LIGHTWEIGHT STRUCTURAL REINFORCEMENT

FIELD

[001] The present invention generally relates to a structural reinforcement, and more particularly, to lightweight structural reinforcements utilizing a structural adhesive material curable at ambient temperature.

BACKGROUND

[002] Transportation vehicles frequently utilize structural members to form, support, reinforce, or a combination thereof certain vehicle structures. Unfortunately, such members tend to be formed of relatively heavy materials such as metal, adding undesirable weight to the vehicle. For some applications, it has become popular in recent years to employ a composite structure as part of the reinforcement. However, these materials may often still add significant weight and can be costly and time consuming to manufacture. Moreover, the materials used to form the structural members may be structurally deficient when compared to the conventional heavier materials, resulting in a weaker structure unable to withstand a desired load, unable to perform properly, or both. Additionally, it may be difficult to provide sufficient structural support to certain vehicle structures using more lightweight materials, thereby increasing the risk of damage or breakage of the structural members, the vehicle structures being supported by the structural members, or both. [003] One particular vehicle reinforcement provides structural reinforcement to a bus in order to meet vehicle rollover specifications. Due to a higher center of gravity along with other characteristics of the vehicle design, a bus may often be more prone to rollover accidents. As a result, it is often necessary that bus designs comply with various rollover test specification requirement, such as those found Automotive Industry Standards (ATS) AIS-031 and Urban Bus Specification (UBS) - II, which are incorporated herein in their entirety for all purposes. Unfortunately, lightweight materials conventionally implemented as an improvement in some vehicles may be unable to meet the aforementioned requirements for bus rollover. Additionally, due to the bus structure being more complex than other types of transportation vehicles, it may be difficult for improvements to be made with respect to the materials used for the structure of the bus.

[004] One additional reinforcement provides an intrusion guard along an underbody of a vehicle. The intrusion guard may be attached to an underrun along a front portion, a rear portion, a side portion, or a combination thereof of a vehicle to prevent an additional vehicle from being compressed beneath the vehicle’s underbody during a collision (i.e., to prevent “submarining”). The intrusion guard may provide a crumple zone that gradually stops the additional vehicle before it reaches the clearance gap between the vehicle and the ground. However, intrusion guards may be frequently derived using similar techniques and materials as illustrated above. Examples of vehicle barrier systems, including but not limited to intrusion guard structures, may be found in U.S. Provisional Patent Application No. 63/312,434, fded on February 22, 2022; U.S. Patent Application No. 17/598,755, filed on September 27, 2021; and U.S. Patent Nos. 7,284,788; 7,766,403; and 9, 623, 820; all of which are incorporated herein in their entirety for all purposes. Additionally, such intrusion guards may be required to meet various test specifications, such as those found in India Standard 14812: 2005 for Automotive Vehicles - Rear Underrun Protective Device - General Requirements, which is incorporated herein in its entirety.

[005] Moreover, while vehicle reinforcement has been discussed above, it is of note that similar issues may arise in the construction industry. Various structures, including but not limited to, residential and commercial buildings, may also utilize various materials to form an overall structure of the building. Such a structure may be adapted to meet various building specifications that require certain load and/or strain requirements, among other structural characteristics. However, similar to the transportation vehicle industry, conventional building materials may be relatively heavy materials such as metal, adding undesirable weight to the buildings. Moreover, such materials can be difficult to source due to material shortages or may be a challenge to replace with more lightweight or cost-effective materials given the strenuous reinforcement requirements needed.

[006] Based on the above, there remains a need for an improved vehicle or building structural reinforcement. What is needed is a structural reinforcement formed using one or more lightweight composite materials. There remains a need for a structural reinforcement that is lightweight yet provides sufficient structural reinforcement to meet vehicle or building requirements. What is needed is a structural reinforcement using one or more lightweight composite materials that provide sufficient structural support during vehicle rollover and/or building construction. Additionally, there remains a need for a structural reinforcement that is simple to manufacture and cost effective. What is needed is a structural reinforcement that may be formed and/or cured at ambient temperatures, thereby minimizing and simplifying a manufacturing or construction process.

SUMMARY

[007] The present teachings meet one or more of the present needs by providing a vehicle frame comprising: (a) a structural member having a cavity extending through at least a portion of the structural member; and (b) a structural reinforcement positioned with the cavity of the structural member; wherein the structural reinforcement is a curable adhesive cured at ambient temperature.

[008] The structural reinforcement may be positioned within the structural member at a joint between the structural member and one or more additional structural members. The structural reinforcement may be injected into the cavity prior to curing. The structural reinforcement may be at least partially secured in place by a stopper located adjacent to the structural reinforcement within the cavity of the structural member. The stopper may be positioned within the cavity prior to injection of the structural reinforcement to prevent the structural reinforcement from flowing beyond the stopper. Similarly, stoppers may be positioned on opposing sides of the structural reinforcement to define a height of the structural reinforcement once cured. Moreover, the stopper may be a shim, wedge, or panel inserted into the cavity of the structural member.

[009] The structural member may be a hollow metal tube. The structural member may include opposing pieces of outer shell joined together to form a cavity therein. The structural reinforcement may be injected into the cavity through an aperture located along the structural member.

