross-sectional profile defined on the external surface of the composite member may include a hat-stiffened structural profile.
In one aspect, in combination with any example repair component above or below, the composite member may include a stringer component in an aircraft.
In one aspect, in combination with any example repair component above or below, the repair component may include a first surface on the first flange section, the second flange section, and the repair section, where the first flange section may include a second surface opposite the first surface, where the second flange section may include a third surface opposite the first surface, and where the repair component further may include a plurality of bolt holes, where each bolt hole of the plurality of bolt holes is formed through the repair component from the first surface to one of the repair surface, the first surface, and the second surface. The repair component is attached to the composite member via a plurality of fastened bolts, where each fastened bolt of the plurality of fastened bolts is positioned in a respective bolt hole of the plurality of bolt holes.
In one aspect, in combination with any example repair component above or below, the repair component may include one or more shims positioned between the repair component and the external surface of the composite member.
In one aspect, in combination with any example repair component above or below, the repair component may include a composite material.
In one aspect, in combination with any example repair component above or below, the repair component may include a fabrication length, where the repair component is cut down to a selectable length shorter than the fabrication length, prior to attachment to the composite member.
One general aspect includes a repair system for a composite structure. The repair system includes a total set of repair components, including a plurality of repair component subsets, where each repair component in respective repair component subset may include features for repairing a subset of composite structures in the composite structure system. Each repair component subset of the plurality of repair component subsets may include: at least one repair components may include sizing dimensions suitable to repair the subset of composite structures. Each repair component of the plurality of repair components may include: a first flange section, a second flange section, and a repair section between the first flange section and the second flange section. The repair component may include an internal cross-sectional profile defined on a repair surface of repair section, where the repair section is positioned over at least a damaged section of a composite member of the subset of composite members, where the repair surface faces an external surface of the composite member, where the composite member may include an external cross-sectional profile defined on the external surface, and where the internal cross-sectional profile matches the external cross-sectional profile within a given tolerance.
In one aspect, in combination with any example repair system above or below, the external cross-sectional profile may include a hat-stiffened structural profile.
In one aspect, in combination with any example repair system above or below, the composite structure system may include an aircraft, where the subset of composite structures may include a plurality of stringer components in the aircraft, and where the composite member may include a stringer in the aircraft.
In one aspect, in combination with any example repair system above or below, each repair component may include a first surface on the first flange section, the second flange section, and the repair section, where the first flange section may include a second surface opposite the first surface, where the second flange section may include a third surface opposite the first surface, and where each repair component further may include a plurality of bolt holes, where each bolt hole of the plurality of bolt holes is formed through the respective repair component from the first surface to one of the repair surface, the first surface, and the second surface. Each repair component is attached to the composite member via a plurality of fastened bolts, where each fastened bolt of the plurality of fastened bolts is positioned in a respective bolt hole of the plurality of bolt holes.
In one aspect, in combination with any example repair system above or below, the repair system may include one or more shims positioned between a respective repair component of the plurality of repair components and the external surface of the damaged section of the composite member.
In one aspect, in combination with any example repair system above or below, each repair component may include a composite material.
In one aspect, in combination with any example repair system above or below, each repair component may include a fabrication length, where a respective repair component is cut down to a selectable length shorter than the fabrication length, prior to attachment to the composite member.
One general aspect includes a method for repairing a composite member. The method includes selecting a repair component for a damaged section of a composite member from a repair component system based on an external cross-sectional profile of the composite member. The method also includes positioning the repair component over the damaged section such that a first flange section of the repair component is positioned on a first side of the composite member, a second flange section of the repair component is positioned over a second side of the composite member, and a repair section of the composite member between the first flange section and the section flange section is positioned over at least the damaged section of the composite member, and attaching the positioned repair component to the composite member.
