Vessel and method for protecting a pressure vessel

Abstract

The vessel includes first and second hollow shells including first and second inner surfaces, respectively, for receiving a portion of a pressure vessel (PV). The first hollow shell includes a fibrous layer at least partially impregnated with a resin and an energy dissipative material substantially concentric with the first inner surface and disposed between the first inner surface and the fibrous layer. The second hollow shell includes a fibrous layer at least partially impregnated with a resin and an energy dissipative material substantially concentric with the second inner surface and disposed between the second inner surface and the second fibrous layer. The first and second hollow shells are attachable to one another to define a volume for at least partially enclosing the PV.

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the benefit of U.S. Provisional Patent Application No. 63 / 195,295, entitled "Containers and Methods for Protecting Pressure Vessels," filed June 1, 2021, the entire contents of which are incorporated herein by reference.

[0002] Field This application relates to pressure vessels. [Background technology]

[0003] background A pressure vessel (PV) is a reservoir configured to store a fluid, such as a liquid or gas, under pressure. The pressure can be substantially higher than ambient pressure, for example, exceeding 200 bar. The fluid within a PV can be dangerous alone or when under pressure. For example, some PVs can be used to store hydrogen at a pressure of approximately 700 bar. While it may be desirable to use pressurized hydrogen or other pressurized fuels as a fuel source, PVs used in vehicles (such as automobiles, trucks, airplanes, and spacecraft) can be subject to sudden motion, such as that caused by a crash or sudden stop. If a PV is damaged, the resulting leak or explosion can be dangerous or even catastrophic. Therefore, improved methods of protecting PVs are needed. Summary of the Invention [Means for solving the problem]

[0004] overview Provided herein are vessels and methods for protecting pressure vessels.

[0005] In one aspect, a container for a pressure vessel is provided herein. The container may include a first hollow shell including a first inner surface configured to receive a first portion of the pressure vessel. The container may include a second hollow shell including a second inner surface configured to receive a second portion of the pressure vessel. The first hollow shell may be substantially concentric with the first inner surface and include a first fiber layer at least partially impregnated with a resin. The first hollow shell may be substantially concentric with the first inner surface and include a first energy dissipating material disposed between the first inner surface and the first fiber layer. The second hollow shell may be substantially concentric with the second inner surface and include a second fiber layer at least partially impregnated with a resin. The second hollow shell may be substantially concentric with the second inner surface and include a second energy dissipating material disposed between the second inner surface and the second fiber layer. The first and second hollow shells may be attachable to each other to define a volume for at least partially enclosing the pressure vessel.

[0006] In some examples, at least one of the first and second interior surfaces is at least partially cylindrical, at least partially spherical, or at least partially conical.

[0007] Additionally or alternatively, in some cases, at least one of the first and second interior surfaces is at least partially axisymmetric.

[0008] Additionally or alternatively, in some cases, the first and second hollow shells define a volume for substantially enclosing the pressure vessel.

[0009] Additionally or alternatively, in some cases, the first hollow shell defines a first half-cylinder and the second hollow shell defines a second half-cylinder.

[0010] Additionally or alternatively, in some examples, the first hollow shell defines a first bowl shape and the second hollow shell defines a second bowl shape.

[0011] Additionally or alternatively, in some examples, at least one of the first and second fibrous layers comprises a plurality of spiral plies.

[0012] In some examples, the helical plies may be arranged helically relative to one another. Optionally, the first one of the helical plies (i=1) may be arranged at an angle θ with respect to the axis. i=1 Optionally, a second one of the spiral plies (i=2) may have an angle of θ with respect to the axis. i=2 Optionally, the tows may be wound adjacent to one another at an angle of θ i=2 is θ i=1 and varies from about 1 to about 25 degrees.

[0013] In some examples, the spiral plies comprise interwoven tows. Optionally, the first of the spiral plies (i=1) is at an angle (+α i=1 +θ i=1 ) and (-α i=1 +θ i=1 ) tows. Optionally, the second one of the spiral plies (i=2) has an angle of (+α i=2 +θ i=2 ) and (-α i=2 +θ i=2 ) and optionally, i=2 is θ i=1 and varies from about 1 to about 25 degrees.

[0014] Additionally or alternatively, in some examples, the first energy dissipative material defines an interior surface of the first hollow shell.

[0015] Additionally or alternatively, in some cases, the first fibrous layer defines an exterior surface of the first hollow shell.

[0016] Additionally or alternatively, in some examples, a second energy dissipative material defines the interior surface of the second hollow shell.

[0017] Additionally or alternatively, in some cases, the second fibrous layer defines an exterior surface of the second hollow shell.

[0018] Additionally or alternatively, in some examples, the first hollow shell further comprises a third fibrous layer substantially concentric with the first inner surface, and a third energy dissipating material substantially concentric with the first inner surface and disposed between the first fibrous layer and the third fibrous layer.

[0019] Additionally or alternatively, in some examples, the second hollow shell further comprises a fourth fibrous layer substantially concentric with the second inner surface, and a fourth energy dissipating material substantially concentric with the second inner surface and disposed between the second fibrous layer and the fourth fibrous layer.

[0020] Additionally or alternatively, in some examples, the first hollow shell comprises a first spirally braided layer or woven fabric disposed between the first inner surface and the first textile layer.

[0021] Additionally or alternatively, in some examples, the second hollow shell includes a second spirally braided layer or woven fabric disposed between the second inner surface and the second fibrous layer, and optionally, the resin of the first fibrous layer at least partially impregnates the first spirally braided layer or woven fabric, or the resin of the second fibrous layer at least partially impregnates the second spirally braided layer or woven fabric.

[0022] Additionally or alternatively, in some examples, the fibers of the first and second fibrous layers independently comprise at least one material selected from the group consisting of ultra-high molecular weight polyethylene (UHMWPE), para-aramid, carbon, graphite, glass, aramid, basalt, ultra-high molecular weight polypropylene (UHMWPP), natural materials, metals, quartz, ceramics, and recycled fibers.

[0023] Additionally or alternatively, in some examples, at least one of the first and second energy dissipative materials comprises a foam, optionally including polyvinyl chloride (PVC), expandable polyurethane (PU), expanded polystyrene (EPS), expanded polypropylene (EPP), polyethylene (PE), aluminum foam, radially oriented scaffold 3D printing material, honeycomb structure, closed cell, open cell, viscoelastic gel, or defining a metamaterial.

[0024] Additionally or alternatively, in some cases, the first fibrous layer comprises substantially the same composition as the second fibrous layer.

[0025] Additionally or alternatively, in some cases, the first fibrous layer comprises a different composition than the second fibrous layer.

[0026] Additionally or alternatively, in some cases, the first fibrous layer comprises substantially the same material composition as the second fibrous layer.

[0027] Additionally or alternatively, in some cases, the first fibrous layer comprises a different material composition than the second fibrous layer.

[0028] Additionally or alternatively, in some cases, the first energy dissipative material comprises substantially the same composition as the second energy dissipative material.

[0029] Additionally or alternatively, in some cases, the first energy dissipative material comprises a different composition than the second energy dissipative material.

[0030] Additionally or alternatively, in some cases, the first energy dissipative material comprises substantially the same material composition as the second energy dissipative material.

[0031] Additionally or alternatively, in some examples, the first energy dissipative material comprises a different material composition than the second energy dissipative material.

[0032] Additionally or alternatively, in some examples, the container further comprises a first fastener attached to the first hollow shell and a second fastener attached to the second hollow shell and configured to engage with the first fastener to attach the first hollow shell to the second hollow shell. Optionally, the first fastener comprises a first thread, and the second fastener comprises a second thread configured to rotatably engage with the first thread. Optionally, the first fastener comprises a toggle latch, a pipe clamp, or a bolted joint.

[0033] Additionally or alternatively, any of the containers provided herein may include a sensor embedded in or between one or more layers of the container. Optionally, the sensor includes a piezoelectric sensor configured to monitor for impacts. Optionally, the sensor includes a fiber Bragg grating (FBG) configured to monitor for gas leaks.

[0034] In another aspect, provided herein is a method of protecting a pressure vessel. The pressure vessel may have a first and a second portion. The method may include inserting the first portion of the pressure vessel into a first hollow shell of any of the vessels provided herein. The method may include inserting the second portion of the pressure vessel into a second hollow shell of any of the vessels provided herein. The method may include attaching the first hollow shell to the second hollow shell.

[0035] In another aspect, provided herein is another method of protecting a pressure vessel. The method can include covering the pressure vessel with a plurality of helical plies. The helical plies can be arranged helically relative to one another.

[0036] In some cases, the first one of the spiral plies (i=1) is oriented θ i=1 Optionally, a second one of the spiral plies (i=2) may have an angle of θ with respect to the axis. i=2 Optionally, the tows may be wound adjacent to one another at an angle of θi=2 is θ i=1 and varies from about 1 to about 25 degrees.

[0037] Additionally or alternatively, in some cases, the spiral plies comprise interwoven tows. Optionally, the first of the spiral plies (i=1) is (+α i=1 +θ i=1 ) and (-α i=1 +θ i=1 ) tows. Optionally, the second one of the spiral plies (i=2) has an angle of (+α i=2 +θ i=2 ) and (-α i=2 +θ i=2 ) and optionally, i=2 is θ i=1 and varies from about 1 to about 25 degrees.

[0038] In yet another aspect provided herein, a method of manufacturing a container for a pressure vessel is provided. The method may include forming a first hollow shell and forming a second hollow shell. The first hollow shell may be formed using steps including molding a first energy dissipating material to form a first inner surface configured to receive a first portion of the pressure vessel and forming a first fibrous layer, at least partially impregnated with resin, on the first energy dissipating material so as to be substantially concentric with the first energy dissipating material. The second hollow shell may be formed using steps including molding a second energy dissipating material to form a second inner surface configured to receive a second portion of the pressure vessel and forming a second fibrous layer, at least partially impregnated with resin, on the second energy dissipating material so as to be substantially concentric with the second energy dissipating material. The first hollow shell is attachable to the second hollow shell to at least partially surround the pressure vessel.

