Sandwich panels and methods of manufacturing sandwich panels

Sandwich panels (10) comprise a first microtruss panel (12), a second microtruss panel (18), and a damping film (26). The first microtruss panel (12) comprises a first outer skin (14) and a first microtruss structure (16) integral with the first outer skin (14). The second microtruss panel (18) comprises a second outer skin (20) and a second microtruss structure (22) integral with the second outer skin (20). The damping film (26) is positioned between and engaged with the first microtruss panel (12) and the second microtruss panel (18) opposite the first outer skin (14) and the second outer skin (20).

FIELD

The present disclosure relates to sandwich panels and methods of manufacturing sandwich panels.

BACKGROUND

Due to their high structural rigidity and low mass, sandwich panels are used to construct a variety of components in various industries, such as in the manufacture of aircraft, spacecraft, marine vehicles, land vehicles, and other apparatuses. Various equipment may be mounted to sandwich panels, and in some applications, the equipment may impart undesirable vibrations through the sandwich panels.

SUMMARY

Sandwich panels according to the present disclosure comprise a first microtruss panel, a second microtruss panel, and a damping film. The first microtruss panel comprises a first outer skin and a first microtruss structure integral with the first outer skin. The second microtruss panel comprises a second outer skin and a second microtruss structure integral with the second outer skin, wherein the second microtruss structure comprises second truss elements. The damping film is positioned between and engaged with the first microtruss panel and the second microtruss panel opposite the first outer skin and the second outer skin.

Methods for manufacturing sandwich panels according to the present disclosure comprise additively manufacturing a first microtruss panel, additively manufacturing a second microtruss panel, and coupling a damping film between the first microtruss panel and the second microtruss panel.

DESCRIPTION

FIG.1schematically illustrates sandwich panels10, sandwich-panel assemblies100, and apparatuses110according to the present disclosure. Generally, inFIG.1, elements that are likely to be included in a given example are illustrated in solid lines, while elements that are optional to a given example are illustrated in broken lines. However, elements that are illustrated in solid lines are not essential to all examples of the present disclosure, and an element shown in solid lines may be omitted from a particular example without departing from the scope of the present disclosure.

As schematically illustrated inFIG.1, a sandwich panel10may be a component of a sandwich-panel assembly100and/or an apparatus110. For example, a sandwich-panel assembly100may comprise a sandwich panel10and equipment102that is operatively coupled to the sandwich panel10. Examples of apparatuses110, which may include one or more sandwich panels10and/or one or more sandwich-panel assemblies100, include, but not are limited to, vehicles such as spacecraft, aircraft, marine vehicles, and land vehicles, as well as equipment, machinery, buildings, etc. Sandwich panels10may be structural panels of an apparatus110and/or may be used as an equipment panel within an apparatus110, that is, for securing equipment102thereto. Illustrative non-exclusive examples of equipment102include pumps, compressors, fans, motors, fly wheel assemblies, reciprocators, and other equipment that may create and/or transmit vibrations to a sandwich panel10to which it is coupled; however, sandwich panels10are not limited to being used with vibration-inducing equipment.

As schematically illustrated inFIG.1, sandwich panels10comprise at least a first microtruss panel12, a second microtruss panel18, and a damping film26that is positioned between and engaged with the first microtruss panel12and the second microtruss panel18. In some examples, the first microtruss panel12forms a first percentage of the core of the sandwich panel10and the second microtruss panel18forms a second percentage of the core of the sandwich panel10. In some such examples, the damping film26may form the remaining percentage of the sandwich panel10. The damping film26is provided to attenuate vibrations emanating from equipment102coupled to the sandwich panel10. The representation of the first microtruss panel12and the second microtruss panel18inFIG.1are schematic in nature and do not limit the microtruss panels to the schematically illustrated configuration. For example, while the first microtruss panel12, the second microtruss panel18, and the sandwich panel10itself are schematically represented in a generally flat or planar configuration inFIG.1, sandwich panels and their component parts may take any various configurations, including curved and complex configurations.