In one aspect, in combination with any example method above or below, the repair section may include an internal cross-sectional profile defined on a repair surface of repair section, where the repair surface faces an external surface of the composite member, where the composite member may include an external hat-stiffened structural profile defined on the external surface, and where the internal cross-sectional profile matches the external hat-stiffened structural profile within a given tolerance.
In one aspect, in combination with any example method above or below, the composite member may include a stringer component in an aircraft.
In one aspect, in combination with any example method above or below, the repair component may include a first surface on the first flange section, the second flange section, and the repair section, where the first flange section may include a second surface opposite the first surface, where the second flange section may include a third surface opposite the first surface, and where the repair component further may include a plurality of bolt holes, where each bolt hole of the plurality of bolt holes is formed through the repair component from the first surface to one of a repair surface, the first surface, and the second surface. Attaching the positioned repair component to the composite member may include: positioning a plurality of bolts through the plurality of bolt holes such that the bolts pass through the repair component and the composite member, and fastening the plurality of bolts to secure the repair component to the composite member.
In one aspect, in combination with any example method above or below, positioning the repair component further may include: positioning one or more shims between the repair component and the external surface of the composite member to provide additional structural support.
In one aspect, in combination with any example method above or below, the method may include: determining a selectable length for the repair section based on a lateral length of the damaged section of the composite member, and cutting the selected repair component from a fabrication length to the selectable length.
So that the manner in which the above recited features can be understood in detail, a more particular description, briefly summarized above, may be had by reference to example aspects, some of which are illustrated in the appended drawings.
As described above, carbon fiber-reinforced plastic (CFRP) composites (herein composite(s)) are an increasingly important material used in a wide variety of industries including aerospace, automobile, marine, and other applications. These composite materials provide many advantages due to their light weight and relatively high strength and durability. However, repairing damaged composite structures can be difficult and expensive.
In some examples, repairing a damaged metallic member is often achieved using a preformed generic or near-generic metallic repair piece and then altering the metallic repair piece to fit the damaged section of the metallic member (e.g., through hammering, welding, or other metal-working processes). In contrast, composite materials have low malleability once cured and generally cannot be altered during a repair process. Thus, repairing a damaged composite structure typically requires a custom composite repair component to be fabricated that will fit the damaged section of the composite structure.
Additionally, composite structure systems often have a large variety of composite members with varying shapes, thicknesses, etc. For example, an aircraft utilizing composite structures may include many composite members where each composite member also has a varying structure at different points on the composite member (e.g., a curved member, etc.). This results in thousands of locations with unique geometries or shapes on the individual composite members in a composite system. Providing prefabricated repair components for each of the thousands of unique locations presents an inventory and logistical challenge for operators and manufacturers. For example, an aircraft manufacturer or an airline operator would need to fabricate and store an inventory of thousands of unique repair components in order to provide quick repairs to the composite members.
The repair systems, repair components, and methods described herein provide for repairing composite structure systems using a set number of prefabricated repair components which are fabricated to repair multiple composite members in a composite structure system.
The aircraft 100 includes an airframe 110 and a propulsion system 115. The airframe 110 includes a pair of wings 125 extending outwardly from a fuselage 120. The airframe 110 also includes a tail section having a horizontal stabilizer 134, a vertical stabilizer 132 and/or other control surfaces normally associated with an aircraft. Each part of the airframe 110 may include skin members 140 which may be internally supported by structural components as shown in in more detail in the depiction of section 150 of the airframe 110 in
In order to provide additional structural support, the airframe 110 includes stringer components (herein stringers) positioned between the various frame components. The stringers include stringers 220-1-220-2, 225-1-225-2, 230-1-230-2, 235-1-235-2, 240-1-240-4, 250-1-250-3, 255-1, 260-1-260-2, and 265-1-265-2. In some examples, due to the varying shape and structure of the airframe 110, the stringers have varying dimensions and shapes. These varying dimensions include varying ply/book numbers (thickness), lengths, internal cross-sections, curvature, etc. as described in more detail herein. However, the various stringers may include similar dimensions such that the stringers may be grouped into subsets of composite members. For example, the stringers 220-1 and 220-2 are in a subset 220. Stringers 225-1 and 225-2 are part of subset 225, stringers 235-1 and 235-2 are in subset 235, stringers 240-1-240-4 are in a subset 240, stringers 250-1-250-3 are in a subset 250, stringers 260-1 and 260-2 are in a subset 260, and stringers 265-1 and 265-2 are in a subset 265.