[0039] In yet another aspect provided herein, a pressure vessel is provided. The pressure vessel can include a plurality of helical plies. The helical plies can be helically arranged relative to one another.

[0040] In some cases, the first one of the spiral plies (i=1) is oriented θ i=1 Optionally, a second one of the spiral plies (i=2) may have an angle of θ with respect to the axis. i=2 Optionally, the tows may be wound adjacent to one another at an angle of θ i=2 is θ i=1 and varies from about 1 to about 25 degrees.

[0041] In some examples, the spiral plies comprise interwoven tows. Optionally, the first of the spiral plies (i=1) is at an angle (+α i=1 +θ i=1 ) and (-α i=1 +θ i=1 ) tows. Optionally, the second one of the spiral plies (i=2) has an angle of (+α i=2 +θ i=2 ) and (-α i=2 +θ i=2 ) and optionally, i=2 is θ i=1 and varies from about 1 to about 25 degrees. In an embodiment of the present invention, for example, the following items are provided: (Item 1) A container for a pressure vessel, a first hollow shell including a first inner surface configured to receive a first portion of the pressure vessel; a first fibrous layer substantially concentric with the first inner surface and at least partially impregnated with a resin; a first energy dissipative material substantially concentric with the first inner surface and disposed between the first inner surface and the first fiber layer; a first hollow shell comprising: a second hollow shell including a second inner surface configured to receive a second portion of the pressure vessel; a second fibrous layer substantially concentric with the second inner surface and at least partially impregnated with a resin; a second energy dissipative material substantially concentric with the second inner surface and disposed between the second inner surface and the second fiber layer; a second hollow shell comprising: Equipped with The vessel, wherein the first and second hollow shells are attachable to one another to define a volume for at least partially enclosing the pressure vessel. (Item 2) Item 10. The container of item 1, wherein at least one of the first and second inner surfaces is at least partially cylindrical, at least partially spherical, or at least partially conical. (Item 3) 3. The container of claim 1, wherein at least one of the first and second inner surfaces is at least partially axisymmetric. (Item 4) 4. The vessel of any one of claims 1 to 3, wherein the first and second hollow shells define a volume for substantially enclosing the pressure vessel. (Item 5) 5. The container of any one of items 1 to 4, wherein the first hollow shell defines a first half-cylinder and the second hollow shell defines a second half-cylinder. (Item 6) 6. The container of any one of items 1 to 5, wherein the first hollow shell defines a first bowl shape and the second hollow shell defines a second bowl shape. (Item 7) 7. The container of any one of the preceding claims, wherein at least one of the first and second fibrous layers comprises a plurality of spiral plies. (Item 8) 8. The container of claim 7, wherein the spiral plies are arranged spirally relative to each other. (Item 9) The first helical ply (i=1) of the helical plies is oriented at an angle θ i=1 Item 9. The container of item 8, comprising a plurality of tows wound adjacent to each other at an angle of . (Item 10) The second helical ply (i=2) of the helical plies is oriented at an angle θ i=2 10. The container of claim 8 or 9, comprising a plurality of tows wound adjacent to each other at an angle of . (Item 11) θ i=2 is θ i=1 11. The container according to item 10, wherein the temperature is about 1 to about 25 degrees different from the temperature of the container. (Item 12) Item 9. The container of item 8, wherein the spiral ply comprises interwoven tows. (Item 13) The first spiral ply (i=1) of the spiral plies is (+α i=1 +θ i=1 ) and (-α i=1 +θ i=1 Item 13. The container of item 12, comprising tows interwoven at an angle of 0.5°. (Item 14) The second spiral ply (i=2) of the spiral plies is (+α i=2 +θ i=2 ) and (-α i=2 +θ i=2 14. The container of claim 12 or 13, comprising tows interwoven at an angle of 0.5°. (Item 15) θ i=2 is θ i=1 15. The container according to item 14, wherein the temperature is from about 1 to about 25 degrees Celsius. (Item 16) 16. The container of any one of the preceding claims, wherein the first energy dissipative material defines the interior surface of the first hollow shell. (Item 17) 17. The container of any one of the preceding claims, wherein the first fibrous layer defines an outer surface of the first hollow shell. (Item 18) 18. The container of any one of the preceding claims, wherein the second energy dissipative material defines the inner surface of the second hollow shell. (Item 19) 19. The container of any one of the preceding claims, wherein the second fibrous layer defines an outer surface of the second hollow shell. (Item 20) The first hollow shell is a third fibrous layer substantially concentric with the first inner surface; a third energy dissipative material substantially concentric with the first inner surface and disposed between the first and third fiber layers; and 20. The container of any one of items 1 to 19, further comprising: (Item 21) The second hollow shell is a fourth fibrous layer substantially concentric with the second inner surface; and a fourth energy dissipative material substantially concentric with the second inner surface and disposed between the second fiber layer and the fourth fiber layer; 21. The container of any one of items 1 to 20, further comprising: (Item 22) 22. The container of any one of the preceding claims, wherein the first hollow shell comprises a first spirally braided layer or woven fabric disposed between the first inner surface and the first fiber layer. (Item 23) 23. The container of any one of the preceding claims, wherein the second hollow shell comprises a second spirally braided layer or woven fabric disposed between the second inner surface and the second fiber layer. (Item 24) 24. The container of claim 23, wherein the resin of the first fibrous layer at least partially impregnates the first spirally braided layer or woven fabric, or the resin of the second fibrous layer at least partially impregnates the second spirally braided layer or woven fabric. (Item 25) 25. The container of any one of the preceding claims, wherein the fibers of the first and second fibrous layers independently comprise at least one material selected from the group consisting of ultra-high molecular weight polyethylene (UHMWPE), para-aramid, carbon, graphite, glass, aramid, basalt, ultra-high molecular weight polypropylene (UHMWPP), natural materials, metals, quartz, ceramics, and recycled fibers. (Item 26) 26. The container of any one of the preceding claims, wherein at least one of the first and second energy dissipative materials comprises foam. (Item 27) 27. The container of item 26, wherein the foam comprises polyvinyl chloride (PVC), expandable polyurethane (PU), expanded polystyrene (EPS), expanded polypropylene (EPP), polyethylene (PE), aluminum foam, radially oriented scaffold 3D printing material, honeycomb structure, closed cell, open cell, viscoelastic gel, or defines a metamaterial. (Item 28) 28. The container of any one of the preceding claims, wherein the first fibrous layer comprises substantially the same composition as the second fibrous layer. (Item 29) 28. The container of any one of the preceding items, wherein the first fibrous layer comprises a different composition than the second fibrous layer. (Item 30) 30. The container of any one of the preceding claims, wherein the first fibrous layer comprises substantially the same material composition as the second fibrous layer. (Item 31) 30. The container of any one of the preceding claims, wherein the first fibrous layer comprises a different material composition than the second fibrous layer. (Item 32) 32. The container of any one of the preceding claims, wherein the first energy dissipative material comprises substantially the same composition as the second energy dissipative material. (Item 33) 32. The container of any one of the preceding claims, wherein the first energy dissipative material comprises a different composition than the second energy dissipative material. (Item 34) 33. The container of any one of the preceding claims, wherein the first energy dissipative material comprises substantially the same material composition as the second energy dissipative material. (Item 35) 33. The container of any one of the preceding claims, wherein the first energy dissipative material comprises a different material composition than the second energy dissipative material. (Item 36) a first fastener attached to the first hollow shell; a second fastener attached to the second hollow shell and configured to engage with the first fastener to attach the first hollow shell to the second hollow shell; 36. The container of any one of items 1 to 35, further comprising: (Item 37) Item 37. The container of item 36, wherein the first fastener comprises a first thread and the second fastener comprises a second thread configured to rotatably engage the first thread. (Item 38) Item 37. The container of item 36, wherein the first fastener comprises a toggle latch, a pipe clamp, or a bolted joint. (Item 39) 1. A method of protecting a pressure vessel having a first portion and a second portion, comprising: inserting the first part of the pressure vessel into a first hollow shell of a vessel according to any one of items 1 to 38; inserting the second part of the pressure vessel into a second hollow shell of a vessel according to any one of items 1 to 38; attaching the first hollow shell to the second hollow shell; A method comprising: (Item 40) 1. A method for protecting a pressure vessel, comprising: covering said pressure vessel with a plurality of spiral plies; wherein the helical plies are arranged helically relative to one another. (Item 41) The first helical ply (i=1) of the helical plies is oriented at an angle θ i=1 Item 41. The method of item 40, comprising a plurality of tows wound adjacent to each other at an angle of . (Item 42) The second helical ply (i=2) of the helical plies is oriented at an angle θ i=2 Item 42. The method of claim 41, wherein the tows are wound adjacent to each other at an angle of . (Item 43) θ i=2 is θi=1 43. The method of claim 42, wherein the temperature is about 1 to about 25 degrees different from the above. (Item 44) 45. The method of any one of items 40 to 44, wherein the spiral ply comprises interwoven tows. (Item 45) The first spiral ply (i=1) of the spiral plies is (+α i=1 +θ i=1 ) and (-α i=1 +θ i=1 Item 45. The method of claim 44, wherein the tows are interwoven at an angle of 0.5°. (Item 46) The second spiral ply (i=2) of the spiral plies is (+α i=2 +θ i=2 ) and (-α i=2 +θ i=2 Item 46. The method of claim 45, wherein the tows are interwoven at an angle of 0.5°. (Item 47) θ i=2 is θ i=1 47. The method of claim 46, wherein the temperature is about 1 to about 25 degrees different from the temperature of the substrate. (Item 48) 1. A method of manufacturing a container for a pressure vessel, comprising: A first hollow shell molding a first energy dissipative material to form a first interior surface configured to receive a first portion of the pressure vessel; and forming a first fibrous layer at least partially impregnated with resin over the first energy dissipative material so as to be substantially concentric with the first energy dissipative material; forming the material using steps including: A second hollow shell molding a second energy dissipative material to form a second interior surface configured to receive a second portion of the pressure vessel; and forming a second fibrous layer at least partially impregnated with resin over the second energy dissipative material so as to be substantially concentric with the second energy dissipative material; forming the material using steps including: Including, the first hollow shell is attachable to the second hollow shell to at least partially enclose the pressure vessel; method. (Item 49) 1. A pressure vessel, comprising: 1. A pressure vessel comprising a plurality of helical plies, the helical plies being helically disposed relative to one another. (Item 50) The first helical ply (i=1) of the helical plies is oriented at an angle θ i=1 50. The method of claim 49, wherein the tows are wound adjacent to each other at an angle of . (Item 51) The second helical ply (i=2) of the helical plies is oriented at an angle θ i=2 Item 51. The method of item 50, comprising a plurality of tows wound adjacent to each other at an angle of . (Item 52) θ i=2 is θ i=1 52. The method of claim 51, wherein the temperature is about 1 to about 25 degrees different from the above. (Item 53) 53. The method of any one of items 49 to 52, wherein the spiral ply comprises interwoven tows. (Item 54) The first spiral ply (i=1) of the spiral plies is (+α i=1 +θ i=1 ) and (-α i=1 +θ i=1 Item 54. The method of claim 53, wherein the tows are interwoven at an angle of 0.5°. (Item 55) The second spiral ply (i=2) of the spiral plies is (+α i=2 +θ i=2 ) and (-α i=2 +θ i=2 55. The method of claim 54, wherein the tows are interwoven at an angle of 0.5°. (Item 56) θ i=2 is θ i=1 56. The method of claim 55, wherein the temperature is about 1 to about 25 degrees different from the temperature of the substrate. (Item 57) 39. The container of any one of the preceding items, further comprising a sensor embedded in or between one or more layers of the container. (Item 58) Item 58. The container of item 57, wherein the sensor comprises a piezoelectric sensor configured to monitor for impacts. (Item 59) 59. The container of claim 57 or 58, wherein the sensor comprises a fiber Bragg grating (FBG) configured to monitor for gas leaks. [Brief explanation of the drawings]

