Patent Publication Number: US-2021188365-A1

Title: Composite structures with embedded veils for anchoring fasteners

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     This application claims priority to U.S. Provisional Patent Application Ser. No. 62/951,041, filed Dec. 20, 2019, the disclosure of which is hereby expressly incorporated by reference herein in its entirety. 
    
    
     FIELD OF THE DISCLOSURE 
     The present disclosure relates generally to composite structures and methods of making the same. More particularly, the present disclosure relates to composite structures for use in cargo vehicles and other applications having embedded anchors and methods of making the same. 
     BACKGROUND OF THE DISCLOSURE 
     Cargo vehicles are used in the transportation industry for transporting many different types of cargo. Certain cargo vehicles may be refrigerated and insulated to transport temperature-sensitive cargo. Cargo vehicles may be constructed using composite materials, which may lead to an absence of or reduction in metallic and wood materials and associated advantages, including simplified construction, thermal efficiency, reduced water intrusion and corrosion, and improved fuel efficiency through weight reduction, for example. However, such cargo materials must be sufficiently strong and durable to withstand the demands of normal use, both exteriorly (e.g., weather, road conditions, other vehicles) and interiorly (e.g., cargo, forklifts). 
     SUMMARY OF THE DISCLOSURE 
     A composite structure of a cargo body and a method of making the same are disclosed. The composite structure includes at least one anchor embedded between fiber-reinforced polymer (FRP) layers. The embedded anchor includes a porous veil of nonwoven fibers in a polymer-rich matrix. Accessories may be coupled to the composite structure by anchoring mechanical fasteners into the embedded anchor. 
     According to an exemplary embodiment of the present disclosure, a laminated composite structure of a cargo body is provided, the composite structure including a core layer including an inner foam core surrounded by a first fiber-reinforced polymer, an outer skin layer coupled to the core layer and including a second fiber-reinforced polymer, an inner skin layer coupled to the core layer and including a third fiber-reinforced polymer, and at least one anchor embedded between the first fiber-reinforced polymer and an adjacent one of the second and third fiber-reinforced polymers, wherein the at least one anchor includes a porous veil of nonwoven fibers. 
     According to another exemplary embodiment of the present disclosure, a laminated composite structure of a cargo body is provided, the composite structure including a core layer, an outer skin layer coupled to the core layer, an inner skin layer coupled to the core layer, an accessory coupled to the outer or inner skin layer with a mechanical fastener, and at least one anchor embedded between the core layer and the outer or inner skin layer and receiving the mechanical fastener. 
     According to yet another exemplary embodiment of the present disclosure, a method of manufacturing a composite structure of a cargo body is provided, the method including the steps of applying a gel-coat resin onto a mold surface to form a first gel coat, applying a first reinforcing fiber layer onto the first gel coat, arranging a core layer including a plurality of preforms on the first reinforcing fiber layer, applying at least one porous veil of nonwoven fibers adjacent to the preforms, applying a second reinforcing fiber layer onto the preforms, applying a laminating resin to wet-out the first reinforcing fiber layer, the second reinforcing fiber layer, and the veil, and curing the gel-coat and laminating resins. 
     Additional features and advantages of the present invention will become apparent to those skilled in the art upon consideration of the following detailed description of the illustrative embodiments exemplifying the best mode of carrying out the invention as presently perceived. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The foregoing aspects and many of the intended advantages of this invention will become more readily appreciated as the same becomes better understood by reference to the following detailed description when taken in conjunction with the accompanying drawings. 
         FIG. 1  is a perspective view of a cargo vehicle having a cargo body with having a floor, a roof, right and left sidewalls, and a front wall; 
         FIG. 2  is a cross-sectional view of the right sidewall of  FIG. 1 , which is a composite structure with embedded anchors; 
         FIG. 3  is a perspective view inside the cargo body of  FIG. 1 , which shows interior accessories fastened to the embedded anchors of the right sidewall; and 
         FIG. 4  is a microscopic image of a fabric veil for the embedded anchors. 
     
    
    
     Corresponding reference characters indicate corresponding parts throughout the several views. Although the drawings represent embodiments of various features and components according to the present disclosure, the drawings are not necessarily to scale and certain features may be exaggerated in order to better illustrate and explain the present disclosure. The exemplification set out herein illustrates an embodiment of the invention, and such an exemplification is not to be construed as limiting the scope of the invention in any manner. 