[0010] The structural reinforcement may be expandable, foamable, or both. The structural reinforcement may have an expansion rate of about 50% or more, about 100% or more, or preferably about 145% or more. The structural reinforcement may be flame retardant, chemical resistant, or both. Moreover, the structural reinforcement may only reinforce a portion of the cavity of the structural member in a localized region.

[0011] The vehicle frame may be adapted to reinforce a bus. The vehicle frame may meet rollover requirements per Automotive Industry Standards (AIS) AIS-031, Urban Bus Specification (UBS) - II, or both. Additionally, the structural reinforcement may reinforce a joint between the structural member and a crossmember of the vehicle frame, whereby the structural member may be a pillar of the vehicle frame.

[0012] The present teachings may also meet one or more of the present needs by providing a structural member having a cavity therein, wherein the cavity is at least partially fdled with a structural reinforcement that is a curable structural adhesive cured at ambient temperature. The structural member may be adapted to reinforce a vehicle, reinforce a building structure, or both.

[0013] Furthermore, the present teachings meet one or more of the present needs by providing: an improved vehicle or building structural reinforcement; a structural reinforcement formed using one or more lightweight composite materials; a structural reinforcement that is lightweight yet provides sufficient structural reinforcement to meet vehicle or building requirements; a structural reinforcement using one or more lightweight composite materials that provide sufficient structural support during vehicle rollover and/or building construction; a structural reinforcement that is simple to manufacture and cost effective; a structural reinforcement that may be formed and/or cured at ambient temperatures, thereby minimizing and simplifying a manufacturing or construction process; or a combination thereof.

DESCRIPTION OF THE DRAWINGS

[0014] FIG. 1 is a perspective view of a vehicle with structural members.

[0015] FIG. 2 is a perspective view of a vehicle frame in accordance with the present teachings.

[0016] FIG. 3 is a close-up perspective view of a vehicle frame structurally reinforced in accordance with the present teachings.

[0017] FIG. 4 is cross-section 4-4 of FIG. 3.

[0018] FIG. 5 is a perspective view of a sectioned structural member having a structural reinforcement in accordance with the present teachings.

[0019] FIG. 6A is a perspective view of a structural member free of a structural reinforcement in accordance with the present teachings.

[0020] FIG. 6B is a perspective view of a structural member having a structural reinforcement in accordance with the present teachings.

[0021] FIG. 6C is a perspective view of a structural member having a structural reinforcement in accordance with the present teachings. [0022] FIG. 7A is a perspective view of simulated rollover results of a vehicle with a vehicle frame free of structural reinforcement in accordance with the present teachings.

[0023] FIG. 7B is a perspective view of simulated rollover results of a vehicle with a vehicle frame having structural reinforcement in accordance with the present teachings.

[0024] FIG. 8 is a graph illustrating bend testing results of various samples.

[0025] FIG. 9A is a graph illustrating 3-point bending test results of a conventional structural member.

[0026] FIG. 9B is a graph illustrating 3-point bending test results of a structural member reinforcement in accordance with the present teachings.

[0027] FIG. 10 is a graph illustrating 3-point bending test results for peak force of various samples compared to conventional structural members.

[0028] FIG. 11 is a graph illustrating 3-point bending test results for energy absorption of various samples compared to conventional structural members.

[0029] FIG. 12 is a perspective view of a structural member of a vehicle intrusion guard having a structural reinforcement.

[0030] FIG. 13 is cross-section 13 of the vehicle intrusion guard of FIG. 12.

[0031] FIG. 14 is a perspective view illustrating impact testing setup of a structural member of a vehicle intrusion guard.

DETAILED DESCRIPTION

[0032] The explanations and illustrations presented herein are intended to acquaint others skilled in the art with the invention, its principles, and its practical application. The specific embodiments of the present invention as set forth are not intended as being exhaustive or limiting of the invention. The scope of the invention should be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled. The disclosures of all articles and references, including patent applications and publications, are incorporated by reference herein in their entirety for all purposes. Other combinations are also possible as will be gleaned from the following claims, which are also hereby incorporated by reference into this written description herein in their entirety.

[0033] The teachings herein are directed toward structural members and reinforcement thereof. The structural members may function to form a structure of a vehicle, building, or both. It should be noted that, while examples and discussion herein may be directed to a vehicle structure for illustrative purposes, the teachings herein for structural reinforcement are not intended to be limited to only vehicle structure reinforcement. That is, the structural members and reinforcement thereof may also be applicable to various industries beyond the transportation industry, such as residential and commercial construction industries, the agriculture industry, or a combination thereof. As such, the teachings herein may advantageously be adaptable to various applications to meet the demands of each industry.

[0034] This application claims the benefit of the priority date of India Application No. 202231023809 filed on April 22, 2022. The contents of that application are incorporated by reference herein in their entirety and for all purposes.

[0035] The structural members may function to provide or form a portion of structure. The structural members may form an inner cabin or passenger area, such as those found on a passenger bus or vehicle. As such, the structural members may be adapted to maintain the integrity of the structure. By way of example, the structural members may form a vehicle frame for a bus or other type of vehicle. The structural members may thus be required to meet vehicle specifications, such as crash test specifications. For example, one particular point of focus for transportation vehicles such as buses is rollover safety. During a vehicle rollover situation, it may be required that the structural members forming the vehicle frame may maintain structural integrity to specified degree. That is, the structural members may withstand impact upon rollover without deforming beyond a designated limit.

