阅读说明：本技术 组合式复合金属能量吸收器 (Combined composite metal energy absorber ) 是由 R·杰尔杰伊 B·A·纽柯布 B·沙 于 2019-05-22 设计创作，主要内容包括：一种组合式复合金属能量吸收器,包括复合结构以及具有第一部分和第二部分的第一金属管,第一部分连结到复合结构。复合结构和第一金属管具有定制挤压曲线,以避免复合结构和第一金属管中任一个的过早压坏。(A modular composite metal energy absorber includes a composite structure and a first metal tube having a first portion and a second portion, the first portion being joined to the composite structure. The composite structure and the first metal tube have tailored crush curves to avoid premature crush of either of the composite structure and the first metal tube.)

1. A modular composite metal energy absorber, comprising:

a composite structure; and

a first metal tube having a first portion and a second portion, the first portion being joined to the composite structure,

wherein the composite structure and the first metal tube have tailored crush curves to avoid premature crush of either of the composite structure and the first metal tube.

2. The energy absorber of claim 1, wherein the first portion of the first metal structure is positioned within a portion of the composite structure.

3. The energy absorber of claim 1, further comprising a second metal tube, wherein the second metal tube is positioned over a second portion of the first metal tube.

4. The energy absorber of claim 1 wherein the initial and expansion force profiles of the first metal tube are such that crushing begins and crush expands along the first metal tube at a desired location in the first metal tube without prematurely beginning crush at other locations in the combined composite and metal energy absorber.

5. The energy absorber of claim 1 wherein the initial and expansion force profiles of the composite structure are such that crush begins and crush expands along the composite structure at a desired location in the composite structure without prematurely beginning crush at other locations in the combined composite and metallic energy absorber.

6. The energy absorber of claim 1 wherein said combined composite and metallic energy absorber extrusion force response curve is less than a force that prematurely extrudes said composite structure.

7. The energy absorber of claim 6 wherein the expansion force increases with position in the composite structure.

8. The energy absorber of claim 1 wherein the expansion force increases with position in the first metal structure.

9. The energy absorber of claim 1 wherein said combined composite and metal energy absorber has a crush force response curve that is less than a force that prematurely crushes said second metal tube.

10. The energy absorber of claim 1 wherein said first metal tube has interlocking features that engage said composite structure.

Disclosure of Invention

According to several aspects, a combined composite and metallic energy absorber includes a composite structure and a first metallic tube having a first portion and a second portion, the first portion being joined to the composite structure. The composite structure and the first metal tube have tailored crush curves to avoid premature crush of either of the composite structure and the first metal tube.

In another aspect of the invention, a first portion of a first metal structure is positioned within a portion of a composite structure.

In another aspect of the invention, the energy absorber further comprises a second metal tube, wherein the second metal tube is positioned over the second portion of the first metal tube.

In another aspect of the invention, the initial force profile and the expansion force profile of the first metal tube are such that crushing begins and crush expands along the first metal tube at a desired location in the first metal tube without prematurely beginning crush at other locations in the combined composite and metal energy absorber.

In another aspect of the invention, the initial force profile and the expansion force profile of the composite structure are such that crush begins and crush expands along the composite structure at a desired location in the composite structure without prematurely beginning crush at other locations in the combined composite and metallic energy absorber.

In another aspect of the invention, the crush force response curve of the combined composite and metallic energy absorber is less than the force that prematurely crushes the composite structure.

In another aspect of the invention, the expansion force increases with position in the composite structure.

In another aspect of the invention, the spreading force increases with position in the first metal structure.

In another aspect of the invention, the crush force response curve of the combined composite and metallic energy absorber is less than the force that prematurely crushes the second metal tube.

In another aspect of the invention, the first metal tube has an interlocking feature that engages the composite structure.

In another aspect of the invention, the interlocking feature is a helical thread feature.

In another aspect of the invention, the interlocking feature is a scalloped feature that enables controlled deformation at the end of the first metal tube.