[0042] [Figure 1] 1A-1B show schematic cross-sectional views of an exemplary vessel for a pressure vessel (PV).

[0043] [Figure 2]2A-2B schematically illustrate cross-sectional views of an exemplary enclosure assembly around a PV.

[0044] [Figure 3AB] 3A-3C show schematic diagrams of exemplary configurations of different plies. [Figure 3C] 3A-3C show schematic diagrams of exemplary configurations of different plies.

[0045] [Figure 4] 4A-4B schematically illustrate cross-sectional views of another exemplary enclosure for a PV.

[0046] [Figure 5] FIG. 5 shows a schematic cross-sectional view of another exemplary enclosure for a PV.

[0047] [Figure 6] FIG. 6 shows a schematic cross-sectional view of another exemplary enclosure for a PV.

[0048] [Figure 7] FIG. 7 shows a schematic diagram of an exemplary overlap for a PV.

[0049] [Figure 8] FIG. 8 shows a schematic diagram of an exemplary structure of a PV.

[0050] [Figure 9] 9-12 show exemplary flows of operations in respective methods for making a container for a PV. [Figure 10] 9-12 show exemplary flows of operations in respective methods for making a container for a PV. [Figure 11] 9-12 show exemplary flows of operations in respective methods for making a container for a PV. [Figure 12]9-12 show exemplary flows of operations in respective methods for making a container for a PV.

[0051] [Figure 13] FIG. 13 shows an exemplary flow of operations in a method for making a PV.

[0052] [Figure 14A] FIG. 14A shows a schematic model of crack propagation through an exemplary spiral layup.

[0053] [Figure 14B] FIG. 14B is a plot of energy release rate as a function of depth for different pitch angles in the model of FIG. 14A. DETAILED DESCRIPTION OF THE INVENTION

[0054] Detailed Description Provided herein are vessels and methods for protecting pressure vessels.

[0055] As provided herein, PVs (such as hydrogen pressure vessels, HPVs, etc.) can be protected by partially or completely enclosing them in a crash-resistant container, sometimes referred to as a protective box or crash box. The use of such a separate container can separate the pressure-resistance function of the PV from the crashworthiness / crashworthiness of the container. For example, such a container can inhibit damage to the PV from impacts such as a collision or external projectile. Because the container is separate from and encloses the PV, the structural designs of the container and PV can be individually optimized, for example, through different selections of fiber type, resin, and manufacturing process. In some examples herein, the container can be designed as a laminated structure including at least one outer fiber composite shell (e.g., a spiral composite shell) and at least one energy dissipating material, sometimes referred to as a "core." The container may be formed into two or more parts to accommodate insertion of the PV, and the parts may be attachable to each other to partially or completely enclose the PV therein, thereby protecting the PV. Thus, if the container is damaged, it can be easily replaced with another such container without having to replace the PV, which can be cumbersome, expensive, and dangerous. In some examples herein, a damaged vessel may be repaired and then reused with the same or a different PV. In other examples herein, the PV itself may be covered by multiple helical plies arranged helically relative to one another, or the PV may be formed using multiple helical plies arranged helically relative to one another.

[0056] 1A-1B schematically illustrate cross-sectional views of an exemplary container 110 for a PV 100. The container 110 at least partially surrounds the PV 100, and in some examples, substantially surrounds or completely surrounds the PV 100. As used herein, "at least partially surrounds" the PV is intended to mean that at least a portion of the PV is surrounded by the container. "Substantially surrounds" the PV is intended to mean that a majority of the PV (e.g., more than 50%, more than 60%, more than 70%, more than 80%, more than 90%, more than 95%, more than 98%, or up to 99% of the PV) is surrounded by the container, while the remainder of the PV (e.g., 1% or more) is not surrounded by the container. In the illustrated example, the neck 101 of the PV 100 may protrude from the container 110 so that fluid within the PV may be used, while the remainder of the PV may be enclosed within the container 110. In this example, the main reservoir of the PV 100 is completely enclosed within the container 110, but another portion of the PV 100 (here, which may be the neck 101, or only a portion of the neck) protrudes from the container, so that the PV 100 can be considered to be substantially enclosed within the container 110. "Completely enclosing" a PV is intended to mean that the entire PV is surrounded by the container.

[0057] The vessel 110 may include a first hollow shell 120 and a second hollow shell 130. The first hollow shell 120 may include a first inner surface 121 configured to receive a first portion of the pressure vessel 100. The first hollow shell 120 may include a first fiber layer 122 substantially concentric with the first inner surface and at least partially impregnated with a resin. The first hollow shell 120 may also include a first energy dissipating material 123 substantially concentric with the first inner surface 121 and disposed between the first inner surface 121 and the first fiber layer 122. The second hollow shell 130 may include a second inner surface 131 configured to receive a second portion of the pressure vessel 100. The second hollow shell 130 may include a second fiber layer 132 substantially concentric with the second inner surface 131 and at least partially impregnated with a resin. The second hollow shell 130 may also include a second energy dissipating material 133 substantially concentric with the second inner surface and disposed between the second inner surface and the second fiber layer. The first and second hollow shells 120, 130 may be attachable to one another to define a volume for at least partially enclosing the pressure vessel 100. In the non-limiting example shown in FIG. 1A, the first and second hollow shells 120, 130 meet at a junction 140. Exemplary structures for attaching the hollow shells to one another are described with reference to FIGS. 2A-2B. It should be understood that the use of labels such as "first," "second," etc. to refer to elements is not intended to imply a particular spatial relationship between those elements.

[0058] In the non-limiting example shown in FIGS. 1A-1B, the first energy dissipating material 123 may define the inner surface 121 of the first hollow shell 120, and the first fiber layer 122 may define the outer surface of the first hollow shell. Similarly, the second energy dissipating material 133 may define the inner surface 131 of the second hollow shell 130, and the second fiber layer 132 may define the outer surface of the second hollow shell. However, such layers may have any suitable arrangement relative to each other and to the inner and outer surfaces of their respective hollow shells. Furthermore, the inner and outer surfaces may include any suitable combination of fiber layers, energy dissipating materials, and / or other layers. Some additional non-limiting examples of alternative arrangements are described with reference to FIGS. 4A-4B, 5, and 6. Exemplary configurations of fiber layers, such as the first fiber layer 122, are further described below with reference to FIGS. 3A-3C.

[0059] It will be understood that the container 110, and other containers described elsewhere herein, may include any suitable combination of shapes suitable for at least partially enclosing the PV 100. Illustratively, the inner surface 121 of the hollow shell 120 may be shaped to conform to and contact the shape of the respective portion of the outer surface of the PV 100. Similarly, the inner surface 131 of the hollow shell 130 may be shaped to conform to and contact the shape of the respective portion of the outer surface of the PV 100. Thus, different portions of the hollow shells 120, 130 may be different shapes from one another and may have any suitable cross-section. Illustratively, at least one of the first and second inner surfaces 121, 131 is at least partially cylindrical, at least partially spherical, or at least partially conical. In the non-limiting example shown in FIGS. 1A-1B, a portion of the first inner surface 121 is cylindrical, another portion of the first inner surface 121 is spherical, and the inner surface 131 is spherical. Thus, first hollow shell 120 may be considered to define a first bowl shape, and second hollow shell 130 may be considered to define a second bowl shape. Other shapes can be readily envisioned to partially, substantially, or completely enclose a PV for use in any suitable context, such as a vehicle (car, truck, airplane, spacecraft, etc.). In this regard, the use of the term "substantially concentric" to describe the spatial relationship between two materials is not intended to imply that the materials necessarily have a particular shaped cross-section (e.g., cylindrical, conical, or spherical), but rather refers to materials having shapes that are substantially concentric with one another.