[0036] As mentioned above, the structural members may be interconnected to form an overall frame, such as a vehicle frame. However, other frames, such as the framing or a building, may also be applicable. As such, the teachings herein are not limited to reinforcing any one particular type of structural member. That is, the structural members may be any size, shape, dimensions, or a combination thereof. The structural members may be hollow, partially hollow, may have one or more cavities, may include one or more solid portions, or a combination thereof. The structural members may include one or more openings, one or more channels, one or more linear segments, one or more arcuate portions, one or more bends, or a combination thereof. The structural members may also be one or more materials. For example, the structural members incorporating the teachings herein may be metallic, non-metallic (e.g., a composite material), or a combination thereof (e.g., a joint combining a composite structural member with a metallic member). [0037] The structural members may be a tube. As such, the structural member may include a cavity formed along at least a portion of an interior of the structural member. The tube may be any material, yet it is envisioned that many conventional materials used in vehicle or building construction may be a metal tubing, such as round or square tubing. Similarly, any grade of material (e g., thickness, force resistance, etc., metal type) may also be used with the present teachings.

[0038] Due to the structural members potentially being interconnected to form an overall frame, one or more different structural members or shapes thereof may be utilized. For example, the structural members may include, but are not limited to, substantially vertical pillars, substantially horizontal members, crossmembers, or a combination thereof. The vertical pillars and horizontal members may be vertical and horizontal, respectively, relative to a floor of the vehicle and/or the ground underneath the vehicle. Similarly, the crossmembers may extend transversely between pillars and/or horizontal members across a width of the vehicle. However, the aforementioned structural members may extend at any desired angle, in any desired direction, or both. Thus, the various structural members may be modified or interconnected to form various shapes for a frame, such as a vehicle frame.

[0039] The structural members may be interconnected by a joint. The joint may function to join structural members to each other. The joint may be a mechanical joint, such as a weld, mechanical fastener, or both. The joint may also be an adhesive joint bonding or adhering multiple structural members to each other. However, any type of joint may exist to connect the structural members to each other.

[0040] In vehicle and/or building frames, joints may frequently be a point of weakness due to the interconnection of the structural members. As a result, conventional frames may often require secondary operations in an attempt to strengthen the joints. For example, gussets, ribs, mechanical fasteners, additional welds, or a combination thereof may be completed as a secondary operation during manufacturing of the frame to try and improve structural integrity. However, such operations may be costly, take excess time, or both. Similarly, the secondary attempts at strengthening the joints may also only incrementally improve the structural integrity of the joints. Additionally, it should be noted that similar operations may also be completed along other areas or regions of the structural members or frames beyond just the j oints themselves. [0041] To improve the aforementioned limitations of conventional frames, the present teachings contemplate incorporating a structural reinforcement within the structural members. As discussed above, the structural members may include a cavity, hollow portion, channel, or a combination thereof. It is envisioned that the structural reinforcement may be located within such a cavity, hollow portion, channel, or combination thereof. However, the structural reinforcement may not be limited to the aforementioned locations and may instead or also be positioned along an exterior of the structural members.

[0042] The structural reinforcement may be a solid member inserted or adjoined to the structural member. For example, the structural reinforcement may be a sleeve wrapped around at least a portion of the structural member or may be a core inserted into a portion of the structural member.

[0043] However, it is particularly envisioned that the structural reinforcement may be an adhesive material adapted to at least partially adhere to the structural member for reinforcement. As such, the structural reinforcement may be a structural adhesive that may provide one or more material properties to further improve the structural integrity of one or more structural members. Beneficially, the structural reinforcement may be tunable to provide desired material properties for certain applications. For example, the structural reinforcement may be tunable to provide a desired foaming or expansion rate, curing time, stiffness, tackiness, viscosity, other properties, or a combination thereof. One such composition of a structural reinforcement may include an ester epoxy composition. Examples of such structural reinforcement materials may be found in U.S. Publication Nos. 2021/0395478, 2022/0025172, and 2022/0089859, all of which are incorporated herein in their entirety for all purposes.

[0044] As discussed above, the structural reinforcement may be applied as an adhesive material. Advantageously, the adhesive material may be applied through injection means directly into the structural reinforcement, thereby eliminating secondary manufacturing processes. For example, the structural reinforcement may be injected into a cavity or hollow portion of a structural member as a viscous material that may be flowable through the cavity or hollow portion. As such, the structural reinforcement may be injected through an entry point, such as an aperture (e.g., hole, cutout, window, etc.) in the structural member to flow and reinforce a larger area of the structural member beyond the entry point. Thus, the structural member may maintain its overall integrity and require little to no fabrication for application of the structural reinforcement to the structural member.

[0045] Similarly, it is envisioned that the structural reinforcement may be cured and/or activated without additional manufacturing steps. That is, the structural reinforcement may be cured or activated at an ambient temperature without the need of an outside chemical agent or heightened temperature for curing and/or activation.