     DETAILED DESCRIPTION OF THE DRAWINGS 
     For the purposes of promoting an understanding of the principals of the invention, reference will now be made to the embodiments illustrated in the drawings, which are described below. The embodiments disclosed below are not intended to be exhaustive or limit the invention to the precise form disclosed in the following detailed description. Rather, the embodiments are chosen and described so that others skilled in the art may utilize their teachings. It will be understood that no limitation of the scope of the invention is thereby intended. The invention includes any alterations and further modifications in the illustrative devices and described methods and further applications of the principles of the invention which would normally occur to one skilled in the art to which the invention relates. 
     1. Cargo Vehicle 
     Referring initially to  FIG. 1 , a cargo vehicle  100  is shown for supporting and transporting cargo. The illustrative straight frame vehicle  100  extends along a longitudinal axis L from a front end  102  to a rear end  104  and includes a motorized truck  106  that powers a plurality of wheels  108  or other traction devices, a chassis  110 , and a bumper assembly  120 . The illustrative vehicle  100  further includes a cargo body  130  having a floor  140  ( FIG. 2 ) for supporting cargo, a roof  150 , right and left sidewalls  1   60 R,  1   60 L, a front wall or nose  170 , and a rear door assembly  180  having a rear frame  182  and a door (not shown) to access the cargo body  130 . 
     In the illustrated embodiment of  FIG. 1 , cargo body  130  is an enclosed body that is supported atop chassis  110 . Cargo body  130  may be refrigerated and/or insulated to transport temperature-sensitive cargo. While the concepts of this disclosure are described in relation to a refrigerated truck body, it will be understood that they are equally applicable to other vehicles generally, and more specifically to conventional trailers (e.g., dry freight trailers, flatbed trailers, commercial trailers, small personal trailers) and/or box or van semi-trailers, and the like. Accordingly, those skilled in the art will appreciate that the present invention may be implemented in a number of different applications and embodiments and is not specifically limited in its application to the particular embodiments depicted herein. 
     2. Composite Sidewalls and Other Composite Structures 
     Cargo body  130  may be constructed, at least in part, of composite materials. For example, the floor  140 , roof  150 , right and left sidewalls  160 R,  160 L, and/or front wall  170  of the composite cargo body  130  may be constructed of composite materials. As such, the floor  140 , roof  150 , right and left sidewalls  160 R,  160 L, and/or front wall  170  of the composite cargo body  130  may be referred to herein as composite structures. Each composite structure may be a single, unitary component, which may be formed from a plurality of layers permanently coupled together. Exemplary composite materials for use in the composite cargo body  130  include fiber-reinforced polymers or plastics (FRPs), for example glass-fiber-reinforced polymers or plastics (GFRPs) and carbon-fiber-reinforced polymers or plastics (CRPs). 
     A laminated composite right sidewall  1   60 R is shown in cross-section in  FIG. 2 . Those skilled in the art will appreciate that the following teachings related to the right sidewall  160 R may also be applied to the floor  140 , roof  150 , left sidewall  160 L, and/or front wall  170  of the composite cargo body  130 . 
     The illustrative sidewall  160 R of  FIG. 2  includes a core layer  200 , an outer skin layer  210  that faces outwardly from the cargo body  130  ( FIG. 1 ) toward the surrounding environment, and an inner skin layer  220  that faces inwardly toward the cargo in cargo body  130  ( FIG. 1 ). Each of these laminated layers  200 ,  210 ,  220  is described further below. 
     Referring still to  FIG. 2 , the core layer  200  of the composite sidewall  160 R may include one or more structural supports or preforms. Exemplary preforms for use in core layer  200  include PRISMA® preforms provided by Compsys, Inc. of Melbourne, Fla. Each preform may include an inner foam core  202 , an intermediate layer  204 , and an outer FRP layer  206 , each of which is described further below. 
     The inner foam core  202  of each preform may include a self-expanding, self-curing structural foam material. Suitable foams include polyurethane foams, such as a methylene-diphenyl-methane diisocyanate (MDI) based rigid polyurethane foam, for example. 