The first microtruss panel12may be substantially identical to the second microtruss panel18. As used herein, “substantially identical” includes at least 75% of the recited similarity or relationship. For example, a first microtruss panel12that is substantially identical to a second microtruss panel18includes a first microtruss panel12that is 75-100% identical to a second microtruss panel18.

As schematically represented inFIG.1, the first microtruss panel12comprises a first outer skin14and a first microtruss structure16that is integral with the first outer skin14, and the first microtruss structure16comprises first truss elements24. Similarly, the second microtruss panel18comprises a second outer skin20and a second microtruss structure22that is integral with the second outer skin20, and the second microtruss structure22comprises second truss elements30. In some examples, the first outer skin14and the first microtruss structure16of the first microtruss panel12are substantially identical with the second outer skin20and the second microtruss structure22of the second microtruss panel18.

The outer skins of microtruss panels are expansive thin layers of material, from which at least a subset of the truss elements of the microtruss structures extend. The outer skins additionally or alternatively may be described as sheets or facesheets. The outer skins14,20of sandwich panels10provide surfaces to which equipment102may be mounted and carry in-plane and bending loads applied to sandwich panels10, whereas the microtruss structures16,22(i.e., the core) of sandwich panels10react out-of-plane shear loads.

In some examples, the outer skins14,20have constant thicknesses across their entireties. Alternatively, the outer skins14,20may have varying thicknesses and/or areas of different thicknesses. For example, one or both of outer skins14and20may have a greater thickness in locations for mounting equipment102.

As schematically illustrated in dashed lines inFIG.1, the first outer skin14may comprise a plurality of first-outer-skin ridges48. Similarly, the second outer skin20may comprise a plurality of second-outer-skin ridges50. Such ridges additionally or alternatively may be described as ribs or reinforcing ribs. When present, the ridges48,50may have any suitable structure for providing structural reinforcement to the outer skins14,20and thus to the sandwich panel10. For example, ridges48,50may provide reinforcement to prevent buckling and/or dimpling of the outer skins14,20. In some examples, a plurality of first-outer-skin ridges48provides stability for the first outer skin14during manufacturing and use. Each ridge of the plurality of first-outer-skin ridges48may be integrally connected to the first outer skin14and/or to two or more truss elements of the plurality of truss elements24. In some examples, each ridge of the plurality of first-outer-skin ridges48extends between two truss elements24,30, such that each ridge intersects another at the midpoint of both ridges. In some such examples, the location of an intersection of two ridges corresponds to a node of plurality of nodes28.

Microtruss structures, which also may be referred to as microlattice structures, are structures with dimensions close to or within a range of millimeters to micrometers and having a periodic open cell structure with interconnected truss elements, which also may be referred to as struts. Microtruss structures additionally or alternatively may be described as space structures or 3D truss structures and as having a repeating pattern of a plurality of truss elements intersecting at a plurality of nodes.

Microtruss structures16,22may be constructed utilizing various techniques, including (but not limited to) various additive manufacturing techniques, investment casting, deformation forming, textile weaving, selective laser melting, electron beam melting, and self-propagating waveguide techniques. Examples of suitable additive manufacturing techniques include (but are not limited to) powder bed fusion and directed energy deposition. Moreover, microtruss structures16,22may be constructed of various materials, including metals and polymers, depending on the ultimate application of a given sandwich panel10.

As schematically illustrated inFIG.1, in some examples, the first microtruss structure16comprises, or defines, first nodes28at intersections of two or more first truss elements24, and the second microtruss structure22comprises second nodes32at intersections of two or more second truss elements30. Accordingly, the microtruss structures of sandwich panels10may be described as an open-cell configuration. In some examples, truss elements are circular in a cross-section. The cross-section of individual truss elements24and/or30may vary in diameter and/or thickness along the length of a truss element24and/or30. For example, first truss elements24may be larger in diameter nearer to first outer skin14and thinner nearer to the first medial skin34, or vice versa. The density, diameter, and/or length of truss elements24and/or30may vary depending on the application. For example, the density, diameter, and/or length of truss elements24and/or30may vary depending on expected stresses on and/or in the sandwich panel10. In some such examples, the density, diameter, and/or length of truss elements24,30may determine a thickness of their respective microtruss structures16,18. Moreover, the thickness of the first microtruss structure16may be different from the thickness of the second microtruss structure22.

