Patent Application
20230249416
Composite materials, such as pre-impregnated (pre-preg) materials, are used in the formation of high-strength low-weight structures, such as, but not limited to, parts used to build aircraft and spacecraft. Pre-preg material is a composite made of fibers such as carbon, glass, aramid and the like, that are pre-impregnated with a resin system that is used to bond layers or sheets of the material together under heat and pressure. The pre-preg material is typically formed in sheets that are supplied to the manufacturer of the part in a continuous roll format of a fixed width. The manufacturer then cuts the sheets of pre-preg material and stacks of sheets of pre-preg material in particular orientations to create the desired shape and mechanical properties of the part. Heat and pressure are generally used to consolidate and bond the layers or sheets into a solid laminate. Existing processes tend to involve significant waste of composite material, which can amount to significant additional costs in manufacturing composite structures.
For the reasons stated above and for other reasons stated below that will become apparent to those skilled in the art upon reading and understanding the present specification, there is a need in the art for improvements of devices and methods for manufacturing composite structures.
The above-mentioned problems of current systems are addressed by embodiments of the present disclosure and will be understood by reading and studying the following specification. The following summary is made by way of example and not by way of limitation. It is merely provided to aid the reader in understanding some of the aspects of the disclosure.
In some embodiments, automated methods for manufacturing composite structures may comprise applying fibers having various predetermined lengths to a removable backing material to form a net shape or near net shape pattern for forming a composite structure having a varying transverse cross-section.
In further embodiments, sheets of composite material may comprise strips of composite material adhered to a backing material in a net shape or near net shape pattern for forming a composite structure with a varying transverse cross-section.
In yet further embodiments, automated methods of manufacturing sheets of composite material may comprise applying fibers having various predetermined lengths to a removable backing material to form a net shape or near net shape pattern for forming a composite structure having a varying transverse cross-section.
In some embodiments, a pattern preparation system may comprise a material placement device programmed and configured to apply fibers having various predetermined lengths to a removable backing material to form a net shape or near net shape pattern for forming a composite structure having a varying transverse cross-section.
In some embodiments, a forming system may comprise an indicia locating device programmed and configured to determine the location of an indicia and determine the location of a pattern of composite material on a removable backing material to align the pattern with the one or more forming surfaces of a tool.
The present disclosure can be more easily understood and further advantages and uses thereof more readily apparent, when considered in view of the detailed description and the following figures in which:
In accordance with common practice, the various described features are not drawn to scale but are drawn to emphasize specific features relevant to the present disclosure. Reference characters denote like elements throughout the figures and the text.
In the following detailed description, reference is made to the accompanying drawings, which form a part hereof, and in which is shown by way of illustration specific embodiments in which the disclosure may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the disclosure, and it is to be understood that other embodiments may be utilized and that changes may be made without departing from the spirit and scope of the present disclosure. The following detailed description is, therefore, not to be taken in a limiting sense, and the scope of the present disclosure is defined only by the claims and equivalents thereof.
The illustrations presented herein are not meant to be actual views of any particular systems, devices, or composite material patterns for fabricating composite structures, but are merely idealized representations employed to describe illustrative embodiments. The drawings are not necessarily to scale.
As used herein, the terms “substantially,” “about,” and “approximately” in reference to a given parameter means and includes to a degree that one skilled in the art would understand that the given parameter, property, or condition is met with a small degree of variance, such as within acceptable manufacturing tolerances. For example, a parameter that is substantially met may be at least about 90% met, at least about 95% met, at least about 99% met, or even at least about 100% met.
As used herein, relational terms, such as “first,” “second,” “top,” “bottom,” etc., are generally used for clarity and convenience in understanding the disclosure and accompanying drawings and do not connote or depend on any specific preference, orientation, or order, except where the context clearly indicates otherwise.
As used herein, the term “and/or” means and includes any and all combinations of one or more of the associated listed items.