     The outer FRP layer  206  (which may be referred to herein as the “first” FRP layer  206 ) of each preform may include a polymer matrix reinforced with fibers configured to enhance the structural properties of the surrounding polymer matrix. Suitable reinforcing fibers include glass fibers, carbon fibers, aramid fibers (e.g., Kevlar® fibers available from DuPont Protection Technologies of Richmond, Va.), linear polyethylene or polypropylene fibers (e.g., Spectra® fibers available from Honeywell International Inc. of Morris Plains, N.J.), or polyester fibers. The reinforcing fibers may be present in fabric form, which may be mat, woven, or knit, for example. Exemplary fabrics include chopped fiber fabrics, such as chopped strand mats (CSM), and continuous fiber fabrics, such as 0°/90° fiberglass fabrics, +45°/−45° fiberglass fabrics, +60°/−60° fiberglass fabrics, 0° warp unidirectional fiberglass fabrics, and other stitched fiber fabrics, for example. Exemplary fabrics are commercially available from Vectorply Corporation of Phenix City, Ala. and include the E-LM 1810 fiberglass fabric with 0° unidirectional fibers, the E-LTM 3610 fiberglass fabric with 0°/90° fibers, and the EL TM 2408 fiberglass fabric with 0°/90° fibers, for example. Such fabrics may have an area density of about 800 g/m 2  to about 1,500 g/m 2  or more. 
     The intermediate layer  204  of each preform may serve as a transition layer for coupling the inner foam core  202  to the outer FRP layer  206 . The intermediate layer  204  may be sufficiently porous to at least partially receive foam from the adjacent foam core  202  and the polymer matrix from the adjacent FRP layer  206 . The intermediate layer  204  may also be mechanically coupled (e.g., stitched) to the adjacent FRP layer  206  to simplify manufacturing, to ensure proper placement, and to prevent shifting and/or bunching. The intermediate layer  204  may be a nonwoven fabric with continuous or chopped fibers, which may be the same as or similar to the fabric described in Section 5 below. 
     The individual preforms of the core layer  200  may be designed to accommodate the needs of the particular application. For example, in areas of the final structure requiring more strength and/or insulation, a low-density foam core  202  may be replaced with a high-density foam core  202  or a hard, plastic block. The individual preforms of the core layer  200  may also be sized, shaped, and arranged in a manner that accommodates the needs of the particular application. For example, in areas of the final structure requiring less strength, the preforms may be relatively large in size, with the foam cores  202  spanning relatively large distances before reaching the surrounding layers  204 , 206 . By contrast, in areas of the final structure requiring more strength, the preforms may be relatively small in size, with the foam cores  202  spanning relatively small distances before reaching the surrounding layers  204 ,  206 . Stated differently, the preforms may be shaped as relatively wide panels in areas of the final structure requiring less strength and as relatively narrow support beams in areas of the final structure requiring more strength. 
     Referring still to  FIG. 2 , the outer skin layer  210  of the composite sidewall  1   60 R may include a FRP layer  212  and an outer gel coat  214 . The FRP layer  212  (which may be referred to herein as the “second” FRP layer  212 ) may be similar to the above-described first FRP layer  206 , including a polymer matrix reinforced with suitable reinforcing fibers. According to an exemplary embodiment of the present disclosure, a plurality of different reinforcing fiber layers may be stacked together and used in combination to form the FRP layer  212 . For example, a chopped fiber fabric (e.g., CSM) may be positioned adjacent to a continuous fiber fabric. In this stacked arrangement, the chopped fibers may help support and maintain the adjacent continuous fibers in place, especially around comers or other transitions. Also, the chopped fibers may serve as a web to resist column-type loads in compression, while the adjacent continuous fibers may resist flange-type loads in compression. Adjacent reinforcing fiber layers may be stitched or otherwise coupled together to simplify manufacturing, to ensure proper placement, and to prevent shifting and/or bunching. The outer gel coat  214  may be a polymer-rich or polymer-only layer that provides a smooth outer finish in a desired color. 
     Referring still to  FIG. 2 , the inner skin layer  220  of the composite sidewall  1   60 R may include a FRP layer  222  and an optional inner gel coat  224 . The FRP layer  222  (which may be referred to herein as the “third” FRP layer  222 ) may be similar to the above-described first and second FRP layers  206 ,  212 , including a polymer matrix reinforced with suitable reinforcing fibers. The inner gel coat  224  may be a polymer-rich or polymer-only layer similar to the above-described outer gel coat  214  that provides a smooth inner finish in a desired color. 