[0060] For example, Figures 2A-2B schematically illustrate cross-sectional views of an exemplary vessel assembly around a PV. In the non-limiting example shown in Figure 2A, vessel 210 includes a first hollow shell 220 defining a first half-cylinder and a second hollow shell 230 defining a second half-cylinder. In the non-limiting example shown in Figure 2A, first and second hollow shells 220, 230 meet at junction 240. Thus, the composite cross-section of vessel 210 may be substantially cylindrical in the region shown in Figure 2A. Vessel 210 may be a different shape in other regions (not specifically shown), if present.

[0061] Any suitable structure may be used to attach the first and second hollow shells to one another, e.g., to attach the first and second hollow shells 120, 130 to one another or to attach the first and second hollow shells 220, 230 to one another. Illustratively, the container 110 or 210 (or any other container provided herein) may include a first fastener attached to the first hollow shell and a second fastener attached to the second hollow shell and configured to engage with the first fastener to attach the first hollow shell to the second hollow shell. For example, in the container 210 shown in FIG. 2A , the first and second fasteners (collectively designated 250) may include respective portions of a toggle latch, a pipe clamp, or a bolted joint. If desired, the container 210 may also include a pad 260 disposed around the joint 240. As another example, the container 211 shown in FIG. 2B may be configured similarly to the container 110 shown in FIGS. 1A-1B, for example, and may include a first hollow shell 221 configured similarly to the first hollow shell 120 and a second hollow shell 231 configured similarly to the second hollow shell 130. The PV 100 may be partially, substantially, or completely enclosed within the container 211 by inserting the PV 100 into the first hollow shell 221, covering the exposed end of the PV with the second hollow shell 231, and fastening the first and second hollow shells together using first and second fasteners. In the container 211, the first and second fasteners (collectively designated 251) may comprise respective portions of a toggle latch, a pipe clamp, or a bolted joint, and may include padding 261. Alternatively, the first fastener may include a first thread, and the second fastener may include a second thread configured to rotatably engage with the first thread. That is, the first and second fasteners of the container 211 may be configured such that the second hollow shell 231 may be threaded into the first hollow shell 221 to define an interior volume that houses the PV 100 .

[0062] The first fibrous layer of a first hollow shell (e.g., hollow shell 120, 220, or 221) may include one or more plies, each of which may have any suitable configuration. Similarly, the second fibrous layer of a second hollow shell (e.g., hollow shell 130, 230, or 231) may include one or more plies, each of which may have any suitable configuration. The composition and material structure of the first fibrous layer of a first hollow shell may be similar to or different from the composition and material structure of the second fibrous layer of a second hollow shell. In some examples, the first fibrous layer, the second fibrous layer, or both the first and second fibrous layers may include a woven fabric, a braided layer, or one or more spiral plies. As used herein, the term "woven fabric" is intended to mean an element formed by intertwining two or more tows at right angles to each other. As used herein, the term "tow" is intended to mean a flexible member elongated along the tow's longitudinal axis, such as a thread, rope, filament, or tape. A tow may be monolithic or may include multiple fibers. In some examples, a tow may be at least partially impregnated with a resin and include multiple fibers elongated along the tow's longitudinal axis. As used herein, the term "braided layer" is intended to mean an element formed by intertwining three or more tows at non-perpendicular angles to one another. As used herein, the term "spiral" when referring to a ply is intended to mean that the tows of the ply are helically arranged within the ply. As used herein, the term "ply" is intended to mean a layer distinguishable from another layer by composition, material construction, or both. A ply may include one layer or multiple layers.

[0063] 3A-3C schematically illustrate exemplary configurations of different plies. In the non-limiting example shown in FIG. 3A, plies 321, 322, and 323 are spaced apart from PV 100 (e.g., they may be separated from PV 100 by an energy dissipative material or may be positioned adjacent to each other to form a fibrous layer). In the illustrated example, ply 321 may be the innermost ply of the first fibrous layer ("ply 1"), ply 322 may be outer than ply 321 ("ply 2"), and ply 323 may be the outermost ply of the first fibrous layer ("ply 3"), although it will be understood that the first fibrous layer may include any suitable number of plies. Plies 321, 322, and 323 may each be spiral. As shown in FIG. 3A, the tows of each ply may be wound adjacent to each other to form a single ply with a distinct ply orientation. For example, the tow (i=1) of ply 321 is angled θ with respect to the axis 320 of PV 100 (which may be coaxial with the inner surface 340 of the first hollow shell). i=1 The tow (i=2) of ply 322 may be wound adjacent to each other at an angle of θ i=2 The tow (i=3) of ply 323 may be wound adjacent to each other at an angle of θ i=3 The wires may be wound adjacent to each other at an angle of θ i=1 , θ i=2 , and θ i=3 denotes the fiber orientation of the tow relative to the global reference axis (here, the PV longitudinal axis 320). The difference between the tow orientations of adjacent plies, i.e., θ i=2 -θ i=1 is sometimes called the pitch angle. The difference in the angles of adjacent plies θ i=2 -θ i=1 , θ i=3 -θ i=2 , θ i=4 -θ i=3 are substantially identical to one another, the resulting plies may be said to have a constant pitch angle, and if the difference in orientation of such adjacent plies differs from one another, the resulting plies may be said to not have a constant pitch angle. i=2 is θ i=1and θ may differ from about 1 degree to about 25 degrees. i=3 is θ i=2 The angle θ may differ from about 1 degree to about 25 degrees. i=1 , θ i=2 , and θ i=3 As a result of this difference between the angles, the helical plies 321, 322, and 323 may be helically arranged relative to one another. Such a helical arrangement may provide additional crashworthiness to the vessel, and thus the PV 100. As used herein, "helical arrangement" or "helical layup," when referring to multiple plies, is intended to mean that the tows of adjacent plies are arranged at different angles relative to one another to define a helix. Thus, each of the plies 321, 322, and 323 may be helical, and the arrangement of the plies 321, 322, and 323 may also be helical. As used herein, "about" and "substantially" mean within ±10% of the stated value. Helically arranged plies allow for a smooth inter-ply (pitch) angle transition between adjacent plies. This results in a smooth transition in elastic properties and reduces interlaminar shear stresses at the interface between the plies. These stresses are responsible for the formation of delaminations during an impact event. Thus, a helical layup helps delay, reduce, or inhibit the onset of damage. Furthermore, spiral layups can dissipate energy primarily through the formation of matrix damage. For example, a crack can grow and propagate along a serpentine path following local fiber orientation (spiral cracking), thus leaving the majority of the fibers undamaged and leading to high energy dissipation, delayed, reduced, or inhibited catastrophic failure, and increased structural integrity. The crack can follow the local fiber orientation during propagation, thus inhibiting or preventing fiber (critical load-bearing component) failure. This results in extensive damage propagation at subcritical levels (i.e., before penetration or substantial loss of stiffness), characterized by the formation of matrix splits and a spiral distribution of delaminations.

[0064] The fibrous layer may include other arrangements of plies and / or tows within the plies. For example, FIG. 3B illustrates an example in which spiral plies include interwoven tows. In the non-limiting example shown in FIG. 3B, plies 331, 332, and 333 of the first fibrous layer of the first hollow member are spaced apart from the PV 100 (e.g., may be separated from the PV 100 by an energy dissipative material). In the illustrated example, ply 331 may be the innermost ply of the first fibrous layer ("ply 1"), ply 332 may be outside ply 321 ("ply 2"), and ply 333 may be the outermost ply of the first fibrous layer ("ply 3"), although it will be understood that the first fibrous layer may include any suitable number of plies. Plies 331, 332, and 333 may each be spiral. For example, as shown in FIG. 3B, the tow (i=1) of ply 331 is (+α i=1 +θ i=1 ) and (-α i=1 +θ i=1 The tow (i=2) of ply 332 may be interwoven at an angle of (+α i=2 +θ i=2 ) and (-α i=2 +θ i=2 The tow (i=3) of ply 333 may be interwoven at an angle of (+α i=3 +θ i=3 ) and (-α i=3 +θ i=3 The interwoven fabric may be woven at an angle of θ i=1 , θ i=2 , θ i=3 may be different from each other. For example, θ i=2 is θ i=1 and θ may differ from about 1 degree to about 25 degrees. i=3 is θ i=2 The angle α may vary from about 1 degree to about 25 degrees. i=1 , α i=2 , and α i=3 may be different from each other. For example, α i=2 is α i=1 may differ from about 1 degree to about 90 degrees from αi=3 is α i=2 The angle θ may vary from about 1 degree to about 90 degrees. i=1 , θ i=2 , and θ i=3 As a result of this difference between the helical plies 331, 332, and 333, the helical plies 331, 332, and 333 may be helically arranged relative to one another. Such a helical arrangement may impart additional crashworthiness to the vessel, and thus the PV 100. In layers without interwoven tows, the interface between adjacent plies within the layer may be represented by a smooth surface with a shape substantially equivalent to that of the shell. In layers with interwoven tows, the interface between adjacent plies is uneven due to the tows of adjacent plies crossing each other. During a crash or impact event on a PV, one of the significant failures likely to occur in a fiber-reinforced layer is delamination damage, i.e., separation between adjacent tows belonging to two adjacent plies. The presence of an uneven interface may restrict the delamination from deflecting from its original plane. This mechanism may impede, reduce, or inhibit the propagation of the delamination, thus resulting in improved crashworthiness.