In another aspect of the invention, the first metal tube has a controlled deformation region.

In another aspect of the invention, the interlocking feature is located on an outer surface of the first metal tube, and the first metal tube is positioned within the composite structure.

In another aspect of the invention, the interlocking feature is located on an interior surface of the first metal tube, and the first metal tube is positioned around the composite structure.

According to several aspects, an energy absorber includes a composite structure and a metal tube joined to the composite structure. The metal tube has an interlocking feature that engages the composite structure.

In another aspect of the invention, the composite structure and the metal tube have a tailored crush curve to avoid premature crush of either of the composite structure and the metal tube.

A method of generating a crush response curve for a combined composite and metallic energy absorber comprising: generating an initial force curve and an expansion force curve of the composite structure; generating an initial force curve and an expansion force curve of the first metal tube; and combining the initial force profile and the extension force profile of the composite structure and the first metal tube to produce a crush response curve for the combined composite and metal energy absorber.

In another aspect of the invention, the composite structure and the first metal tube have tailored crush curves to avoid premature crush of either of the composite structure and the first metal tube.

In another aspect of the invention, the method further comprises: generating an initial force curve and an expansion force curve of the second metal tube; and combining the second metal tube with the initial force profile and the extension force profile of the composite structure and the first metal tube to produce a crush response profile for the combined composite and metal energy absorber.

Further areas of applicability will become apparent from the description provided herein. It should be understood that the description and specific examples are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure.

Drawings

The drawings described herein are for illustration purposes only and are not intended to limit the scope of the present disclosure in any way.

FIG. 1A illustrates an example of a combined composite and metallic energy absorber according to principles of the present invention;

FIG. 1B illustrates a custom crush curve for the composite structure of the modular energy absorber shown in FIG. 1A;

FIGS. 2A-2D illustrate the effect of part geometry on the initiation and propagation forces on a part;

3A-3G illustrate a method for constructing a suggested crush force response curve for a combined composite and metallic energy absorber according to principles of the present invention;

FIG. 3H illustrates a proposed crush force response curve for a combined composite and metallic energy absorber in accordance with the principles of the present invention;

FIGS. 4A, 4B and 4C illustrate side cross-sectional views of three components of a combined composite and metallic energy absorber and their corresponding starting and expansion curves in accordance with the principles of the present invention;

FIGS. 5A and 5B illustrate proposed force displacement responses of the unitary energy absorber when the unitary energy absorber is crushed;

FIGS. 6A and 6B illustrate cross-sectional side views of a tubular connection for a composite-metal assembly according to principles of the present invention;

FIGS. 7A and 7B illustrate side cross-sectional views of alternative connections for composite-to-metal assemblies in accordance with the principles of the present invention;

FIGS. 8A and 8B illustrate side cross-sectional views of another alternative connection for a composite-metal assembly in accordance with the principles of the present invention;

FIG. 8C illustrates a side view of the composite-metal assembly shown in FIGS. 8A and 8B;

FIGS. 9A, 9B and 9C show end views of yet another alternative connection for a composite-metal assembly in accordance with the principles of the present invention;

FIGS. 10A and 10B illustrate side cross-sectional views of yet another alternative connection for a composite-metal assembly in accordance with the principles of the present invention;

11A and 11B show side cross-sectional views of yet another alternative connection for a composite-metal assembly in accordance with the principles of the present invention;

12A and 12B illustrate side cross-sectional views of yet another alternative connection for a composite-metal assembly in accordance with the principles of the present invention; and

fig. 13 illustrates a side cross-sectional view of yet another alternative connection for a composite-metal assembly in accordance with the principles of the present invention.

Detailed Description

The following description is merely exemplary in nature and is not intended to limit the present disclosure, application, or uses.