WhileFIG.1schematically illustrates each of microtruss structures16and18as having only a single layer of cells, any suitable number of layers may be incorporated into the microtruss structures16,22of sandwich panels10. In some examples, a thickness of each microtruss structures16,18is determined by the number of cells. Moreover, the first microtruss structure16and the second microtruss structure22need not have the same number of layers of cells or otherwise be identically constructed, depending on the ultimate application for a sandwich panel10. For example, the first microtruss structure16may have a thickness greater than the second microtruss structure22. In some examples, the density of cells for microtruss structures16and/or18varies. For example, the density of cells may vary depending on the density of the truss elements.

In some examples, the first truss elements24and the first outer skin14define a plurality of first-microtruss-panel square pyramids52. Similarly, in some examples, the second truss elements30and the second outer skin20define a plurality of second-microtruss-panel square pyramids54. That is, the open cells of the microtruss structures may be square pyramids, although other shapes also may be utilized and incorporated into the microtruss structures of sandwich panels10. For example, the first truss elements24and the first outer skin14may define a plurality of first-microtruss-panel triangular pyramids, rectangular prisms, or prism shapes, etc. Similarly, the second truss elements30and the second outer skin20may define a plurality of second-microtruss-panel triangular pyramids, rectangular prisms, or other prism shapes, etc. In some examples, the triangular faces of the plurality of first-microtruss-panel square pyramids52are configured to be equilateral triangles. Similarly, in some examples, the triangular faces of the plurality of second-microtruss-panel square pyramids54are configured to be equilateral triangles.

As optionally represented in dashed lines inFIG.1, in some examples, the first microtruss panel12further comprises a first medial skin34that is integral with the first microtruss structure16opposite the first outer skin14. That is, the first microtruss structure16may be sandwiched between the first outer skin14and the first medial skin34. In some such examples, at least a subset of the first truss elements24terminate at the first medial skin34, such as with at least a subset of the first nodes28coinciding with the first medial skin34. However, in other examples the first medial skin34may not coincide with first nodes28, and instead, at least a subset of the first truss elements24may terminate at the first medial skin34without a corresponding first node28.

The first medial skin34, when present, provides structure for operative coupling of the first microtruss panel12to the damping film26beyond just the first nodes28or terminal ends of the first truss elements24. Although not represented inFIG.1, in some examples, the first medial skin34defines a first-medial-skin lattice structure36having a plurality of first-medial-skin voids35. In some such examples, the first-medial-skin lattice structure36has a cross-shape, with the intersections of each cross located and integrally connected to a node of the plurality of first nodes28. By having a lattice structure, the mass of the first medial skin34is reduced, and the sizes of the first-medial-skin voids35may be selected such that the resulting surface area of the first medial skin34is sufficient for operative coupling to the damping film26. Alternatively, the first medial skin34may have a continuous surface, and such a continuous surface may be substantially identical to the first outer skin14.

Similarly, as optionally represented in dashed lines inFIG.1, in some examples, the second microtruss panel18further comprises a second medial skin38that is integral with the second microtruss structure22opposite the second outer skin20. That is, the second microtruss structure22may be sandwiched between the second outer skin20and the second medial skin38. In some such examples, at least a subset of the second truss elements30terminate at the second medial skin38, such as with at least a subset of the second nodes32coinciding with the second medial skin38. However, in other examples the second medial skin38may not coincide with the second nodes32, and instead, at least a subset of the second truss elements30may terminate at the second medial skin38without a corresponding second node32.

As with the first medial skin34, the second medial skin38, when present, provides structure for operative coupling of the second microtruss panel18to the damping film26beyond just the second nodes32or terminal ends of the second truss elements30. Although not represented inFIG.1, in some examples, like the first medial skin34, the second medial skin38defines a second-medial-skin lattice structure40having a plurality of second-medial-skin voids42. In some such examples, the lattice structure has a cross-shape, with the intersections of each cross located and integrally connected to a node of the plurality of second nodes32. By having a lattice structure, the mass of the second medial skin38is reduced, and the sizes of the second-medial-skin voids42may be selected such that the resulting surface area of the second medial skin38is sufficient for operative coupling to the damping film26. Alternatively, the second medial skin38may have a continuous surface, and such a continuous surface may be substantially identical to the second outer skin20.