[0065] 3C schematically illustrates a cross-section of a fiber layer 343 including a plurality of spiral plies 301-307 arranged helically relative to one another to form a spiral layup. Each of the spiral plies 301-307 includes a spiral tow 311 within a resin matrix 312. In the illustrated example, the orientation of the tows 311 within each ply 301-307 differs from one another (e.g., in a manner described with reference to FIG. 3A or 3B). The shape of the fiber layer 343 is concentric with the PV axis 320. The fiber layer 343 in the cross section shown in FIG. 3C may be, for example, the fiber layer 122 in the cross section 180 of the container 110 described with reference to FIGS. 1A and 1B, the fiber layer in the cross section 280 of the container 210 described with reference to FIG. 2A, the fiber layer in the cross section 281 of the container 211 described with reference to FIG. 2B (projected onto the volume shown in FIG. 3C), the fiber layer 422 in the cross section 480 of the container 410 described with reference to FIGS. 4A and 4B, the fiber layer 422′ in the cross section 480′ ... 3C ), the fiber layer 622 in cross section 680 of the first hollow shell 620 of the container described with reference to FIG. 6 , the fiber layer 622′ in cross section 680′ of the first hollow shell 620 of the container described with reference to FIG. 6 , the fiber layer 622″ in cross section 680″ of the first hollow shell 620 of the container described with reference to FIG. 6 , the fiber layer in cross section 780 of the overlap 700 described with reference to FIG. 7 , or the fiber layer in cross section 880 of the PV 800 described with reference to FIG. 8 . While seven spiral plies 301-307 are shown in FIG. 3C , it will be understood that any of the fiber layers provided herein may include any suitable number of plies, for example, about 1-20 plies, or about 2-15 plies, or about 3-10 plies, or about 4-8 plies. Optionally, each such ply may be spirally wound, and as a further option, the spirally wound plies may be helically arranged to provide one or more of the advantages as described herein.

[0066] As further described above with reference to FIGS. 1A-1B, the first hollow shell, the second hollow shell, or both the first and second hollow shells may include one or more additional layers. Illustratively, FIGS. 4A-4B schematically show a cross-sectional view of another exemplary container 410 for the PV 100. The container 410 at least partially surrounds the PV 100, and in some instances, substantially surrounds or completely surrounds the PV 100. In a manner similar to that described with reference to FIGS. 1A-1B, the container 410 may include a first hollow shell 420 and a second hollow shell 430. The first hollow shell 420 may include a first inner surface 421 configured to receive a first portion of the PV 100. The first hollow shell 420 may include a first fiber layer 422 substantially concentric with the first inner surface and at least partially impregnated with a resin. The first hollow shell 420 may also include a first energy dissipating material 423 substantially concentric with the first inner surface 421 and disposed between the first inner surface 421 and the first fiber layer 422. In the non-limiting example shown in Figures 4A-4B, the first hollow shell 420 may further include an additional fiber layer 422' substantially concentric with the first inner surface 421 and an additional energy dissipating material 423 substantially concentric with the first inner surface 421 and disposed between the first fiber layer 422 and the additional fiber layer 423. The additional fiber layer 422' may be at least partially impregnated with resin.

[0067] The second hollow shell 430 shown in FIGS. 4A-4B may include a second inner surface 431 configured to receive a second portion of the PV 100. The second hollow shell 430 may include a second fiber layer 432 substantially concentric with the second inner surface 431 and at least partially impregnated with a resin. The second hollow shell 430 may also include a second energy dissipating material 433 substantially concentric with the second inner surface 431 and disposed between the second inner surface and the second fiber layer. In a non-limiting example shown in FIGS. 4A-4B, the second hollow shell 420 may further include an additional fiber layer 432' substantially concentric with the second inner surface 431 and an additional energy dissipating material 433' substantially concentric with the second inner surface 431 and disposed between the second fiber layer and the additional fiber layer. The first and second hollow shells 420, 430 may be attachable to each other to define a volume for at least partially enclosing the PV 100. In the non-limiting example shown in Figure 4A, the first and second hollow shells 420, 430 meet one another at a joint 440. An exemplary structure for attaching the hollow shells to one another is described with reference to Figures 2A-2B.

[0068] In a non-limiting example shown in FIGS. 4A-4B , similar to that described with reference to FIGS. 1A-1B , a first energy dissipating material 423 may define the inner surface 421 of the first hollow shell 420, and a second energy dissipating material 433 may define the inner surface 431 of the second hollow shell 430. Additionally, an additional fiber layer 422′ may define the outer surface of the first hollow shell 420, and an additional fiber layer 432′ may define the outer surface of the second hollow shell 430. The additional fiber layers and additional energy dissipating materials provided in each of the first and second hollow shells 420, 430 may provide multiple levels of impact resistance. To provide additional impact resistance, one or both of the additional fiber layers 422′, 432′ may include multiple plies, such as spiral plies, which may be arranged spirally as needed, in a manner as shown in FIG. 4B . Optionally, one or more sensors may be embedded in or between one or more layers of the container 410. Sensors may include, for example, piezoelectric sensors configured to monitor impacts, fiber Bragg gratings (FBGs) configured to monitor gas leaks, etc. Such sensors may be attached to an appropriate monitoring system, for example, via wired or wireless communication paths. In one non-limiting example, FBG sensors record and monitor changes in local strain fields. Such changes are the result of the presence of damage. Thus, by placing FBG sensors at various depths within the shell, it is possible to detect the depth of damage within the crash box during an impact event. This can be used to determine the crash box's durability, remaining protective capacity, and whether it requires replacement or repair. The FBG signal can be processed by onboard live (wired or wireless) monitoring and calibrated to trigger recording upon the occurrence of specific changes in the monitored signal. Depending on the type of signal change, different types of damage can be distinguished. For example, a change in the peak of the recorded signal suggests the passage of a delamination, while a complete cutoff of the signal indicates the formation of a translaminar crack (severe damage) that destroys the optical fiber carrying the FBG sensor.The presence of a piezoelectric sensor, for example in the form of a polymer, can be used as both a leak detection indicator and a damage indicator during an impact. The piezoelectric sensor provides an indication of local changes in pressure, which can result from leaks from the PV as well as shock load-generating pressure conditions. The transmitted signal entity can be appropriately calibrated to correlate with the severity and location of potential leaks and impact damage events.

[0069] Additionally or alternatively, one or both of the energy dissipating materials 423, 433 may be shaped to provide additional impact resistance, as shown in FIG. 4A. For example, as shown in FIG. 4A, the first energy dissipating material 423 may be thicker in the spherical / bowl-shaped region configured to receive the first end of the PV 100, and the second energy dissipating material 433 may be thicker in the spherical / bowl-shaped region configured to receive the second end of the PV 100, thus providing additional cushioning against any impact to those end regions. Alternatively, one or both of the energy dissipating materials 423, 433 may have a substantially uniform thickness. Note that the first energy dissipating materials 123, 133 described with reference to FIGS. 1A-1B may similarly be shaped as described with reference to FIG. 4A and may be substantially uniform in thickness.

[0070] Additional and / or differently shaped energy dissipative materials may be included to further enhance impact resistance. For example, FIG. 5 schematically illustrates a cross-sectional view of another exemplary container 510 for a PV 100. The container 510 may be configured similarly to other containers described herein (e.g., containers 110, 210, 211, 410, or 610, details not specifically shown) and may include additional material 550 to cushion the corresponding end of the PV 100 from impact. Such additional material may be useful, for example, when one end of the PV 100 is particularly vulnerable to impact, such as forming the leading edge of a fuel tank. This region of the PV is, in fact, particularly susceptible to low-velocity impact damage during transportation and handling of the PV.

[0071] Still other configurations are contemplated. For example, FIG. 6 schematically illustrates a cross-sectional view of another exemplary enclosure for a PV. While FIG. 6 illustrates a cross-section of a first hollow shell 620 of the enclosure, it will be understood that a second hollow shell of the enclosure may be similarly or differently configured. In the example illustrated in FIG. 6, the first hollow shell 620 includes a first helically braided layer or woven fabric 660, which may be disposed at any suitable location within the first hollow shell. Illustratively, the first helically braided layer or woven fabric 660 may be disposed between the first inner surface 621 and the textile layer 622. Additionally or alternatively, the textile layer 622″ may define the inner surface of the first hollow shell 620. Optionally, an energy dissipative layer 623 may be disposed internally, for example, between the first helically braided layer or woven fabric 660 and the textile layer 622″. The first hollow shell 620 (as well as other hollow shells provided herein) may include any suitable number and arrangement of layers, which together may limit damage to the PV 100 due to a collision. Illustratively, the hollow shell 620 may include an additional spirally braided layer or woven fabric 660′ disposed outside the fabric layer 622, an additional energy dissipating layer 632′ disposed outside the additional spirally braided layer or woven fabric 660′, and an additional fabric layer 622′ disposed outside the additional energy dissipating layer 632′ and defining the outer surface of the first hollow shell 620.

[0072] Braids manufactured using 2D or 3D techniques offer the interesting property of diameter variation related to fiber angle variation. Because fibers can slide within a tubular braid, this allows the diameter of such braids to be expanded or contracted. This property can be advantageous for creating structures with a helicoidal architecture, in which several layers are effectively sleeved together, gradually expanding the diameter of the structure and slightly varying the fiber angle between and / or along the layers to create very small variations in clocking angle between two adjacent braided layers. Such braided fiber-reinforced structures can also be provided in the form of flat braided tapes, which are formed by cutting the tubular braid along its length and then laying it flat. The fiber angle orientation also varies with the width of the tape. Such braided tapes can also be used to create structures with a helicoidal architecture, with different layers of the same tape stacked with slightly different fiber angles. This property can also be found in woven fabrics that are tilted to change the initial 90° angle between the warp and weft yarns, which can be adjusted to create a series of warp / weft angles with small angle variations from one fabric layer to the next (e.g., a 5° clock angle to align layers at 90°, 85°, 80°, 75°, etc.), thus creating a structure with a helical configuration.