Referring to fig. 1A, 4B and 4C, cross-sectional views along the length of a combined composite and metal energy absorber 10 having a composite structure 11, a first metal tube 12 and a second metal tube 13 are shown. The first metal tube 12 serves as a metal joint joining the composite structure 11 and the second metal tube 13 together. Crush of the energy absorber 10 begins at the left side of the figure and expands in the direction shown by arrow N1.

The composite structure 11 has a first portion 14 and a second portion 15, while the first metal tube 12 has a tapered first portion 16 and a cylindrical portion 17. The tapered portion 16 mates with the interior of the first portion 14 of the composite structure 11. The second metal tube 13 has a generally cylindrical interior 18 that is positioned over the generally cylindrical portion 17 of the first metal tube 12.

The individual components 11, 12 and 13 of the combined composite and metallic energy absorber 10 have tailored crush curves (force versus displacement). An exemplary customized extrusion curve for composite structure 11 is shown in FIG. 1B. The characteristic features of the customized crush curve are an initial force N2 and an expansion force N3. At each location along the extruded length of a particular component, the initial and extension forces may be described. The initial force is the force required to begin crushing at that particular location along the length of the part. The expansion force is the force required to continue crushing the part as the extrusion continues from the extrusion initiation area through a particular location along the length of the part. In fig. 1A, 2A-2D, and 4A-4C, the expansion direction is from left to right, as indicated by arrow N1.

Both the initiation and expansion forces may be influenced by the geometry or material properties of the extruded structure. As an example, an extruded structure having a constant cross-section may have constant initial and expansion forces along the length of the structure, as shown in fig. 2A. Features on the ends of the crush feature can be incorporated to reduce the initiation force and control the location of the crush initiation, as shown in fig. 2B. The taper of the thickness may increase or decrease the initiation and expansion forces along the length of the extruded structure, as shown in fig. 2C and 2D. Note that in fig. 2A-2D and all subsequent figures, the initial force is represented by a dotted line and the expansion force is represented by a dashed line.

For each component in the combined composite and metallic energy absorber 10, the initial and extension force curves (force versus position along the length of the energy absorber or component) are plotted below each component in fig. 4A, 4B, and 4C. Specifically, the initial force 24 and the extension force 22 of the composite structure 11 illustrate an increase in force in the second portion 15 and a decrease in force in the first portion 14 along the length of the energy absorber. Similarly, the initial force 28 and the expansion force 26 of the first metal tube 12 are shown, and the initial force 32 and the expansion force 30 of the second metal tube 13 are shown. Line 20 represents the minimum initial force required at other locations along the length of the modular energy absorber 10 to avoid initiating crush at locations other than the desired location (here at the left end of the energy absorber). Furthermore, the crush force response of the unitized energy absorber 10 must not exceed the initial force at any location further along the length of the energy absorber in the crush expansion direction. Note that the initial and expansion forces of the individual components of the unitary energy absorber can be less than the crush force response of the unitary energy absorber, as shown by line 20 (the initial force of the unitary energy absorber) in fig. 4A-4C. However, compression of the modular energy absorber 10 in areas having such components must be a combined response of the multiple components to avoid premature crush of the energy absorber 10.

Assuming that the customized crush curves for components 11, 12, and 13 are cumulative, fig. 3A-3G illustrate steps for combining the initial and extension force curves for each component to produce a suggested crush force response curve for combined energy absorber 10 (fig. 3H). Again, the initial force is represented by the dotted line and the expansion force is represented by the dashed line; the compression force response curve is shown by the solid line. The combined or concatenated effects may also be incorporated into the method with appropriate characterization, but for simplicity these effects are not included here. The initial force of the modular energy absorber is the lowest value of the initial force curve. Crush will begin at this location along the length of the modular energy absorber. In this example, the extrusion is intended to start from the leftmost side. The combined energy absorber starting force N4 is taken from the leftmost end of the starting curve 24 of composite structure 11 (fig. 3A). After the crush begins, the recommended crush force response curve N6 in unitized energy absorber 10 continues through region R1 as shown by the expansion curve 22 of composite structure 11 (fig. 3B). When the extrusion reaches the overlapping region R2 of the composite structure 11 and the first metal structure 12, the extrusion starts in the tapered portion 16 of the first metal structure 12. Here, the proposed crush force response curve N7 for the unitized energy absorber 10 is the combination of the expansion curve 22 for the composite structure 11 and the start curve 28 for the first metal structure 12 (fig. 3C). After the beginning of the compression in the first metallic structure 12, it is proposed that the compression force response curve N8 continue in this overlap region R2 of the modular energy absorber 10 as a combination of the expansion curve 22 of the composite structure 11 and the expansion curve 26 of the first metallic structure 12 (fig. 3D).