The damping film26of the sandwich panel10comprises any suitable films, sheets, skins, etc. configured to attenuate vibrations in the sandwich panel10. In particular, the damping film26may be made of any material suitable for attenuating vibrations, such as (but not limited to) acrylic tape and/or synthetic rubber. In some examples, the material, thickness, and/or durometer of the damping film26are selected based on the type of loading to be used on the sandwich panel10(e.g., the types of equipment expected to be used) and/or vibrational modes. For example, the material, thickness, and/or durometer of the damping film26may be selected based on vibrations such as broad range random vibrations (20-2000 Hz), sine vibrations (10-100 Hz), vibrations from the acoustic environment, vibrational frequencies generated from resonance equipment, and/or specific frequencies due to mounted equipment102.

In some examples, the damping film26is configured to attenuate vibrations present in the sandwich panel10. In some such examples, the damping film26is configured to attenuate vibrations through friction. For example, the damping film26may be configured to attenuate vibrations through internal friction and converting vibrational energy into heat. Alternatively, the damping film26may be configured to attenuate vibrations through resisting and/or preventing movement in the first microtruss panel12and/or the second microtruss panel18. In some such examples, damping film26may be configured to absorb and dissipate the shear strain energy by, for example, converting the energy into heat. In some examples, the damping film26is configured to achieve a damping level that is determined by the mounted equipment102. Possible damping levels include underdamping, overdamping, and/or critical damping. In some examples, the damping film26is configured to prevent vibrations from transferring to the surrounding environment from the sandwich panel10, as well as to reduce vibrational interference on the mounted equipment102. The damping film26may be positioned to dampen different vibrational modes. For example, the damping film26may be positioned on the neutral axis of the sandwich panel10, such that certain vibrational modes are damped. For example, the damping film26may be equidistant from the first outer skin14and the second outer skin20. In other examples, the neutral axis of the sandwich panel10may not be equidistant from the first outer skin14and the second outer skin20. In some examples, damping film26is positioned to absorb shear strain energy in sandwich panel10. For example, in a symmetric sandwich panel, the maximum transverse shear occurs at the centerline or the center plane (i.e., equidistant between the first outer skin14the second outer skin20, and damping film26may be positioned at the centerline or the center plane so to absorb the shear strain energy.

In some examples, the damping film26defines a damping-film lattice structure44having a plurality of damping-film voids46, as schematically indicated inFIG.1. By having such a lattice structure, the mass of the damping film26is reduced, and the sizes of the damping-film voids46may be selected to result in a desired level of damping by the damping film26. Additionally, when a sandwich panel10comprises optional medial skins34,38, the damping-film lattice structure44may correspond with a first-medial-skin lattice structure36and a second-medial-skin lattice structure40.

In some examples, the damping film26is adhered to the first microtruss panel12and to the second microtruss panel18. In some examples, being adhered to the microtruss panels12,18determines the position of the damping film26within the sandwich panel10. For example, differences in the thicknesses between the microtruss structures16,22may position the damping film26such that the damping film26is not equidistant from the first outer skin14and the second outer skin20when adhered to the microtruss panels12,18. In other examples, being adhered to the microtruss panels12,18positions the damping film26at the centerline of the sandwich panel10.

With continued reference toFIG.1, in some examples, the first microtruss panel12comprises one or more first-microtruss-panel mounts104for operative coupling of equipment102to the sandwich panel10. Similarly and as also schematically and optionally represented inFIG.1, in some examples, the second microtruss panel18comprises one or more second-microtruss-panel mounts106for operative coupling of equipment102to the sandwich panel10. In some examples, such mounts104,106may be integral with the respective outer skins14,20, such as additively manufactured therewith. In other examples, such mounts104,106may be operatively coupled to the respective outer skins14,20. The mounts104,106may take any suitable form depending on the nature of the equipment102to be coupled to a sandwich panel, including (but not limited to), inserts, through-bushings, embedded fittings, threaded mounts, etc.