[0073] For example, in an example where a fiber layer is positioned adjacent to a helically braided layer or woven fabric, such as in the manner described with reference to FIG. 6, the resin of the fiber layer can at least partially impregnate the helically braided layer or woven fabric. For example, when filament winding is used, both pre-impregnated and dry fiber tows can be used. This means that some of the excess resin in the pre-impregnated tows can flow into the dry tows during curing of the container section. Depending on the excess resin in the pre-impregnated tows, a certain degree of partial impregnation of the dry tows can be achieved. Full or partial impregnation of the helically braided layer or woven fabric can improve impact resistance and gas leak detection, for example, using sensors as described elsewhere herein. Within a fiber-reinforced layer, alternating plies with higher degrees of fiber impregnation with plies with lower degrees of fiber impregnation results in variations in elastic properties between adjacent plies. These energy dissipation mechanisms, including crack deflection, crack arrest, and crack diffusion, enable greater damage tolerance and structural integrity of the fiber layer. The effectiveness of these mechanisms increases with the difference in elastic properties. Additionally, the presence of partially impregnated plies within the fibrous layer increases the flexibility of the shell, allowing for greater energy absorption under elastic deformation during an impact event before reaching the point of failure.

[0074] In examples where a hollow shell includes two or more layers of a similar type (e.g., two or more fiber layers, two or more energy dissipative materials, or two or more helically braided layers or woven fabrics), it will be understood that each layer of that type may have the same composition as one another, or the same material make-up as one another, or both the same composition and the same material make-up as one another. As used herein, the term "composition" is intended to refer to the materials contained in an element. As used herein, the term "material make-up" is intended to refer to the physical arrangement of materials contained in an element. For example, two elements having the same composition as one another may be made from substantially the same materials. These materials may have the same material make-up as one another, or different material make-ups as one another. Also, for example, two elements having different compositions from one another may have the same material make-up as one another, or different material make-ups as one another. Illustratively, a given ply may include tows having different longitudinal orientations from one another. Such tows may be part of the same elongated member.

[0075] In one non-limiting example, the inner fiber layer may include a helicoid with angles Δθ and α selected to arrest microcracking. Such an inner fiber layer may help protect against gas under pressure, while the outer fiber layer may have a different material composition than the inner fiber layer. For example, the outer fiber layer may include a helicoid with angles Δθ and α selected to protect against larger impacts, such as collisions. The range of Δθ and α to enhance microcracking resistance may be, for example, 30° to 90°. Furthermore, to further enhance microcracking resistance, thin ply tows may be used. The range of Δθ and α to protect against larger impacts should be 1° to 25°. Furthermore, any appropriate combination of thin, standard, and / or thick plies may be used to achieve good impact resistance and reduce material costs and layup time. A smaller range of Δθ and α may allow cracks to propagate primarily through the damping matrix according to the local fiber orientation determined by the helical layup. This allows a large amount of energy to be dissipated along a serpentine crack pattern in which the majority of the fibres remain intact, thus allowing the structural integrity of the shell to be maintained under severe impact events.

[0076] This distinction in the ranges of Δθ and α follows an analytical model that describes the evolution of the energy release rate (the energy required for a crack to propagate through a given material) at the front of a spiraling matrix crack growing in a spirally arranged layup. The equations describing the analytical model can be found in Mencattelli et al., "Realizing bio-inspired impact damage-tolerant thin-ply CFRP bouligand structures via promoting diffused sub-critical helicoidal damage," Composites Science and Technology, 182, 107684 (2019), the entire contents of which are incorporated herein by reference. This model describes the growth of a twisted spiral crack through an analysis of the local energy release rate (G) along the crack front, which starts from an initially flat state. The global reference system and the local reference system along the crack front completely define the crack front as it twists and kinks at any given time. Figure 14A shows a schematic representation of a model of crack propagation through an exemplary spiral layup. Figure 14B is a plot of energy release rate as a function of depth for different pitch angles in the model of Figure 14A. More specifically, Figure 14A shows a spiral crack initiating in ply (0) with fibers aligned at a 0° orientation and along the x-axis, which corresponds to the longitudinal axis of the PV, and then propagating in the z-direction (perpendicular to the longitudinal axis of the PV and radially of the PV) through additional plies (1), (2), (3), and (4). The surface of the crack can be described by the shaded curve 1401 shown in Figure 14A.A closed-form solution to the problem can be obtained by assuming that (i) the crack only destroys the matrix, which is isotropic; (ii) the crack front remains straight; (iii) other failure mechanisms such as delamination and fiber breakage do not occur; and (iv) the initially flat crack opens in mode I, i.e., the crack surface opens with displacements applied primarily along x, i.e., normal to the crack surface. This opening condition well describes an interlaminar crack propagating radially through the PV. Following these assumptions, it is possible to obtain an expression for the evolution of the energy release rate at the front of a spiral crack fully defined in the space x, y, and z of the PV.

[0077] 14B shows the energy release rate (G / G, a dimensionless quantity) for pitch angles (Δθ) of 2.5° (curve 1411), 5° (curve 1412), 10° (curve 1413), 20° (curve 1414), and 45° (curve 1415). For example, a spiral layer with Δθ=20° (curve 1414) has the following orientation θ relative to the longitudinal axis of the PV: i The spiral plies (curve 1412) with Δθ=5° were modeled to have plies stacked at: [0° / 20° / 40° / 60° / 80° / 100° / 120° / 140° / 160° / 180° / 200° / ... / 1440°]. The spiral plies (curve 1412) with Δθ=5° had the following orientation θ relative to the longitudinal axis of the PV: i The layup was modeled to have plies stacked at: [0° / 5° / 10° / 15° / 20° / 25° / 30° / 35° / 40° / 45° / 50° / ...715° / 720°]. Other layups (with other pitch angles) were modeled similarly. In this non-limiting example, the plies were stacked at 20 g / m 2The specimen is made of a thin ply of carbon / epoxy UD with a fiber areal weight of 1000 MPa. A higher energy release rate means that microcracking is promoted, allowing for diffuse damage and high energy dissipation. A lower energy release rate means that microcrack formation is less likely. Figure 14B shows the normalized energy release rate (G) required to grow a flat crack parallel to the xz plane shown in Figure 14A. Figure 14B shows that the energy release rate decreases as the pitch angle increases from 2.5° (curve 1411) to 5° (curve 1412), 10° (curve 1413), 20° (curve 1414), and 45° (curve 1415). Therefore, it can be seen from Figure 14B that decreasing Δθ reduces the crack resistance to spiral crack growth (under the dominant Mode I opening, such as under impact), facilitating microcrack propagation. This allows more energy to be dissipated while maintaining the integrity of the fiber and therefore the crash box. Increasing Δθ increases crack resistance against propagating spiral cracks (under the dominant Mode I opening) and delays, reduces, or inhibits the formation of microcracks, promoting the occurrence of catastrophic failure mechanisms such as delamination and fiber breakage. Thus, a larger Δθ allows for better microcrack resistance to avoid leakage (inner layers), while a smaller Δθ allows for better impact resistance and greater energy dissipation at the impact location (outer layers). The inner and outer fiber layers may also, or alternatively, have different compositions to enhance their respective performance for their intended functions. For example, the inner layer can be made of a tough material with high resistance to microcracks, such as a thin ply of carbon fiber embedded in a reinforced epoxy resin, while the outer layer can be made of a fiber reinforcement with higher ductility than carbon fiber, such as glass fiber and / or aramid fiber, or a combination of multiple fiber types.

[0078] Composite laminates containing stacks of thin-ply (TP) fiber reinforced materials can exhibit better mechanical properties and improved resistance to microcracking and delamination compared to parts of the same thickness produced using thicker plies. TP fiber reinforced materials require a higher applied load to form microcracks in the matrix in the longitudinal direction of the fibers (i.e., matrix splitting). This increased microcracking resistance results in improved delamination resistance. For example, commercially available aerospace unidirectional (UD) carbon / epoxy (C / E) prepregs are grade 190 (.0073 in. / ply) or grade 145 (.0056 in. / ply). TPUD is typically grade 75 (.003 in. / ply) or thinner. Grades are available in g / m 2 Specifies the nominal areal weight of carbon fiber in UD prepregs, measured at 1000 W. TP laminates allow for minimum gauge reduction and / or lighter equivalent performance structures. TP materials may include, for example, unidirectional (UD) tape, non-crimp fabric (NCF), or woven materials. Laminates may include ply stacks that are balanced (having approximately equal numbers of positively and negatively oriented plies), symmetrical (i.e., each ply above the midplane of the layup may have an identical ply (approximately the same material, thickness, and orientation) at approximately equal distances below the midplane).

[0079] It will be appreciated that any suitable material or combination of materials may be used in the container. For example, as noted above, the fibrous layer may be at least partially impregnated with a resin, such as a thermosetting or thermoplastic resin as known in the art. The resin may optionally be or include a flame retardant to further reduce the risk of explosion in the event of impact. In one non-limiting example, the resin in the outer composite shell may comprise a flame retardant material to reduce the possibility of fire damage in the event of a leak due to damage to the PV.

[0080] The fibrous layer may comprise any suitable material or combination of materials. For example, the fibrous layers provided herein may, independently of one another, comprise at least one material selected from the group consisting of ultra-high molecular weight polyethylene (UHMWPE), para-aramid, carbon, graphite, glass, aramid, basalt, ultra-high molecular weight polypropylene (UHMWPP), natural materials (e.g., hemp or flax), metal, quartz, ceramic, and recycled fibers. The fibers within the fibrous layer may be expected to act as load spreaders and sharp impact stoppers, distributing the energy of an impact over a larger surface of the energy dissipating material and thus limiting damage to the PV.

[0081] In some examples, the energy dissipative material may include a foam. The foam may include, for example, polyvinyl chloride (PVC), expandable polyurethane (PU), expanded polystyrene (EPS), expanded polypropylene (EPP), polyethylene (PE), aluminum foam, radially oriented scaffold 3D printing materials, honeycomb structures, closed-cell foam, open-cell foam, viscoelastic gel, or define a metamaterial. Honeycomb structures are commercially available, such as aluminum honeycomb or NOMEX®, a flame-retardant meta-aramid material commercially available from DuPont de Nemours, Inc. (Wilmington, Delaware). As used herein, the term "metamaterial" is intended to refer to a cellular hierarchical structure with similar properties at different length scales, such as those used in football helmets.