[0046] The curing, foaming, or both may occur at a temperature of about 50 °C or less, 40 °C or less, about 30 °C or less, about 20 °C or less, or about 0 °C or less. The curing, foaming, or both may occur at a temperature of about 0 °C or more, about 10°C or more, or even about 20 °C or more. The curing, foaming, or both may occur at a temperature from about 10 °C to about 50 °C, or even more. The curing, foaming, or both may occur at a temperature of about 10 °C. The curing, foaming, or both may occur at room temperature (e.g., at a temperature of about 15 °C to about 25 °C). The curing, foaming, or both may occur at a temperature of about 23 °C. The curing and foaming may occur at different temperatures or at substantially the same temperature. [0047] The curing, foaming, or both may also occur within desired humidity conditions. However, advantageously, it is envisioned that the structural reinforcement may be adapted to cure, foam, or both in less regulated and/or controlled environments. That is, the curing, foaming, or both may occur in an environment having a humidity of about 0% or more, about 30% or more, or about 60% or more. The curing, foaming, or both may occur in an environment having a humidity of about 100% or less, about 70% or less, or about 30% or less. Thus, it may be gleaned that the curing, foaming, or both of the structural reinforcement may advantageously occur at heightened humidity without requiring the environment to regulated and/or controlled.

[0048] The present teachings contemplate a relatively fast curing time, foaming time, or both of the structural reinforcement as compared to other conventional cure agents or cure systems that occur without the addition of a stimulus (e.g., at room temperature). The cure time of the structural reinforcement may be 75 minutes or less, 50 minutes or less, 30 minutes or less, 20 minutes or less, 2 minutes or more, 8 minutes or more, or even 16 minutes or more. The cure time of the structural reinforcement may be from about 5 minutes to about 20 minutes. The cure time of the structural reinforcement may be about 10 minutes. The cure time of the structural reinforcement may be about 7 minutes. The cure time of the structural reinforcement may be about 5 minutes. The curing and foaming may occur at different times or at substantially the same time. [0049] Foaming may begin before complete cure of the structural reinforcement. The foaming time (i.e., the time frame within which the structural reinforcement actively foams) of the structural reinforcement may be 30 minutes or less or even 20 minutes or less. The foaming time of the structural reinforcement may be from about 1 minute to about 10 minutes. The foaming time of the structural reinforcement may be about 5 minutes. The foaming time of the structural reinforcement may be about 7 minutes.

[0050] As may be gleaned above, the structural reinforcement may be tunable to meet various application demands. For example, foaming of the structural reinforcement may be tuned to reach a desired density of the structural reinforcement after curing. The structural reinforcement may have a cured density of about 0.1 grams per cubic centimeter (g/cc) or more, about 0.3 g/cc or more, or about 0.5 g/cc or more. The structural reinforcement may have a cured density of about 1 g/cc or less, about 0.8 g/cc or less, or about 0.6 g/cc or less. For example, the structural reinforcement may have a cured density of about 0.5 g/cc to about 0.7 g/cc.

[0051] Similarly, in addition to cured density of the structural reinforcement, various other material properties may be tuned such as those mentioned above. It is envisioned that some or all tunability of the structural reinforcement may be dictated during mixing of the structural reinforcement prior to curing. For example, the structural reinforcement may be a two-part material having a Part A and a Part B. A mixing ratio between Parts A and B may help tune the resultant structural reinforcement for desired material properties once cured.

[0052] Turning now to the figures, FTG. 1 illustrates a perspective view of a vehicle 10. While the present teachings may be applicable to any vehicle 10, a bus is shown for illustrative purposes. As shown, the vehicle 10 may include a plurality of structural members 14 adapted to form a structure of the vehicle 10. For example, the structural members 14 may form a general shape of the vehicle 10 and at least partially create a passenger area within the vehicle 10 for one or more occupants. As a result, the structural members 14 may be required to comply with various vehicle 10 safety standards, such as ensuring the safety of the occupants during a vehicle 10 crash.

[0053] FIG. 2 illustrates a vehicle frame 12 of a vehicle. The vehicle frame 12 may be adapted to form a structure of any vehicle and may vary in overall size and/or shape. However, for illustrative purposes, the vehicle frame 12 shown herein may be adapted for a bus (see FIG. 1).

[0054] The vehicle frame 12 may include a plurality of intersecting structural members 14. The structural members 14 may include pillars 16, horizontal members 18, crossmembers 20, or a combination thereof. As shown, the pillars 16, horizontal members 18, and crossmembers 20 may intersect at various joints 28 to form the overall vehicle frame 12. It is envisioned that a structural reinforcement 30 in accordance with the present teachings may be integrated or located within the joint 28 (or a region around or near the joint 28) to further reinforce the vehicle frame 12. However, it should be noted that the structural reinforcement 30 may be located anywhere along the vehicle frame 12 to reinforce one or more structural members 14.

[0055] FIG. 3 illustrates a close-up perspective view of a vehicle frame 12. As discussed above, the vehicle frame 12 may include a plurality of interconnected or joining structural members 14. For example, as shown in FIG. 3, a crossmember 20 may connect to a pillar 16 of the vehicle frame 12 within or along a joint 28. The joint 28 may be a connection point between the crossmember 20 and the pillar 16 or, similarly, a region in which the crossmember 20 and the pillar 16 abut each other or are positioned adjacent to each other.