Turning now toFIGS.2-3, an illustrative, non-exclusive example of a sandwich panel10. Where appropriate, the reference numerals from the schematic illustration ofFIG.1are used to designate corresponding parts of the example sandwich panel10; however, the example ofFIGS.2-3are non-exclusive and do not limit sandwich panels10to the illustrated embodiment ofFIGS.2-3. That is, sandwich panels10are not limited to the specific embodiment ofFIGS.2-3, and sandwich panels10may incorporate any number of the various aspects, configurations, characteristics, properties, etc. of sandwich panels10that are illustrated in and discussed with reference to the schematic representations ofFIG.1and/or the embodiment ofFIGS.2-3, as well as variations thereof, without requiring the inclusion of all such aspects, configurations, characteristics, properties, etc. For the purpose of brevity, each previously discussed component, part, portion, aspect, region, etc. or variants thereof may not be discussed, illustrated, and/or labeled again with respect to the example ofFIGS.2-3; however, it is within the scope of the present disclosure that the previously discussed features, variants, etc. may be utilized with the example ofFIGS.2-3.

FIG.4schematically provides a flowchart that represents illustrative, non-exclusive examples of a method200for additively manufacturing sandwich panels10and/or sandwich-panel assemblies100according to the present disclosure. Not all methods according to the present disclosure are required to include the steps illustrated. The methods and steps illustrated inFIG.4are not limiting and other methods and steps are within the scope of the present disclosure, including methods having greater than or fewer than the number of steps illustrated, as understood from the discussions herein.

Any additive manufacturing techniques may be used to form the first microtruss panel12and the second microtruss panel18, such as discussed herein.

In some examples, the first truss elements24of the first microtruss structure16are configured such that support structures are not required during the additively manufacturing202of the first microtruss panel12. Herein, support structures refer to structures that support and/or stabilize other portions of an object being additively manufactured. For example, in examples of methods200in which the sandwich panel10includes a first medial skin34, the first medial skin34may be entirely supported by the first truss elements24during the additively manufacturing202of the first microtruss panel12. Additionally or alternatively, a perimeter of the first medial skin34does not extend past a perimeter of the first outer skin14such that the first microtruss structure16acts as a support structure for first medial skin34during the additively manufacturing202. Having the first microtruss panel12fully self-supported during the additively manufacturing202eliminates the need for removing support structures post-manufacturing. Similarly, in some examples, the second truss elements30of the second microtruss structure22are configured such that support structures are not required during the additively manufacturing204of the second microtruss panel18. For example, in examples of methods200in which the sandwich panel10includes a second medial skin38, the second medial skin38may be entirely supported by the second truss elements30during the additively manufacturing204of the second microtruss panel18, thereby eliminating the need for removing support structures post-manufacturing. Additionally or alternatively, a perimeter of the second medial skin38does not extend past a perimeter of the second outer skin20such that second microtruss structure22acts as a support structure for the second medial skin38during the additively manufacturing204.

The coupling206may comprise adhering the damping film26to the first microtruss panel12and to the second microtruss panel18with an adhesive. Alternatively, the damping film26may be held in place between and engaged with the first microtruss panel12and the second microtruss panel18by clamping or otherwise fastening the first microtruss panel12to the second microtruss panel18.