     The illustrative composite sidewall  160 R further includes one or more embedded anchors  400 ,  410  positioned between the core layer  200  and the adjacent skin layer  210 ,  220 . The embedded anchors  400 ,  410  are described further in Section 5 below 
     3. Composite Molding Method 
     The composite structures of the present disclosure, including the composite sidewall  160 R of  FIG. 2 , may be formed by a layered molding process. An exemplary molding process involves (1) applying a gel-coat resin onto a mold surface to form the outer gel coat  214 , (2) layering the reinforcing fibers of the outer FRP layer  212 , the preforms of the core layer  200 , the reinforcing fibers of the inner FRP layer  222 , and any other desired layers (e.g., embedded anchors  400 ,  410  of Section 5 below) onto the outer gel coat  214 , (3) wetting out the layers  212 ,  200 ,  222 , and any other applied layers (e.g., embedded anchors  400 ,  410  of Section 5 below) with at least one laminating resin to impregnate and/or coat the fibers, (4) optionally applying another gel-coat resin onto the layers  212 ,  200 ,  222  to form the inner gel coat  224 , and (5) curing the materials upon the mold surface (either sequentially and/or simultaneously) to form a single, integral, laminated composite sidewall  160 R. 
     The laminating resin of step (3) may be a typical thermosetting resin, such as a vinyl ester, epoxy resin, or unsaturated polyester resin, although thermoplastic resins are also contemplated. The gel-coat resin of steps (1) and (4) may be a typical polyester gel-coat resin or a co-cure resin containing one or more elastomer components, such as urethane, co-cured with one or more laminating resin components, such as a vinyl ester, epoxy resin, or unsaturated polyester components. Exemplary co-cure resins are disclosed in U.S. Pat. No. 9,371,468 and U.S. Publication No. 2016/0263873, the disclosures of which are hereby incorporated by reference in their entireties. 
     Additional information regarding the construction of composite structures is disclosed in the following patents, each of which is incorporated by reference in its entirety herein: U.S. Pat. Nos. 5,429,066, 5,664,518, 5,800,749, 5,830,308, 5,897,818, 5,908,591, 6,004,492, 6,013,213, 6,206,669, 6,496,190, 6,497,190, 6,543,469, 6,723,273, 6,755,998, 6,869,561, 6,911,252, 8,474,871, 10,239,265. 
     4. Sidewall Accessories 
     Referring next to  FIG. 3 , the interior cargo area of the cargo body  130  is shown, including the inner skin layer  220  of the right sidewall  1   60 R. The illustrative sidewall  1   60 R includes one or more interior accessories  300 ,  310  positioned against the inner skin layer  220  and fastened thereto using corresponding mechanical fasteners  302 ,  312 . Each illustrative accessory  300 ,  310  includes a large number of holes  304 ,  314  such that fasteners  302 ,  312  may be placed in desired locations. The fasteners  302 ,  312  may be selected to resist withdrawal from the sidewall  160 R, such as by modifying the fastener type (e.g., rivet, sheet metal screw, wood screw), size, pitch, and location. The interior accessories  300 ,  310  may also be adhered to the inner skin layer  220  of the sidewall  1   60 R to enhance the mechanical connection. 
     In the illustrated embodiment of  FIG. 3 , the first interior accessory  300  is an upper horizontal logistic track (e.g., “E-track”) fastened to the inner skin layer  220 , and the second interior accessory  310  is a lower horizontal logistic track also fastened to the inner skin layer  220 . Other suitable interior accessories include scuff plates  320 , lights (not shown), and shelves (not shown), for example. 
     The sidewall  1   60 R may also include exterior accessories coupled to the outer skin layer  210  ( FIG. 2 ) with mechanical fasteners and/or adhesives. Suitable exterior accessories include exterior lights (not shown), for example. 
     5. Embedded Anchors 
     Referring again to  FIGS. 2 and 3 , the composite sidewall  160 R includes the first embedded anchor  400  and the second embedded anchor  410 . The first embedded anchor  400  is positioned beneath the first accessory  300  to receive the corresponding fasteners  302  through the holes  304  of the first accessory  300 , through the inner skin layer  220 , and into the first embedded anchor  400 . Similarly, the second embedded anchor  410  is positioned beneath the second accessory  310  to receive the corresponding fasteners  312  through the holes  314  of the second accessory  310 , through the inner skin layer  220 , and into the second embedded anchor  410 . The embedded anchors  400 ,  410  may locally strengthen the composite sidewall  1   60 R and resist withdrawal of the corresponding fasteners  302 ,  312 , similar to a wood stud behind drywall. 