[0082] It will be understood that the first and second hollow shells of any of the containers provided herein may be used in any suitable manner to protect a PV. Such a method may include, for example, inserting a first portion of the PV into the first hollow shell of any of the containers, inserting a second portion of the PV into the second hollow shell of that container, and attaching the first hollow shell to the second hollow shell.

[0083] It will also be appreciated that the teachings herein may be used to protect a PV without necessarily forming a crash box separable from the PV. Illustratively, a method of protecting a PV may include covering a pressure vessel with multiple helical plies, the helical plies being helically arranged relative to one another. FIG. 7 schematically illustrates an exemplary overlap 700 for PV 100 (the inner ply of PV 100 is shown). The overlap 700 may include multiple helical plies, the helical plies being helically arranged relative to one another. Alternatively, the PV itself may be formed to include multiple helical plies, the helical plies being helically arranged relative to one another. FIG. 8 schematically illustrates an exemplary structure of a PV. PV 800 may include multiple helical plies, the helical plies being helically arranged relative to one another. In a similar manner as described with reference to FIG. 3A, the first helical ply (i=1) of the helical plies of PV 800 or overlap 700 is aligned with θ i=1 The second one of the spiral plies (i=2) may include a plurality of tows wound adjacent to each other at an angle of θ i=2 Optionally, the tow may include a plurality of tows wound adjacent to one another at an angle of θ i=2 is such that the plies define a helical arrangement. i=1 Alternatively, in a manner similar to that described with reference to FIG. 3B, the spiral plies may include interwoven tows. For example, the first of the spiral plies (i=1) may have an angle of (+α+θ i=1 ) and (-α+θ i=1 The second of the spiral plies (i=2) may include tows interwoven at an angle of (+α+θ i=2 ) and (-α+θ i=2 ) and optionally, θ i=2 is θ i=1 In one non-limiting example, at least a portion of the PV800 may be formed using a spiral layer conventionally wound on a sacrificial mandrel to withstand pressure loads and a second outer plurality of helically arranged plies to withstand impacts.

[0084] The vessel, PV overwrap, and PV may be fabricated using any suitable combination of operations. Figures 9-12 show exemplary flows of operations in respective methods for fabricating a vessel for a PV. Referring now to Figure 9, method 900 may include forming a first hollow shell (operation 910) and forming a second hollow shell, the first hollow shell attachable to the second hollow shell to at least partially enclose the PV. The first hollow shell may be formed using steps including molding a first energy dissipating material to form a first inner surface configured to receive a first portion of the pressure vessel (operation 911) and forming a first fiber layer at least partially impregnated with resin over the first energy dissipating material so as to be substantially concentric with the first energy dissipating material (operation 912). The second hollow shell may be formed using steps including molding a second energy dissipative material to form a second interior surface configured to receive the second portion of the pressure vessel (operation 921), and forming a second fibrous layer at least partially impregnated with resin over the second energy dissipative material so as to be substantially concentric with the second energy dissipative material (operation 922). The operations of method 900 may be used to prepare a vessel such as those described with reference to Figures 1A-1B, 2A-2B, 4A-4B, 5, or 6.

[0085] Illustratively, operations 911, 912, 921, and 922 may be performed using any suitable combination of operations as shown in FIGS. 10-12 . Referring now to FIG. 10 , method 1000 may include forming an energy dissipative material (core) on a shaped mandrel, e.g., molding a foam and forming or winding a honeycomb / foam strip of the core into the mandrel shape (operation 1010). Method 1000 may include winding a spiral layer onto the energy dissipative material (e.g., foam) in a spiral layup having a variable or constant pitch angle (operation 1020). The tow used to form the spiral layer may be at least partially impregnated with a resin. Method 1000 may include curing the structure (operation 1030). Method 1000 may include removing the mandrel (operation 1040). Method 1000 may include inserting a PV into the resulting container (crush box) (operation 1050). The container 110 described with reference to Figures 1A-1B is a non-limiting example of a container that may be made using operations such as those described with reference to Figure 10.

[0086] Referring now to FIG. 11 , method 1100 may include winding spiral layers onto a sacrificial mandrel in a spiral layup having a variable or constant pitch angle to form inner and outer shells (operation 1110). Method 1100 may include curing the resulting structure (operation 1120). Method 1100 may include removing the mandrel (operation 1130). Method 1100 may include injecting an energy dissipative material, such as expandable polyurethane (PU) foam, between the shells (operation 1140) to form a sandwich crush box. Method 1100 may include inserting a PV into the resulting container (crush box) (operation 1150). The resulting container may include inner and outer surfaces defined by respective fiber layers with the energy dissipative material disposed therebetween.

[0087] Referring now to FIG. 12 , method 1200 may include trimming an energy dissipative material, such as a foam core, to a mandrel shape (operation 1210). Method 1200 may include winding a spiral layer in a spiral layup having a variable or constant pitch angle (operation 1220). Method 1200 may include braiding the layers to form a spirally braided structure or using additional energy dissipative material, such as foam (operation 1230). Method 1200 may include impregnating the structure with a flame retardant additive resin (operation 1240). Method 1200 may include winding a spiral layer in a spiral layup (operation 1250). Operations 1230 through 1250 may be repeated any suitable number of times, such as once, twice, three times, or more than three times. Method 1200 may include curing the structure (operation 1260). Method 1200 may include removing the mandrel (operation 1270). Method 1200 may include inserting a PV into the resulting container (crush box) (operation 1280). The container described with reference to Figure 6 is a non-limiting example of a container that may be made using operations such as those described with reference to Figure 12.

[0088] 13 shows an exemplary flow of operations in a method 1300 for fabricating a PV. Method 1300 may include winding a spiral layer in a spiral (operation 1310). Method 1300 may include curing the structure (operation 1320). Method 1300 may include removing the mandrel (operation 1330). The PV described with reference to FIG. 8 is a non-limiting example of a PV that may be fabricated using operations such as those described with reference to FIG. 13.

[0089] It will be appreciated that the use of a separate protective crash box (container) as provided herein can reduce the weight and complexity of the PV. Indeed, in previously known fiber-reinforced composite PVs containing fibers, the fibers may always be under tensile stress due to pressurized gas. In fiber-reinforced composite materials, such a tensile state can result in reduced impact strength, as described, for example, in Kamarudin et al., "Effect of high velocity ballistic impact on pretensioned carbon fiber reinforced plastic (CFRP) plates," IOP Conference Series: Materials Science and Engineering 165(1):012005 (2017), the entire contents of which are incorporated herein by reference. The inventors recognized that previously known composite PVs have been overbuilt to relieve tensile stress; for example, overbuilding a PV can improve impact performance while also increasing structural weight, thus resulting in an inefficient design. In comparison, the separate protective container provided herein does not need to be pressurized, and therefore impact properties are not reduced and materials can be used more efficiently.

[0090] In some examples, such as those described with reference to Figures 4A-4B and 6, the vessel can be constructed with a multi-core structure having alternating spiral sublaminates and layers of energy dissipative material (e.g., foam). Such an arrangement can create a periodic change in elastic properties that is expected to function as a crack arrest mechanism for impact damage. This is expected to impart multiple impact resistance to the vessel, which in turn is expected to extend the operational life of the PV.

[0091] In another example, a multicore structure may include alternating spiral sublaminates and partially impregnated dry fiber reinforcement layers. Partial impregnation may be achieved using over-impregnated filament-wound spiral sublaminates to bleed out excess resin and partially impregnate the dry fiber layers. This may not only improve crash performance, but also form a leak detection system at different stages within the crash box. Additionally or alternatively, the partially impregnated layers may provide periodic variations in elastic properties that promote crack arrest and higher damage tolerance.

[0092] Additionally or alternatively, the energy dissipation material (e.g., foam core) may be equipped with piezoelectric / FBG sensing that responds to pressure / strain. The most outer layer may be used to detect impact damage and its depth without requiring downtime to repair the crash box. This may provide live monitoring of the safety margin changes of the crash box. For example, the innermost layer of the energy dissipation material in contact with the PV may include sensors configured to detect eventual leaks. However, it will be appreciated that by having the vessel, rather than the pressure vessel, absorb impact damage, the downtime of the storage / fuel cell unit following such an impact may be relatively short.

[0093] In some examples, at least a portion of the inner shell of the vessel closer to the pressure vessel can be made from helically arranged UHMWPE, para-aramid fibers, or other fibers disclosed herein. Such helically arranged materials can be expected to provide a relatively large reduction in backside deflection during impact and high-velocity impact, resulting in less blunting during an impact event. This is expected to further reduce the likelihood of an impact penetrating the vessel and transferring momentum to a localized region within the PV, further improving impact tolerance.

[0094] It is further noted that helical fiber arrangements can facilitate the dissipation of energy from impact through the formation of matrix damage, including helical matrix splitting and delamination. Some examples herein may include embedded thermoplastic strips of fiber reinforcement material or thermoplastic veils that can be used to "repair" such matrix damage. For example, heat and / or pressure can be applied to a damaged container, melting the thermoplastic material and refilling the cracked matrix. This can significantly extend the usable life of the container.

[0095] Additionally, as described in more detail above, the present container may include two or more parts to easily accommodate insertion of a PV. In this way, the container can be easily replaced if damaged (and repaired, if necessary, in the manner described above). Illustratively, two identical half shells may be assembled and connected around the sagittal plane defined by the PV shape, e.g., in the manner described with reference to FIG. 2A. Alternatively, a hollow shell may be formed to define axisymmetrical symmetry across the container shape with a dome opening for sliding the HPV therein, e.g., in the manner described with reference to FIG. 2B. In some examples, the container may be installed after pressurization to limit changes in stress or load on the container that might otherwise reduce its impact resistance.