When the extrusion reaches the end of the overlapping area of the composite structure 11 and the first metal structure 12, there is a transition to the overlapping area of the first metal structure 12 and the second metal structure 13. In the same way, the proposed crush force response curve N9 for the unitized energy absorber 10 is the combination of the expansion curve 26 for the first metal structure 12 and the start curve 32 for the second metal structure 13 (fig. 3E). In the overlap region R3 of the modular energy absorber 10, a pressing force response curve N10 is suggested that is the combination of the expansion curve 26 of the first metal structure 12 and the expansion curve 30 of the second metal structure 13 (fig. 3F). In the final region R4, the recommended pressing force response curve N11 is the expansion curve 30 of the second metal structure 13 (fig. 3G).

Turning to fig. 5A, a suggested crush force response curve 40 is shown that results when the energy absorber is crushed. At the transition between the regions R2 and R3, the size of the proposed curve exceeds the size of the starting curve 32 in the region R4. Thus, if crush of the modular energy absorber 10 continues to the transition, crush will begin in the second metal structure 13 in region R4. With the results of the above method, design decisions can be made to mitigate unnecessary crush. Two options for design variation are: (1) the crush length and therefore the design crush energy can be limited or (2) the second metal structure 13 can be redesigned to withstand higher crush forces.

By limiting the squeeze length N12, premature squeezing in region R4 may be avoided and a suggested actual squeeze force response curve may be estimated. Fig. 5B shows the actual crush force response curve 60 during crush of the energy absorber 10 with crush length limited to regions R1 and R2 (which also limits allowable crush energy).

Turning now to fig. 6A and 6B, an assembly 100 having a composite tube 102 and a metal tube 104 is shown. The composite tube 102 has an inner region 111 and an outer surface 108. The metal tube 104 has an interior surface 110 defining an interior region 112. A set of interlocking features, such as a set of teeth 106, are positioned on the interior surface 110. To join the composite tube 102 and the metal tube 104 together, one or both components are heated. The composite tube 102 is then inserted into the interior region 112 such that the set of teeth 106 forms a mechanically interlocking joint with the composite tube 102. Note that in other arrangements, the composite tube is an outer tube and the metal tube is an inner tube, with the interlocking features located on the outer surface of the metal tube.

Turning now to fig. 7A and 7B, an assembly 200 having a composite tube 102 and a metal tube 104 is shown. A set of interlocking features (e.g., threaded regions 206) are positioned on the interior surface 110. To join the composite tube 102 and the metal tube 104 together, the composite tube 102 is pressed and screwed into the inner metal tube 104, as indicated by arrow 208. Either or both of the composite and metal tubes may be heated prior to assembly of the structure 200. Note that in other arrangements, the composite tube is an outer tube and the metal tube is an inner tube, with the threads located on the outer surface of the metal tube.

Turning to fig. 8A, 8B, and 8C, an assembly 300 having a composite tube 102 and a metal tube 304 is shown. The metal tube 304 has an interior surface 310 that defines an interior region 312. A set of compliant scalloped features 314 is formed at one end of the metal tube 304. To join the composite tube 102 and the metal tube 304 together, the composite tube 102 is inserted into the metal tube 304 and pressure 320 is applied to the scalloped features 314 to plastically deform the features into the composite tube 102. In some arrangements, the pressure 320 is applied with a tool 324. In some arrangements, the tool 324 remains on the assembly 300.