     The embedded anchors  400 ,  410  are selectively positioned to receive the fasteners  302 ,  312  of the corresponding accessories  300 ,  310 . Stated another way, the embedded anchors  400 ,  410  are selectively positioned in alignment with one or more holes  304 ,  314  of the corresponding accessories  300 ,  310 . As shown in  FIG. 3 , the embedded anchors  400 ,  410  span continuously along substantially the entire length of the corresponding accessories  300 ,  310  and the composite sidewall  160 R to receive fasteners  302 ,  312  in any of the holes  304 ,  314 . However, it is also within the scope of the present disclosure to position discrete anchors beneath select holes  304 ,  314 . 
     The areas of the composite sidewall  160 R that do not receive fasteners  302 ,  312  need not be further strengthened. As shown in  FIGS. 2 and 3 , the embedded anchors  400 ,  410  span only a partial height of the composite sidewall  160 R, leaving anchor-free areas  420 ,  422 ,  424  above, between, and below the anchors  400 ,  410 , respectively. The ability to selectively position the anchors  400 ,  410  may improve the anchoring of fasteners  302 ,  312  where necessary while also minimizing the weight and thickness of the composite sidewall  1   60 R. 
     As shown in  FIG. 2 , the embedded anchors  400 ,  410  may be positioned between the preforms of the core layer  200  and the desired skin layer  210 ,  220 . Thus, the embedded anchors  400 ,  410  may be placed in their desired locations during the layering step (2) of Section 3 above. In this way, the molding method may be customized to accommodate the needs of the particular sidewall  160 R and its particular accessories  300 ,  310 . Also, this custom molding method may be performed without having to manufacture or obtain custom preforms, for example. 
     According to an exemplary embodiment of the present disclosure, and as shown in  FIG. 4 , each embedded anchor  400 ,  410  includes a veil  430  of fibers  432  integrated into the surrounding polymer matrix. The veil  430  may be a nonwoven fabric with continuous or chopped fibers  432 . The fibers  432  may be bonded together thermally (e.g., calendered), mechanically (e.g., needle punched, spunbond), and/or chemically. The fibers  432  may be thermoplastic monofilaments, such as polyester (e.g., polyethylene terephtalate (PET)), polyethylene, polystyrene, or polypropylene monofilaments, or combinations thereof including bi-filaments, for example. Other suitable fibers  432  include aramid, nylon, acrylonitrile butadiene styrene (ABS), for example. In certain embodiments, the veil  430  may include a polyester-based spunbound or needle-punched fabric available from Oxco, Inc. of Charlotte, N.C. (e.g., Product No. Al 19N14WT1Cl), a polyester-based Trevira fabric available from Trevira GmbH in Bobingen, Germany, a polyester-based spunbound Evalith® fabric available from Johns Manville of Denver, Colo., a polyethylene-based Spectra® fabric available from Honeywell International Inc. of Morris Plains, N.J., or a polyester-based Avelle® fabric available from Xamax Industries, Inc. of Seymour, Conn., for example. 
     As shown in  FIG. 4 , the veil  430  is a porous material having an open, non-bunched arrangement of fibers  432  with pores  434  therebetween that accept a high weight ratio of resin to fibers  432 . In some instances, the weight ratio of resin to fibers  432  may be about 5:1, about 7:1, about 10:1, or more. Typically, such veils are used at or near a structure&#39;s surface to form a smooth, polymer-rich surface finish that conceals and attaches to the underlying reinforcing layers. However, in this case, the veil  430  may form polymer-rich embedded anchors  400 ,  410 . The veil  430  may be more porous than typical reinforcing fiber layers (e.g., FRP layers  206 ,  212 ,  222  of  FIG. 2 ), where the weight ratio of resin to fibers  432  may be about 1:1, about 1:2, or more. The veil  430  may be pre-impregnated or impregnated with a different resin or a different co-cure strain tuning level compared to the resin of the adjacent FRP layers  206 ,  212 ,  222  (See Section 3 above) to optimize the performance and damage resistance of the veil  430 . In one example, the veil  430  may be pre-impregnated or impregnated during lamination with a thermoplastic resin different from the thermoset resin of the adjacent FRP layers  206 ,  212 ,  222 . In another example, the veil  430  may be pre-impregnated or impregnated during lamination with a resin having a higher co-cure level than the resin of the adjacent FRP layers  206 ,  212 ,  222  to improve fastener toughness and crack resistance. 