Many composite components may have an inconsistent width along their length. For example, composite stiffeners for aircraft applications may have material removed in regions that are expected to take less loading, in order to reduce the weight of the aircraft. For another example, composite spars for aircraft wings may be tapered along their length to coincide with the tapered shape of the wings. Accordingly, to accommodate the variation in width, such composite components are conventionally manufactured from a sheet of material having a width equal to the widest part of the component. The material may then be trimmed to the final shape, with a substantial volume of extra material removed and discarded. This trimming of extra material may result in significant material waste, which may be costly.
Embodiments of the present disclosure involve methods and devices for the production of continuous or semi-continuous sheets of composite material, such as pre-preg material, with varying widths, varying profiles, and, if desired, varying orientation and varying thickness along the length of the sheet, which may be used directly to form composite structures, or stored in rolls for later use in forming composite structures.
Such sheets of composite material may be formed in a net shape or near net shape pattern for forming a composite structure having a varying transverse cross-section (e.g., a varying width).
Referring to
In some embodiments, the backing material 14 may be a pliable backing material such as polyethylene (PE). However, the present disclosure is not limited to PE backing material. An example range for a thickness of the backing material 14 may be between about 0.001 inch and about 0.006 inch. For example, the backing material 14 may be provided as a linear low-density PE film having a thickness of about 0.002 inch (2 mil).
Another example of a type of pliable material that could be used as the backing material 14 is polyurethane material. Polyurethane materials may be more pliable (e.g., elastic) than PE material and offer greater tear resistance and may offer advantages in forming complex shapes. Other types of plastics (e.g., polymers) can be used for the backing material 14 including, but not limited to, polyester, nylon and fluorinated hydrocarbons.
The backing material 14 may be provided from the supply roll 12 and may be passed through the surface treatment device 18 to treat a surface of the backing material 14. The treated backing material 14 may then proceed to the conveying table 20 for the application of composite material 26 thereon. The section of backing material 14 located on the conveying table 20 may be held in place with an applied vacuum for the placement of composite material 26 thereon by the material placement device 22.
In some embodiments, the material placement device 22 may comprise an automated fiber placement (AFP) device having an end effector or head, which may apply narrow strips of unidirectional tape. In additional embodiments, the material placement device 22 may comprise an automated tape laying (ATL) device, which may apply wider strips of unidirectional tape. The composite material 26 applied by the material placement device 22 may comprise strips of fibers, such as unidirectional fibers, which may be fully impregnated with resin, partially impregnated with resin, and/or only binder infused.
The material placement device 22 may apply segments of composite material 26 onto the backing material 14, the segments of composite material 26 having various predetermined lengths. The segments of composite material 26 may be positioned on the backing material 14 to form a sheet of composite material in a net-shape or near-net-shape pattern 40, 50, 60, 62 (see
The material placement device 22 may dispense composite material 26 from a composite material source 30, such as a spool of composite material, and cut the composite material 26 from the composite material source 30 to form segments of composite material 26. The material placement device 22 may cut and dispense the composite material 26 to follow a straight border (i.e., linear, see
Additionally, the pattern preparation system 10 may include a slitter 34 separate from the material placement device 22, which may be configured to perform straight slits and/or controlled edge trimming. A heater 36 may also be included with the pattern preparation system 10, which may heat strips of composite material 26 as they are placed by the material placement device 22 to promote adhesion.
In some embodiments, the material placement device 22 may include a marking device 32, which may apply one or more indicia 46 (see
In some embodiments, the material placement device 22 may be utilized to place strips of composite material 26 on the backing material 14 to form a pattern for the manufacturing of a composite aerospace structure, such as one more of a spar, a stiffener, and a frame. As shown in
As shown by the dashed line in
As shown in
After the patterns 40, 50, 60, 62 have been applied to the backing material 14, patterns 40, 50, 60, 62 and the backing material 14 may be rolled onto the take-up roll 16 for temporary storage. The take-up roll 16 may then be utilized as a material supply roll to feed the patterns 40, 50, 60, 62 onto a tool to form composite structures from the patterns 40, 50, 60, 62.