Referring to fig. 9A, 9B and 9C, a portion of an assembly 400, a metal tube 404, is shown. Instead of the open sectors 314 previously described with respect to the metal tube 304, the metal tube 404 has a controlled deformation region 450 at the end of the tube, positioned between the wall portions 440 of the metal tube 404. After the composite tube 102 is inserted into the end of the metal tube 404, a pressure 560 is applied to the metal tube 404, deforming the deformed region 450, such that the metal tube 404 is joined with the composite tube 102. Note that in some arrangements, the metal tube 404 and the metal tube 304 incorporate mechanical interlocking features 660 to engage the composite tube 102.

Turning to fig. 10A and 10B, an assembly 700 having a composite pipe 702 and a metal pipe 704 is shown. The composite tube 702 has an interior region 711 and an exterior surface 708. The composite tube has flares in the tube or steps 712, 714 at the ends of the tube 702 in some arrangements. The metal tube 104 has an interior region 712 and a set of interlocking features 716 on its exterior surface, such as, for example, a set of teeth. To join the composite tube 702 and the metal tube 704 together, one or both components are heated. The stepped regions 712, 714 of the composite tube 702 are then pushed onto the interlocking features 716. Pressure 720 is applied to the stepped regions 712, 714 such that the interlocking features 716 form a joint with the stepped regions 712, 714.

Turning now to fig. 11A and 11B, an assembly 800 is shown having a composite tube 802 and a metal tube 806 joined together by a tapered interface joint 804 made of a metallic material or a composite material. Composite tube 802 has an outer surface 812 and an inner region 808 with a tapered inner surface 810. The metal tube 806 has an exterior surface 820 and an interior surface 822 defining an interior region 824. The interface fitting 804 has an exterior surface 814 and an interior surface 818 defining an interior region 816. To join the composite tube 802 and the metal tube 806 together, the interface joint 804 is placed in the composite tube 802 to form an interference fit, as shown in fig. 11B, while the interface joint 804 and the metal tube 806 in some arrangements form a metal-to-metal joint that may be joined together, for example, with self-tapping threads.

Referring to fig. 12A and 12B, another assembly 900 is shown with a composite tube 802, an interface joint 804, and a metal tube 806. In this arrangement, the interface fitting 804 is again placed in the composite tube 802 to form an interference fit between the interface fitting 804 and the composite tube 802. The ends of the interface joint 804 are then formed or flared to form stepped regions 830, 832, as shown on the right hand side of fig. 12A. The metal tube 806 is then inserted into the flared regions 830, 832 to join the metal tube 806 to the composite tube 802.

Turning now to fig. 13, an assembly 900 is shown having a composite pipe 902 and a metal pipe 904. Composite tube 902 has an interior region 908 defined by interior surface 906. The metal tube 904 has an interior region 912 and an exterior surface 910 with a set of interlocking features, such as a set of teeth 914. To join composite tube 902 and metal tube 904 together, one or both components are heated. The set of interlocking features 914 is then inserted into composite tube 902 such that the set of interlocking features 914 forms a mechanical interlocking joint with composite tube 902. The assembly 900 also includes a load bearing and position limiting feature 916.

In any of the assemblies previously described, the composite tube utilizes chopped or continuous fibers in a polymer matrix in various arrangements. Suitable matrix materials include thermoplastics and thermosets. The fibrous material includes carbon fibers, glass fibers, basalt fibers, para-aramid fibers, meta-aramid fibers, polyethylene fibers, and any combination thereof. The reinforcement material may be formed into woven fabrics, continuous random fabrics, discontinuous random fibers, chopped random fabrics, continuous strand unidirectional layers, oriented chopped strand layers, braided fabrics, and any combination thereof.