In some examples, the stingers in a same subset, such as the stringer 220-1 and the stringer 220-2 may have different shapes or other dimensions, but are the outer shapes are similar enough to utilize a same repair component as described in more detail herein. Varying shapes and dimensions are shown in more detail in relation to
For example,
For example,
In some examples, the repair component 400 also includes a plurality of bolt holes for attaching the repair component to a composite member. For example, the repair component 400 includes a first surface 430 on the first flange section 420, the second flange section 425, and the repair section 405. The first flange section 420 includes a second surface 422 opposite the first surface 430, the second flange section 425 includes a third surface 427 opposite the first surface 430. Bolt holes 440 are formed through the repair component 400 from the first surface 430 to the surfaces of the respective sections, including to one of the repair surface 415, the second surface 422, and the third surface 427. In some examples, the bolt holes 440 may be formed during the fabrication process creating the repair component 400 or may be formed during a repair of a damaged section of a composite member. In some examples, the repair component is attached to the composite member via a plurality of fastened bolts, where each fastened bolt of the plurality of fastened bolts is positioned in a respective bolt hole of the bolt holes 440.
In some examples, the repair component includes a fabrication length 450 which may be a standard length (e.g., 76 inches, etc.), The repair component 400 is cut down to a selectable length shorter than the fabrication length 450, prior to attachment to the composite member as described in more detail in relation to
For example, the subset 510 may be used to repair the subset 220 and subset 265 described in relation to
In some examples, the components in a subset of repair components may not have a precise geometrical match to a subset of composite members. For example, the repair component 511 may be used to match the geometries of the stringer 220-1 in subset 220 without any spacing between the surfaces of the composite member and the repair component. In another example, the repair component 511 positioned over the stringer 265-1 may fit relatively well, but include gaps between the repair component and the composite member. In some examples, the repair system 500 includes shims 550 and 555 which may be used to fill any gaps between a repair component and the composite member, as described in more detail in relation to
Method 600 begins at block 605 and includes selecting a repair component for a damaged section of a composite member from a repair component system based on an external cross-sectional profile of the composite member. For example, as shown in
The damaged section 711 has an external cross-sectional profile 716 which may include any of the profiles of the stringers discussed in relation to
Method 600 continues at block 610 and includes positioning the repair component over the damaged section such that a first flange section of the repair component is positioned on a first side of the composite member, a second flange section of the repair component is positioned over a second side of the composite member, and a repair section of the repair component, between the first flange section and the section flange section, is positioned over at least the damaged section of the composite member as shown in
For example, as shown in
In some examples, the repair section 825 includes an internal cross-sectional profile 826 defined on a repair surface 827 of repair section, where the repair surface faces an external surface 817 of the composite member 710, In some examples, the composite member 710 includes an external hat-stiffened structural profile defined on the external surface 817, and the internal cross-sectional profile 826 matches the external hat-stiffened structural profile 816 within a given tolerance. For example, as shown in
At block 615, method 600 includes attaching the positioned repair component to the composite member. For example, as shown in
In the current disclosure, reference is made to various aspects. However, it should be understood that the present disclosure is not limited to specific described aspects. Instead, any combination of the following features and elements, whether related to different aspects or not, is contemplated to implement and practice the teachings provided herein. Additionally, when elements of the aspects are described in the form of “at least one of A and B,” it will be understood that aspects including element A exclusively, including element B exclusively, and including element A and B are each contemplated. Furthermore, although some aspects may achieve advantages over other possible solutions and/or over the prior art, whether or not a particular advantage is achieved by a given aspect is not limiting of the present disclosure. Thus, the aspects, features, aspects and advantages disclosed herein are merely illustrative and are not considered elements or limitations of the appended claims except where explicitly recited in a claim(s). Likewise, reference to “the invention” shall not be construed as a generalization of any inventive subject matter disclosed herein and shall not be considered to be an element or limitation of the appended claims except where explicitly recited in a claim(s).