[0056] Conventionally, joints 28 between structural members 14 may pose a relatively higher risk of deformation when compared to the remaining portions of the vehicle frame 12. That is, the joints 28 may form a localized point of weakness for the vehicle frame 12 due to welding or otherwise joining the structural members 14 to each other. As a result, joints 28 may conventionally be reinforced by incorporating additional reinforcing features, such as gussets, strengthening ribs, other fabricated reinforcements, or a combination thereof. Similarly, additional time and expense may be incurred due to ensuring welding or connection between the structural members 14 is done securely and free of certain defects that may promulgate fracturing the vehicle frame 12 along the joint 28.

[0057] To combat the aforementioned issues, FIG. 3 beneficially includes a structural reinforcement 30 located within one or more of the structural members 14 (see FIG. 4). Advantageously, without requiring excess manufacturing and/or fabrication time to incorporate secondary reinforcing features such as those mentioned above, the structural members 14 may be locally reinforced by the structural reinforcement 30. That is, the structural reinforcement 30 may be strategically positioned within or near the joint 28 to locally reinforcement the joint 28, which may otherwise typically be a point of weakness of the vehicle frame 12. To position the structural reinforcement 30, one or more stoppers 32 may but the structural reinforcement 30 and prevent the structural reinforcement 30 from extend or moving beyond a desired region. [0058] FTG. 4 illustrates cross-section 4-4 of FIG. 3. As discussed above, the structural members 14, such as the pillar 16 shown in FIG. 4, may be locally reinforced with a structural reinforcement 30. Beneficially, the structural reinforcement 30 may be positioned within a cavity 22 of the structural member 14 using one or more stoppers 32. The stoppers 32 may be located near one end or opposing ends of the structural reinforcement 30 to maintain a relative location of the structural reinforcement 30 within the structural member 14 and define a height (H) of the structural reinforcement 30. As a result, the stoppers 32 may prevent unwanted flow, creep, movement, or a combination thereof beyond a desired region (e.g., a joint). Thus, it is envisioned that, once inserted, the stoppers 32 may remain in place within the structural member 14 even after weight or force being applied to the stoppers 32 from the structural reinforcement 30.

[0059] Additionally, it is envisioned that the stoppers 32 may be selected from one or more materials, may vary in size and/or shape, may be inserted anywhere along the structural member 14 (e.g., through an end opening, through a cutout along a length of the structural member 14, etc.), or a combination thereof. For example, the stoppers 32 may be, but are not limited to, being made from one or more composite materials (e.g., polyurethane, polyamide, etc.), wool, a metallic material, other plastic materials, ceramics (e.g., ceramic wool), a foamed material, a felt material, or a combination thereof. Additionally, selection of a stopper 32 material may be dictated upon a composition of the structural reinforcement used in a given application.

[0060] Similarly, while materials may be selected, the structure of the stopper 32 may also vary depending on a given application. For example, the stopper 32 may be a substantially solid and/or compressible piece of material, may expand, may remain structurally rigid, or a combination thereof. For example, the stopper 32 may be inflatable (e.g., a balloon structure) that may be inserted through a small opening in the structural member 14 and then inflated beyond the size of the small opening to remain in place within the structural member 14.

[0061] Moreover, it is envisioned that the stoppers 32 may be inserted through existing openings within the structural member 14 (e.g., a terminal end opening of a tube), or may be inserted through a fabricated or existing hole along a length of the structural member 14. For example, the structural member 14 may include a first hole and a second adjacent hole along a length of the structural member 14 at a specified location for reinforcement. The first hole may be adapted to receive the stopper 32 so that the stopper 32 may be inserted into and secured in place within the structural member 14. That is, the stopper 32 may be compressed through a hole or otherwise contorted to reach an interior location of the structural member 14. Once inside the structural member 14, the stopper 32 may expand or otherwise be secured (e.g., adhered, fastened, etc.) in place. As a result, a structural reinforcement may then be injected through the adjacent second hole so that the structural reinforcement is prevented from flowing beyond the stopper 32. Thus, beneficially, a structural member 14 may be locally reinforced in a desired localized region. [0062] It should also be noted that, while the structural reinforcement 30 is illustrated as a localized reinforcement within the structural member 14, the structural reinforcement 30 may also extend beyond such a localized region (e.g., the joint 28) to reinforce further areas of the structural member 14. For example, it is contemplated that in certain applications the structural reinforcement 30 may reinforce all or substantially all of the structural member 14. However, beneficially, the structural reinforcement 30 may be locally applied to decrease overall weight of the structural member 14, decrease cost of the structural member 14, or both without compromising the structural integrity.