Illustrative, non-exclusive examples of inventive subject matter according to the present disclosure are described in the following enumerated paragraphs:A. A sandwich panel (10), comprising:a first microtruss panel (12) comprising a first outer skin (14) and a first microtruss structure (16) integral with the first outer skin (14), wherein the first microtruss structure (16) comprises first truss elements (24);a second microtruss panel (18) comprising a second outer skin (20) and a second microtruss structure (22) integral with the second outer skin (20), wherein the second microtruss structure (22) comprises second truss elements (30); anda damping film (26) positioned between and engaged with the first microtruss panel (12) and the second microtruss panel (18) opposite the first outer skin (14) and the second outer skin (20).A1. The sandwich panel (10) of paragraph A,wherein the first microtruss structure (16) further comprises first nodes (28) at intersections of two or more first truss elements (24); andwherein the second microtruss structure (22) comprises second nodes (32) at intersections of two or more second truss elements (30).A1.1. The sandwich panel (10) of paragraph A1, wherein the first truss elements (24) and the first outer skin (14) define a plurality of first-microtruss-panel square pyramids (52).A1.2. The sandwich panel (10) of any of paragraphs A1-A1.1, wherein the second truss elements (30) and the second outer skin (20) define a plurality of second-microtruss-panel square pyramids (54).A2. The sandwich panel (10) of any of paragraphs A-A1.2, wherein the first microtruss panel (12) further comprises a first medial skin (34) integral with the first microtruss structure (16) opposite the first outer skin (14).A2.1. The sandwich panel (10) of paragraph A2, wherein at least a subset of the first truss elements (24) terminate at the first medial skin (34).A2.2. The sandwich panel (10) of any of paragraphs A2-A2.1 when depending from paragraph A1, wherein at least a subset of the first nodes (28) coincide with the first medial skin (34).A2.3. The sandwich panel (10) of any of paragraphs A2-A2.2, wherein the first medial skin (34) defines a first-medial-skin lattice structure (36) having a plurality of first-medial-skin voids (35).A3. The sandwich panel (10) of any of paragraphs A-A2.3, wherein the second microtruss panel (18) further comprises a second medial skin (38) integral with the second microtruss structure (22) opposite the second outer skin (20).A3.1. The sandwich panel (10) of paragraph A3, wherein at least a subset of the second truss elements (30) terminate at the second medial skin (38).A3.2. The sandwich panel (10) of any of paragraphs A3-A3.1 when depending from paragraph A1, wherein at least a subset of the second nodes (32) coincide with the second medial skin (38).A3.3. The sandwich panel (10) of any of paragraphs A3-A3.2, wherein the second medial skin (38) defines a second-medial-skin lattice structure (40) having a plurality of second-medial-skin voids (42).A4. The sandwich panel (10) of any of paragraphs A-A3.3, wherein the damping film (26) defines a damping-film lattice structure (44) having a plurality of damping-film voids (46).A4.1. The sandwich panel (10) of paragraph A4 when depending from paragraph A2.3, wherein the damping-film lattice structure (44) coincides with the first-medial-skin lattice structure (36).A4.2. The sandwich panel (10) of any of paragraphs A4-A4.1 when depending from paragraph A3.3, wherein the damping-film lattice structure (44) coincides with the second-medial-skin lattice structure (40).A5. The sandwich panel (10) of any of paragraphs A-A4.2, wherein the damping film (26) is equidistant from the first outer skin (14) and the second outer skin (20).A6. The sandwich panel (10) of any of paragraphs A-A5, wherein the first outer skin (14) and the first microtruss structure (16) of the first microtruss panel (12) are substantially identical with the second outer skin (20) and the second microtruss structure (22) of the second microtruss panel (18).A7. The sandwich panel (10) of any of paragraphs A-A6, wherein the damping film (26) is adhered to the first microtruss panel (12) and to the second microtruss panel (18).A8. The sandwich panel (10) of any of paragraphs A-A7, wherein the damping film (26) is constructed of acrylic tape or synthetic rubber materials.A9. The sandwich panel (10) of any of paragraphs A-A8, wherein the first outer skin (14) comprises a plurality of first-outer-skin ridges (48) extending toward the second microtruss panel (18).A9.1. The sandwich panel (10) of paragraph A9, wherein a subset of the plurality of first-outer-skin ridges (48) extends linearly between intersections of the first truss elements (24) and the first outer skin (14).A10. The sandwich panel (10) of any of paragraphs A-A9.1, wherein the second outer skin (20) comprises a plurality of second-outer-skin ridges (50) extending toward the first microtruss panel (12).A10.1. The sandwich panel (10) of paragraph A10, wherein a subset of the plurality of second-outer-skin ridges (50) extends linearly between intersections of the second truss elements (30) and the second outer skin (20).A11. The sandwich panel (10) of any of paragraphs A-A10.1, wherein the first microtruss panel (12) and the second microtruss panel (18) are constructed of metal.A11.1. The sandwich panel (10) of paragraph A11, wherein the first microtruss panel (12) and the second microtruss panel (18) are constructed of aluminum or an aluminum alloy.A12. The sandwich panel (10) of any of paragraphs A-A11.1, wherein the first microtruss panel (12) comprises one or more first-microtruss-panel mounts (104) for operative coupling of equipment (102) to the sandwich panel (10).A12.1. The sandwich panel (10) of paragraph A12, wherein the one or more first-microtruss-panel mounts (104) are integral with the first outer skin (14).A12.2. The sandwich panel (10) of paragraph A12, wherein the one or more first-microtruss-panel mounts (104) are operatively coupled to the first outer skin (14).A13. The sandwich panel (10) of any of paragraphs A-A12.2, wherein the second microtruss panel (18) comprises one or more second-microtruss-panel mounts (106) for operative coupling of the equipment (102) to the sandwich panel (10).A13.1. The sandwich panel (10) of paragraph A13, wherein the one or more second-microtruss-panel mounts (106) are integral with the second outer skin (20).A13.2. The sandwich panel (10) of paragraph A13, wherein the one or more second-microtruss-panel mounts (106) are operatively coupled to the second outer skin (20).B. A sandwich-panel assembly (100), comprising:the sandwich panel (10) of any of paragraphs A-A11.1; andequipment (102) operatively coupled to the sandwich panel (10).B1. The sandwich-panel assembly (100) of paragraph B, wherein the first microtruss panel (12) comprises one or more first-microtruss-panel mounts (104), and wherein the equipment (102) is operatively mounted to the one or more first-microtruss-panel mounts (104).B1.1. The sandwich-panel assembly (100) of paragraph B1, wherein the one or more first-microtruss-panel mounts (104) are integral with the first outer skin (14).B1.2. The sandwich-panel assembly (100) of paragraph B1, wherein the one or more first-microtruss-panel mounts (104) are operatively coupled to the first outer skin (14).B2. The sandwich-panel assembly (100) of any of paragraphs B-B1.2., wherein the second microtruss panel (18) comprises one or more second-microtruss-panel mounts (106), and wherein the equipment (102) is operatively mounted to the one or more second-microtruss-panel mounts (106).B2.1. The sandwich-panel assembly (100) of paragraph B2, wherein the one or more second-microtruss-panel mounts (106) are integral with the second outer skin (20).B2.2. The sandwich-panel assembly (100) of paragraph B2, wherein the one or more second-microtruss-panel mounts (106) are operatively coupled to the second outer skin (20).B3. The sandwich-panel assembly (100) of any of paragraphs B-B2.2, wherein the equipment (102) is configured to impart a vibration to the sandwich panel (10).B3.1. The sandwich-panel assembly (100) of paragraph B3., wherein the damping film (26) is configured to attenuate vibrations imparted to the sandwich-panel assembly (100) by the equipment (102).C. An apparatus (110), comprising the sandwich-panel assembly (100) of any of paragraphs B-B3.1.D. A method (200) of manufacturing the sandwich panel (10) of any of paragraphs A-A13.2 or the sandwich-panel assembly (100) of any of paragraphs B-B3.1, comprising:additively manufacturing (202) the first microtruss panel (12);additively manufacturing (204) the second microtruss panel (18); andcoupling (206) the damping film (26) between the first microtruss panel (12) and the second microtruss panel (18).E. Use of the sandwich panel (10) of any of paragraphs A-A13.2 to attenuate vibrations from equipment (102) operatively coupled to the sandwich panel (10).

As used herein, the term “and/or” placed between a first entity and a second entity means one of (1) the first entity, (2) the second entity, and (3) the first entity and the second entity. Multiple entries listed with “and/or” should be construed in the same manner, i.e., “one or more” of the entities so conjoined. Other entities optionally may be present other than the entities specifically identified by the “and/or” clause, whether related or unrelated to those entities specifically identified. Thus, as a non-limiting example, a reference to “A and/or B,” when used in conjunction with open-ended language such as “comprising,” may refer, in one example, to A only (optionally including entities other than B); in another example, to B only (optionally including entities other than A); in yet another example, to both A and B (optionally including other entities). These entities may refer to elements, actions, structures, steps, operations, values, and the like.