[0096] While several example operations for preparing the present container are described with reference to Figures 9-12, it will be understood that the present container can be prepared using any suitable combination of techniques, including, but not limited to, resin transfer molding, injection molding, compression press molding, fiber winding, and automated fiber placement. As with the method described with reference to Figure 10, fibers may be placed directly on the energy dissipating material. Alternatively, as with the method described with reference to Figure 11, fibers may be placed on a mandrel / male mold to form a shell, and the energy dissipating material (e.g., a foam such as expandable PU) may be injected inside the shell; a smaller male mandrel may be used, leaving a radial space that defines the thickness of the foam liner. In yet another example, preparing the container may include filament winding a fiber layer helically onto a closed-cell axisymmetric mandrel to form the core of the structure, or onto an axisymmetric mandrel to ensure high compression of the plies, and the energy dissipating material may be inserted after the shell is manufactured. Additionally or alternatively, the energy dissipating material may be 3D printed, milled, or stamped. Additionally or alternatively, the energy dissipative material may include or consist of a filament wound flexible foam, which itself may be spirally or helically wound.

[0097] As is evident from examples such as those described with reference to Figures 1A-1B and 2B, the use of an at least partially cylindrical central section with one or two openings may allow sliding access to the PV from both sides. In some examples, the cap may be configured to allow access to the inlet (neck) of the container and may at least partially cover the connecting pipe. A threaded end cap, such as that described with reference to Figure 2B, is one example of how a cap may be attached to an at least partially cylindrical central section.

[0098] While various illustrative embodiments of the present invention have been described above, it will be apparent to those skilled in the art that various changes and modifications can be made therein without departing from the invention. It is intended in the appended claims to cover all such changes and modifications that fall within the true spirit and scope of the invention.

Claims

1. A container for a pressure vessel, a first hollow shell including a first inner surface configured to receive a first portion of the pressure vessel; a first fibrous layer substantially concentric with the first inner surface and at least partially impregnated with a resin; a first energy dissipative material substantially concentric with the first inner surface and disposed between the first inner surface and the first fiber layer; a first hollow shell comprising: a second hollow shell including a second inner surface configured to receive a second portion of the pressure vessel; a second fibrous layer substantially concentric with the second inner surface and at least partially impregnated with a resin; a second energy dissipative material substantially concentric with the second inner surface and disposed between the second inner surface and the second fiber layer; a second hollow shell comprising: Equipped with The vessel, wherein the first and second hollow shells are attachable to one another to define a volume for at least partially enclosing the pressure vessel.

2. 10. The container of claim 1, wherein at least one of the first and second interior surfaces is at least partially cylindrical, at least partially spherical, or at least partially conical.

3. 3. The container of claim 1 or claim 2, wherein at least one of the first and second interior surfaces is at least partially axisymmetric.

4. 4. The vessel of claim 1, wherein the first and second hollow shells define a volume for substantially enclosing the pressure vessel.

5. 5. The container of claim 1, wherein the first hollow shell defines a first half-cylinder and the second hollow shell defines a second half-cylinder.

6. 6. The container of claim 1, wherein the first hollow shell defines a first bowl shape and the second hollow shell defines a second bowl shape.

7. The container of claim 1 , wherein at least one of the first and second fibrous layers comprises a plurality of spiral plies.

8. The container of claim 7 , wherein the spiral plies are arranged spirally relative to each other.

9. The first helical ply (i=1) of the helical plies is angled θ with respect to the axis. ｉ＝１ 9. The container of claim 8, comprising a plurality of tows wound adjacent to one another at an angle of .

10. The second helical ply (i=2) of the helical plies is angled θ with respect to the axis. ｉ＝２ 10. The container of claim 8 or claim 9, comprising a plurality of tows wound adjacent to one another at an angle of .

11. θ ｉ＝２ is θ ｉ＝１ 11. The container of claim 10, wherein the temperature differs from about 1 to about 25 degrees.

12. The container of claim 8 , wherein the spiral ply comprises interwoven tows.

13. The first helical ply (i=1) of the helical plies is (+α ｉ＝１ +θ ｉ＝１ ) and (-α ｉ＝１ +θ ｉ＝１ 13. The container of claim 12, comprising tows interwoven at an angle of 0.5°.

14. The second helical ply (i=2) of the helical plies is (+α ｉ＝２ +θ ｉ＝２ ) and (-α ｉ＝２ +θ ｉ＝２ 14. The container of claim 12 or claim 13, comprising tows interwoven at an angle of 0.5°.

15. θ ｉ＝２ is θ ｉ＝１ 15. The container of claim 14, wherein the temperature differs from about 1 to about 25 degrees.

16. 16. The container of claim 1, wherein the first energy dissipative material defines the interior surface of the first hollow shell.

17. 17. The container of claim 1, wherein the first fibrous layer defines an exterior surface of the first hollow shell.

18. 18. The container of claim 1, wherein the second energy dissipative material defines the interior surface of the second hollow shell.

19. 19. The container of any one of claims 1 to 18, wherein the second fibrous layer defines an outer surface of the second hollow shell.

20. The first hollow shell is a third fibrous layer substantially concentric with the first inner surface; a third energy dissipative material substantially concentric with the first inner surface and disposed between the first and third fiber layers; and 20. The container of any one of claims 1 to 19, further comprising:

21. The second hollow shell is a fourth fibrous layer substantially concentric with the second inner surface; a fourth energy dissipative material substantially concentric with the second inner surface and disposed between the second fibrous layer and the fourth fibrous layer; 21. The container of any one of claims 1 to 20, further comprising:

22. 22. The container of any one of claims 1 to 21, wherein the first hollow shell comprises a first spirally braided layer or woven fabric disposed between the first inner surface and the first fibrous layer.

23. 23. The container of any one of claims 1 to 22, wherein the second hollow shell comprises a second spirally braided layer or woven fabric disposed between the second inner surface and the second fibrous layer.

24. The second hollow shell comprises a second spirally braided layer or woven fabric disposed between the second inner surface and the second fiber layer; 23. The container of claim 22, wherein the resin of the first fibrous layer at least partially impregnates the first spirally braided layer or woven fabric, or the resin of the second fibrous layer at least partially impregnates the second spirally braided layer or woven fabric.

25. 25. The container of any one of claims 1 to 24, wherein the fibers of the first and second fibrous layers independently comprise at least one material selected from the group consisting of ultra-high molecular weight polyethylene (UHMWPE), para-aramid, carbon, graphite, glass, aramid, basalt, ultra-high molecular weight polypropylene (UHMWPP), natural materials, metals, quartz, ceramics, and recycled fibers.

26. 26. The container of any one of claims 1 to 25, wherein at least one of the first and second energy dissipative materials comprises foam.

27. 27. The container of claim 26, wherein the foam comprises polyvinyl chloride (PVC), expandable polyurethane (PU), expanded polystyrene (EPS), expanded polypropylene (EPP), polyethylene (PE), aluminum foam, radially oriented scaffold 3D printing material, honeycomb structure, closed cell, open cell, viscoelastic gel, or defines a metamaterial.

28. 28. The container of any one of claims 1 to 27, wherein the first fibrous layer comprises substantially the same composition as the second fibrous layer.

29. 28. The container of any one of claims 1 to 27, wherein the first fibrous layer comprises a different composition than the second fibrous layer.

30. 30. The container of any one of claims 1 to 29, wherein the first fibrous layer comprises substantially the same material composition as the second fibrous layer.

31. 30. The container of any one of claims 1 to 29, wherein the first fibrous layer comprises a different material composition than the second fibrous layer.

32. 32. The container of any one of claims 1 to 31, wherein the first energy dissipative material comprises substantially the same composition as the second energy dissipative material.

33. 32. The container of any one of claims 1 to 31, wherein the first energy dissipative material comprises a different composition than the second energy dissipative material.

34. 33. The container of any one of claims 1 to 32, wherein the first energy dissipative material comprises substantially the same material composition as the second energy dissipative material.

35. 33. The container of any one of claims 1 to 32, wherein the first energy dissipative material comprises a different material composition than the second energy dissipative material.

36. a first fastener attached to the first hollow shell; a second fastener attached to the second hollow shell and configured to engage with the first fastener to attach the first hollow shell to the second hollow shell; 36. The container of any one of claims 1 to 35, further comprising:

37. 37. The container of claim 36, wherein the first fastener comprises a first thread and the second fastener comprises a second thread configured to rotatably engage the first thread.

38. 37. The vessel of claim 36, wherein the first fastener comprises a toggle latch, a pipe clamp, or a bolted joint.

39. 1. A method of protecting a pressure vessel having a first portion and a second portion, comprising: Inserting the first portion of the pressure vessel into a first hollow shell of a vessel according to any one of claims 1 to 38; Inserting the second portion of the pressure vessel into a second hollow shell of a vessel according to any one of claims 1 to 38; attaching the first hollow shell to the second hollow shell; A method comprising:

40. 1. A method of manufacturing a container for a pressure vessel, comprising: A first hollow shell molding a first energy dissipative material to form a first interior surface configured to receive a first portion of the pressure vessel; and forming a first fibrous layer at least partially impregnated with a resin over the first energy dissipative material so as to be substantially concentric with the first energy dissipative material; forming the material using steps including: A second hollow shell molding a second energy dissipative material to form a second interior surface configured to receive a second portion of the pressure vessel; and forming a second fibrous layer at least partially impregnated with resin over the second energy dissipative material so as to be substantially concentric with the second energy dissipative material; forming the material using steps including: Including, the first hollow shell is attachable to the second hollow shell to at least partially enclose the pressure vessel; method.

41. 39. The container of any one of claims 1 to 38, further comprising a sensor embedded in or between one or more layers of the container.

42. 42. The container of claim 41, wherein the sensor comprises a piezoelectric sensor configured to monitor for impact.

43. 43. The vessel of claim 41 or claim 42, wherein the sensor comprises a fiber Bragg grating (FBG) configured to monitor for gas leaks.

Images