[0063] FIG. 5 illustrates a perspective view of a sectioned structural member 14. As discussed herein, the structural member 14 may vary in size and/or shape. Yet the structural reinforcement 30 may advantageously be incorporated into the various structural members 14. As shown, the structural member 14 may include opposing outer shell portions 24. The outer shell portions 24 may be joined together (e g., clamshell structure) to form a cavity 22 therein. A structural reinforcement 30 may then be injected into the cavity 22 through one or more apertures 26 located along the outer shell 24. As a result, the structural reinforcement 30 may beneficially reinforcement the structural member 14 free of secondary operations after injection of the structural reinforcement 30. Thus, secondary fastening or connection between structural members 14 may be eliminated without compromising the structural integrity of the structural members 14. [0064] Similarly, injection of the structural reinforcement 30 may not require additional secondary manufacturing steps to cure the structural reinforcement 30. It is envisioned that the structural reinforcement 30 may be a structural adhesive. The structural adhesive may foam, expand, or both after injection into the cavity 22 to partially or entirely fdl a region or entirety of the cavity 22. Beneficially, expansion, foaming, curing, or a combination thereof may take place at ambient temperature without requiring an activating agent or heightened temperature for final curing of the structural reinforcement 30. [0065] FTGS. 6A-6C illustrate various structural members 14. As shown, the structural members 14 may be a hollow tube having a cavity 22 therein. While square tubing is illustrated, the structural members 14 may have any desired shape, wall thickness, length, or a combination thereof. Similarly, the structural members 14 may have a cavity 22 along an entirety of their length or may include localized cavities 22 extending only a portion of the length of the structural members 14.

[0066] FIG. 6A illustrates a perspective view of a conventional structural member 14. As shown, the cavity 22 of the structural member 14 is hollow and free of any secondary material located therein. Such conventional structural members 14 may often be welded and reinforced during installation of the structural member 14 with a structure. That is, secondary operations may often be needed to add strengthening features along an exterior of the structural member 14.

[0067] FIG. 6B illustrates a perspective view of a structural member 14 similar to that shown in FIG. 6A. However, the cavity 22 of the structural member 14 is partially filled with a structural reinforcement 30. As shown, the structural reinforcement 30 may be a structural adhesive 30 injected into the cavity 22 of the structural member 14 and thereafter cured within the cavity 22 to reinforce the structural member 14.

[0068] Similarly, FIG. 6C illustrates a perspective view of a structural member 14 like that shown in FIG. 6B. However, the cavity 22 of the structural member 14 contains a greater volume of the structural reinforcement 30 when compared to that shown in FIG. 6B. As such, it may be gleaned from the present teachings that the structural reinforcement 30 may beneficially be tuned for specific material properties. For example, foam and/or expansion rate, density, stiffness, energy absorption, other material characteristics, or a combination thereof may be tuned to meet the requirements of various applications.

[0069] FIGS. 7A and 7B illustrate perspective views of a simulated rollover of a vehicle 10. As shown in FIG. 7A, the vehicle 10 includes a convention vehicle frame having one or more structural members free of structural reinforcement in accordance with the teachings herein. As illustrated, due to the lack of structural reinforcement, crumpling or deformation of the vehicle was beyond an acceptable amount based upon various testing requirements, as exemplified in the fail zone 34.

[0070] Conversely, the vehicle 10 shown in FIG. 7B includes a vehicle frame having structural members reinforced with the structural reinforcement as described herein. As shown, the vehicle maintained its shape during the rollover simulation and shows substantially less deformation when compared to that of the vehicle 10 in FIG. 7A. Thus, it may be gleaned that the structural reinforcement may also advantageously improve structural integrity of a vehicle 10 when compared to a convention vehicle structure.

[0071] While many of the aforementioned examples illustrate structural members in the context of a vehicle frame, it is envisioned that the present teachings may also provide a manner of reinforcing structural members in other applications.

[0072] For example, as shown in FIG. 12, an additional structural member 14 is utilized in an intrusion guard 36 of a vehicle 10. The intrusion guard 20 may be positioned substantially near a rear 44 of the vehicle 10. Similarly, as shown, the intrusion guard 20 may be mounted along an underbody of the vehicle 10 to protect unwanted vehicles or other objects from entering clearance between the bottom of the vehicle 10 and the ground. While the intrusion guard 36 is shown mounted near the rear 44 of the vehicle 10, it should be noted that a similar intrusion guard 36 may also be incorporated into the front and/or sides of the vehicle 10 for further protection.

[0073] As stated above, the intrusion guard 36 may include a structural member 14 extending substantially along a width of the vehicle and mounted beneath the vehicle 10 to prevent objects from entering beneath the vehicle 10. The structural member 14 may be secured to one or more uprights 38 of the intrusion guard 36 by attachment brackets 40 to maintain the position of the structural member 14. Similarly, the uprights 38 may then extend towards an underside or other portion of the vehicle 10 near the rear 44 so that the uprights 38 may be mounted to the vehicle 10 by one or more mounting brackets 42. Additionally, the mounting brackets 40 may be shared by one or more uprights 38 or each of the uprights 38 may include their own mounting bracket 40. For example, as shown, the mounting brackets 40 may each attach a pair of uprights 38 to the vehicle 10, thereby securing the structural member 14.