In some embodiments, a pattern 40, 50, 60, 62 (e.g., a sheet of composite material comprising strips of composite material adhered to a backing material in a net shape or near net shape pattern for forming a composite structure with a varying transverse cross-section) may be shaped less than 35% larger than the net shape of the composite structure to be formed (e.g., less than 35% of the composite material may be trimmed and removed as waste). In some embodiments, a pattern 40, 50, 60, 62 may be shaped less than 25% larger than the net shape of the composite structure to be formed (e.g., less than 25% of the composite material may be trimmed and removed as waste). In further embodiments, a pattern 40, 50, 60, 62 may be shaped less than 10% larger than the net shape of the composite structure to be formed (e.g., less than 10% of the composite material may be trimmed and removed as waste). In some embodiments, a pattern 40, 50, 60, 62 may be shaped less than 5% larger than the net shape of the composite structure to be formed (e.g., less than 5% of the composite material may be trimmed and removed as waste). In yet further embodiments, a pattern 40, 50, 60, 62 may be shaped at the net shape of the composite structure to be formed (e.g., none of the composite material is trimmed and removed as waste).
In some embodiments, a pattern 40, 50, 60, 62 may be shaped so that the outer margin is less than 30 mm larger than the net shape of the composite structure to be formed (e.g., a strip of material having a width less than 30 mm may be trimmed and removed as waste).
Accordingly, a method of manufacturing a sheet of composite material may comprise applying fibers having various predetermined lengths to a removable backing material, such as a polymer backing material, in a net-shape or near-net-shape pattern for forming a composite structure with a varying transverse cross-section.
As shown in
The indicia locating device 74 may be utilized to determine at least one of the longitudinal and/or transverse location of the indicia 46 for accurate placement of the pattern 40, 50, 60, 62 on the forming surfaces 78 of the tool 76. The indicia locating device 74 may comprise one or more of a camera, a laser, a light, a photovoltaic cell, and an optical sensor that may be utilized in conjunction with a control system 82 (e.g., a computer) to determine the location of the indicia 46, and thus the location of the pattern 40, 50, 60, 62.
Upon determining the location of the pattern 40, 50, 60, 62 on the backing material 14, the backing material 14 may be fed forward and/or backward, if needed, to a new longitudinal position relative to the tool 76 to align the pattern 40, 50, 60, 62 longitudinally with the tool 76. The pattern 40, 50, 60, 62 may additionally be aligned tangentially relative to the tool 76, such as by moving the backing material 14 and/or the tool 76 transversely relative to one another based on the detected location of the indicia 46 by the indicia locating device 74.
The pattern 40, 50, 60, 62 may then be positioned over the forming surfaces 78 (e.g., mandrel surfaces) of the tool 76 and forming devices 84, such as rollers, squeegees, wipers, fingers, and/or brushes, may press on the backing material 14 to press and form the pattern 40, 50, 60, 62 onto the forming surfaces 78. After the pattern 40, 50, 60, 62 is pressed and formed onto the forming surfaces 78, the backing material 14 may be removed from the pattern 40, 50, 60, 62 and transported to and stored on a backing take-up roll 80. Once all of the desired layers of patterns 40, 50, 60, 62 have been pressed onto forming surfaces 78 of the tool 76, the composite material may be removed for further processing (such as may be the case for a thermoplastic composite or a dry fiber preform) or further processed on the tool 76 (such as may be the case for thermoset composite or dry fiber preform). Once the composite material has been processed appropriately as described above, it may be removed from the tool 76 and trimmed, if needed, to form a composite part with a varying transverse cross-section.
The embodiments of the disclosure described above and illustrated in the accompanying drawing figures do not limit the scope of the invention, since these embodiments are merely examples of embodiments of the invention, which is defined by the appended claims and their legal equivalents. Any equivalent embodiments are intended to be within the scope of this disclosure. Indeed, various modifications of the present disclosure, in addition to those shown and described herein, such as alternative useful combinations of the elements described, may become apparent to those skilled in the art from the description. Such modifications and embodiments are also intended to fall within the scope of the appended claims and their legal equivalents.