As will be appreciated by one skilled in the art, aspects described herein may be embodied as a system, method or computer program product. Accordingly, aspects may take the form of an entirely hardware aspect, an entirely software aspect (including firmware, resident software, micro-code, etc.) or an aspect combining software and hardware aspects that may all generally be referred to herein as a “circuit,” “module” or “system.” Furthermore, aspects described herein may take the form of a computer program product embodied in one or more computer readable storage medium(s) having computer readable program code embodied thereon.
Program code embodied on a computer readable storage medium may be transmitted using any appropriate medium, including but not limited to wireless, wireline, optical fiber cable, RF, etc., or any suitable combination of the foregoing.
Computer program code for carrying out operations for aspects of the present disclosure may be written in any combination of one or more programming languages, including an object oriented programming language such as Java, Smalltalk, C++ or the like and conventional procedural programming languages, such as the “C” programming language or similar programming languages. The program code may execute entirely on the user's computer, partly on the user's computer, as a stand-alone software package, partly on the user's computer and partly on a remote computer or entirely on the remote computer or server. In the latter scenario, the remote computer may be connected to the user's computer through any type of network, including a local area network (LAN) or a wide area network (WAN), or the connection may be made to an external computer (for example, through the Internet using an Internet Service Provider).
Aspects of the present disclosure are described herein with reference to flowchart illustrations and/or block diagrams of methods, apparatuses (systems), and computer program products according to aspects of the present disclosure. It will be understood that each block of the flowchart illustrations and/or block diagrams, and combinations of blocks in the flowchart illustrations and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions/acts specified in the block(s) of the flowchart illustrations and/or block diagrams.
These computer program instructions may also be stored in a computer readable medium that can direct a computer, other programmable data processing apparatus, or other device to function in a particular manner, such that the instructions stored in the computer readable medium produce an article of manufacture including instructions which implement the function/act specified in the block(s) of the flowchart illustrations and/or block diagrams.
The computer program instructions may also be loaded onto a computer, other programmable data processing apparatus, or other device to cause a series of operational steps to be performed on the computer, other programmable apparatus or other device to produce a computer implemented process such that the instructions which execute on the computer, other programmable data processing apparatus, or other device provide processes for implementing the functions/acts specified in the block(s) of the flowchart illustrations and/or block diagrams.
The flowchart illustrations and block diagrams in the Figures illustrate the architecture, functionality, and operation of possible implementations of systems, methods, and computer program products according to various aspects of the present disclosure. In this regard, each block in the flowchart illustrations or block diagrams may represent a module, segment, or portion of code, which comprises one or more executable instructions for implementing the specified logical function(s). It should also be noted that, in some alternative implementations, the functions noted in the block may occur out of the order noted in the Figures. For example, two blocks shown in succession may, in fact, be executed substantially concurrently, or the blocks may sometimes be executed in the reverse order or out of order, depending upon the functionality involved. It will also be noted that each block of the block diagrams and/or flowchart illustrations, and combinations of blocks in the block diagrams and/or flowchart illustrations, can be implemented by special purpose hardware-based systems that perform the specified functions or acts, or combinations of special purpose hardware and computer instructions.
While the foregoing is directed to aspects of the present disclosure, other and further aspects of the disclosure may be devised without departing from the basic scope thereof, and the scope thereof is determined by the claims that follow.