[0074] Advantageously, to further strengthen the impact resistance of the structural member 14 (and thus the overall intrusion guard 36), the structural member 14 may include a structural reinforcement (not shown) disposed therein (see FIG. 13). The structural reinforcement may be integrated into the structural member 14 in a manner such as those discussed above with respect to the vehicle frame. That is, the structural reinforcement may be injected into the structural member 30 and prevented from unwanted leakage by one or more stoppers 32 secured to and/or within openings of the structural member 14. As discussed above, the stoppers 32 may come in a variety of shapes and designs based upon the shape of the structural member 14 being reinforced. [0075] FIG. 13 illustrates cross-section 13 of the structural member 14 of FIG. 12. That is, the structural member 14 is part of a vehicle intrusion guard 36. As shown, the structural member 14 may include a cavity 22 extending at least a portion of the length of the structural member 14. Beneficially, the cavity 22 may be at least partially filled with a structural reinforcement 30. As discussed above, the structural reinforcement 30 may be tunable based upon a given application but may advantageously be injected into the cavity 22 and adhere, expand, or both upon activation once located in the cavity 22 of the structural member 13. As a result, the structural member 14 may be reinforced along an entire length or locally reinforced (e.g., near the uprights of the intrusion guard 36). Thus, the structural member 14 may be reinforced to increase impact force absorption yet may not significantly increase the overall weight of the structural member 14. As such, it may be seen from the present teachings that the structural reinforcement 30 may be implemented into a variety of applications to reinforce various structural members 30.

[0076] Illustrative Examples

[0077] A three-point bend test was completed on various samples (A, B, C) to determine performance of the structural reinforcement herein. Testing was completed based upon a force being applied to a supported sample. Sample A is a conventional square tube structural member free of a structural reinforcement, as shown in FIG. 6A. Sample B is a square tube member having a structural reinforcement therein at least partially fdling the cavity of the square tube, as shown in FIG. 6B. Moreover, Sample C is similar to that of Sample B, but with a greater volume of structural reinforcement injected into the cavity of the structural member, as shown in FIG. 6C. Additionally, it should be noted that samples A, B, and C each included a square tube having a diameter of about 15 mm. A summary of the samples and test results are shown in Table 1 below.

Table 1.

[0078] Additionally, as shown in corresponding FIG. 8, Sample C having the greater volume of structural reinforcement exhibited the greatest peak force strength at 26.73 KN. Surprisingly, Sample B exhibited almost identical peak force strength at 26.32 KN, even though a lesser volume of structural reinforcement was applied to the structural member. Similarly, both Samples B and C performed significantly better than a conventional square tube (Sample A), whereby the peak force strength was only 19.32 KN. As such, Samples B and C having a structural reinforcement were able to withstand a significantly higher peak force being applied during a three-point bending test before failure, as illustrated by a measure of extension shown in FIG. 8.

[0079] Based on the aforementioned results, the present teachings provide a solution that may surprisingly improve peak force and/or energy absorption performance by about 20% or more, by about 30% or more, or even by about 40% or more when compared to a conventional square tube (i.e., Sample A). Similarly, peak force and/or energy absorption performance when using the teachings herein may improve by about 70% or less, about 60% or less, or about 50% or less when compared to a conventional square tube (i.e., Sample A).

[0080] It should also be noted that such improvements as those listed above may depend at least in part on a profile and/or dimensions of the tubing be used. For example, the length, thickness, shape, or a combination thereof of the tube may impact performance improvement when incorporating the structural reinforcement herein. However, it is envisioned that, as stated above, peak force and/or energy absorption may be improved to some degree regardless of profile and/or dimensions of the tubing used. For example, depending on the profile and/or dimensions of the tube (e.g., square versus round tubing), peak force and/or energy absorption may be improved by about 20% to about 40%, though performance improvement is not limited to such a range.

[0081] Similarly, samples A-D below were tested and studied under quasistatic physical loading and also underwent simulated rollover. Samples A and B correlated a first vehicle frame joint, whereby Sample A was free of a structural reinforcement and Sample B included a structural reinforcement therein. Similarly, Samples C and D correlated to a second vehicle frame joint, whereby Sample C was free of a structural reinforcement and Sample D included a structural reinforcement therein. All samples were part of an overall vehicle frame as found in a bus and completed a rollover test as discussed above. Test results are shown below in Table 2.

Table 2.

[0082] As shown above, Samples B and D having a structural reinforcement within the structural member exhibited significantly better average peak loads when compared to the average peak loads of conventional joint samples.

[0083] Additionally, FIGS. 9A and 9B illustrated 3-point bending test results. FIG. 9A illustrates test results for 3-point bending of a conventional bare tube free of a structural reinforcement, illustrating both computer-aided engineering (CAE) modeling results and physical test results. Similarly, FIG. 9B illustrate test results for 3-point bending of a similar tube to that of FIG. 9A, but include a structural reinforcement therein, for both CAE modeling results and physical test results. As shown, physical and CAE test results significantly correlated for each sample, with the FIG. 9B showing surprisingly better results beyond CAE modelling (108.9% correlation). Furthermore, test results for the tubes having structural reinforcement exhibited a significantly higher peak force before failure, nearly doubling the overall strength of a conventional bare tub (FIG. 9A).

[0084] Furthermore, a set of seven (7) samples including a structural reinforcement therein were tested using a 3-point bend test and compared to baseline samples free of a structural reinforcement. Specifically, a sample was disposed across two supports spaced approximately 650 mm apart. A force was applied to an opposing side of the sample near or at a midpoint along a length of the sample. Table 3 below illustrates the configuration of Samples 1-7 along with baseline setups. More specifically, structurally reinforced samples 1 -7 were compared to conventional tube samples having different thicknesses, as shown below.

Table 3.