     The fibers  432  of the veil  430  may be more flexible than those of typical reinforcing layers (e.g., FRP layers  206 ,  212 ,  222  of  FIG. 2 ). Typical reinforcing fibers may be rigid, structural fibers like glass configured to strengthen the surrounding polymer matrix. By contrast, the fibers  432  of the veil  430  may be flexible and considered non-reinforcing. Without wishing to be bound by theory, the flexible fibers  432  may have sufficient toughness to mitigate damage during installation of the fasteners  302 ,  312  and may deform and/or move to accommodate the fasteners  302 ,  312  ( FIG. 3 ) while serving as crack arresters that help prevent the spread of cracks through the surrounding polymer matrix. The flexibility of the veil  430  may be measured in terms of tensile strength, elongation, and Young&#39;s Modulus, for example. In certain embodiments, the veil  430  may have a tensile strength before lamination of about 20 lbs to about 40 lbs, such as about 30 pounds, and may exhibit elongation before lamination of about 25% to about 200%, such as about 40% to about 100%. The veil  430  may have non-uniform flexibility, such that these values vary when measured in the machine direction (MD) and the cross direction (CD). In one example, the MD tensile strength may exceed the CD tensile strength, and the CD elongation may exceed the MD elongation. The tensile strength and elongation may be measured according to ASTM D4632. 
     The veil  430  may have a lower area density than typical reinforcing fiber layers (e.g., FRP layers  206 ,  212 ,  222  of  FIG. 2 ). In certain embodiments, the veil  430  may have an area density of about 500 g/m 2  or less, such as about 10 g/m 2  to about 500 g/m 2 , or about 30 g/m 2  to about 300 g/m 2 , or about 30 g/m 2  to about 200 g/m 2 , or about 50 g/m 2  to about 150 g/m 2 , or about 110 g/m 2  to about 150 g/m 2 . The area density may be measured according to ASTM D461. 
     The veil  430  may also be thinner than typical reinforcing fiber layers. In certain embodiments, the veil  430  may have a thickness of about 0.060 inches (60 mils) or less, such as about 0.005 inches (5 mils) to about 0.055 inches (55 mils), about 0.015 inches (15 mils) to about 0.045 inches (45 mils), or about 0.025 inches (25 mils) to about 0.035 inches (35 mils). Alternatively, the veil  430  may be the same thickness or thicker than typical reinforcing fiber layers. In these embodiments, the veil  430  may have a thickness of about 0.10 inches (100 mils) or more, such as about 0.10 inches (100 mils) to about 0.30 inches (300 mils), or about 0.15 inches (150 mils) to about 0.25 inches (250 mils), or about 0.20 inches (200 mils). The thickness of the veil  430  may be increased by using multiple layers of material, with each layer optionally pre-impregnated or impregnated with a different resin or a different co-cure strain tuning level compared to other layers of the veil  430 . The thickness may be measured according to ASTM D5729. 
     The embedded anchors  400 ,  410  may be modified to accommodate various fasteners and their corresponding attachments. More specifically, the properties of the veil  430 , the properties of the incorporated resin, the number, the size, the shape, and the location of the embedded anchors  400 ,  410  may be modified to accommodate various fasteners and their corresponding attachments to the floor  140  (e.g., suspension, landing gear, fuel tank), roof  150 , left sidewall  1   60 L (e.g., scuff plates  320 , lights, shelves, other accessories), and/or front wall  170  (e.g., thermal control unit) of the composite cargo body  130 . For example, as the fasteners  302 ,  312  increase in size, the veils  430  of the corresponding embedded anchors  400 ,  410  may also increase in thickness to support heavier loads from the attachments. In certain embodiments, the attachment may be an adjacent composite panel of the composite cargo body  130 , such that embedded anchors  400 ,  410  may be placed continuously or discretely along joints between the floor  140 , roof  150 , sidewalls  160 R,  160 L, and/or front wall  170  to receive fasteners for assembling the adjacent panels. 
     While this invention has been described as having an exemplary design, the present invention may be further modified within the spirit and scope of this disclosure. This application is therefore intended to cover any variations, uses, or adaptations of the invention using its general principles. Further, this application is intended to cover such departures from the present disclosure as come within known or customary practices in the art to which this invention pertains.