[0085] As shown above, Samples 1 and 2 correspond to a structurally reinforced tube having a thickness of about 2.0 mm, Samples 3 and 4 correspond to a structurally reinforced tube having a thickness of about 2.5 mm, Samples 5 and 6 correspond to a structurally reinforced tube having a thickness of about 2.9 mm, and Sample 7 corresponds to a structurally reinforced rectangular flat tube having a thickness of about 2.1 mm. The samples were then tested and compared to testing performance of conventional baseline tubes for each thickness above. The peak force and energy absorbed of each sample was recorded, as illustrated in Table 3 above. Similarly, FIGS. 10 and 11 visually illustrate an average peak force and an average energy absorption, respectively, for the structurally reinforced samples compared to the baseline samples.

[0086] As shown above and in FIGS. 10 and 11, compared to each baseline sample, the structurally reinforced samples provided a substantially improved performance for both peak force and energy absorption, with some samples showing an improvement of greater than about 30% or even 45% over the conventional baseline samples.

[0087] Additionally, a bend test was completed on multiple samples (Sample 1 and Sample 2) to determine performance of a structural reinforcement. Testing was conducted using the setup shown in FIG. 14. As shown, a structural member 14 of a vehicle 10 intrusion guard 36 was mounted to a mock portion of a vehicle 10 by an upright 38. The intrusion guard 36 may have a similar structure to that shown in FIG. 12. However, it is envisioned that for at least testing purposes, the upright 38 may be mounted directly to the vehicle 10 portion. [0088] Testing was completed based upon a force being applied in the direction (F) at specified point (Pl and P2) along the structural member 14 using an impactor 46. Sample l is a conventional structural member 14 of an intrusion guard 36 free of any structural reinforcement. Conversely, Sample 2 is a structural member 14 being reinforced by a structural reinforcement as described above. For Sample 1, a load of about 25 kN was applied at Pl and a displacement of the structural member 14 was recorded. Similarly, for Sample 2, Pl and P2 were tested with various applied loads to record the displacement thereof. A summary of the test results is shown in Table 4 below.

Table 4.

[0089] As shown above, Sample 2 having the structural reinforcement therein provided significantly less displacement at the achieved load applied. For example, Sample 2 at Pl was displaced nearly 50 mm less to that of Sample 1 (i.e., a conventional structural member 14). Thus, the structural reinforcement provided a significantly improved performance to that of a conventional member, to that point where failure may occur with the mounting bracket before the structural member 14 itself may fail.

[0090] Additionally, it should also be noted that conventional attempts to reinforce structural members 14 of an intrusion guard may often utilize additional sheet metal or backing plates. Conversely, by implementing the present teachings for structural reinforcement, a weight saving of greater than about 30% may be achieved. A summary of an example of such as case is shown in Table 5 below.

Table 5.

[0091] As shown above, Sample 2 corresponding to a structural member reinforced with the teachings herein provided an approximately 32% weight savings compared to a conventionally reinforced member (Sample 1).

[0092] Reference List

[0093] 10 Vehicle

[0094] 12 Vehicle Frame

[0095] 14 Structural Member

[0096] 16 Pillar

[0097] 18 Horizontal Member

[0098] 20 Crossmember

[0099] 22 Cavity of the Structural Member

[00100] 24 Outer Shell

[00101] 26 Aperture

[00102] 28 Joint

[00103] 30 Structural Reinforcement

[00104] 32 Stopper

[00105] 34 Fail Zone

[00106] 36 Intrusion Guard

[00107] 38 Upright

[00108] 40 Attachment Bracket

[00109] 42 Mounting Bracket [00110] 44 Rear of Vehicle [00111] 46 Impactor [00112] F Applied Force of the Impactor

[00113] H Height of the Structural Reinforcement

[00114] Unless stated otherwise, dimensions and geometries of the various structures depicted herein are not intended to be restrictive of the invention, and other dimensions or geometries are possible. Plural structural components can be provided by a single integrated structure. Alternatively, a single integrated structure might be divided into separate plural components. In addition, while a feature of the present invention may have been described in the context of only one of the illustrated embodiments, such feature may be combined with one or more other features of other embodiments, for any given application. It will also be appreciated from the above that the fabrication of the unique structures herein and the operation thereof also constitute methods in accordance with the present invention.

[00115] Unless otherwise stated, a teaching with the term “about” or “approximately” in combination with a numerical amount encompasses a teaching of the recited amount, as well as approximations of that recited amount. By way of example, a teaching of “about 100” encompasses a teaching of 100 +/- 15.

[00116] The preferred embodiment of the present invention has been disclosed. A person of ordinary skill in the art would realize however, that certain modifications would come within the teachings of this invention. Therefore, the following claims should be studied to determine the true scope and content of the invention.

[00117] The explanations and illustrations presented herein are intended to acquaint others skilled in the art with the invention, its principles, and its practical application. Those skilled in the art may adapt and apply the invention in its numerous forms, as may be best suited to the requirements of a particular use. Accordingly, the specific embodiments of the present invention as set forth are not intended as being exhaustive or limiting of the invention. The scope of the invention should, therefore, be determined not with reference to the above description, but should instead be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled. The disclosures of all articles and references, including patent applications and publications, are incorporated by reference in their entirety for all purposes. Other combinations are also possible as will be gleaned from the following claims, which are also hereby incorporated by reference in their entirety into this written description.