Additively manufactured aerospace panels and methods
An aerospace panel includes a first skin, a second skin spaced apart from the first skin, and a first truss structure connecting the first skin to the second skin. The first truss structure includes a plurality of truss members. Each truss member is integral with the first skin and the second skin, such that the first skin, the second skin, and the first truss structure collectively form a single monolithic joint-free structure. At least one of the skins also includes at least one lattice region that includes a lattice grid and an array of openings.
1 . An aerospace panel, comprising:
a first skin;
a second skin spaced apart from the first skin; and
a truss structure connecting the first skin to the second skin, the truss structure includes a plurality of truss members, and the truss members extend between first nodes on the first skin and second nodes on the second skin and are integral with the first skin and the second skin, such that the first skin, the second skin, and the truss structure collectively form a single monolithic joint-free structure,
wherein at least a portion of the first skin is formed by a first open lattice comprising a grid of first lattice strips that extend between at least a portion of the first nodes.
2 . The aerospace panel of claim 1 , further comprising:
a grid of first stiffeners protruding from the first skin, each of the first stiffeners is associated with a first stiffener reference plane,
wherein:
the first nodes are positioned at first intersections of the first stiffeners; and
the first lattice strips are aligned with at least a portion of the first stiffeners, each the first lattice strips is associated with a first skin reference plane that is not coincident with the first stiffener reference plane.
3 . The aerospace panel of claim 2 , wherein:
the second skin has a grid of second stiffeners;
the second nodes are defined at second intersections of the second grid of stiffeners;
the first stiffeners define one or more first grid units;
the second stiffeners define one or more second grid units; and
the first grid units are offset from the second grid units in a manner such that when the aerospace panel is viewed along a direction normal to the first skin, each one of the first nodes is aligned with a geometric center of one of the second grid units.
4 . The aerospace panel of claim 1 , wherein at least one of the first skin and the second skin stiffeners is non-planar.
5 . The aerospace panel of claim 1 , further comprising a closeout wall extending between the first skin and the second skin along at least one edge of the aerospace panel,
wherein the first skin, the second skin, the truss structure, and the closeout wall collectively form the single monolithic joint-free structure.
6 . The aerospace panel of claim 1 , wherein:
the plurality of truss members comprises a plurality of X-shaped truss members; and
each one of the X-shaped truss members extends between a pair of the first nodes on the first skin and a pair of the second nodes on the second skin.
7 . The aerospace panel of claim 1 , wherein:
the plurality of truss members forms an array of core structures; and
a density of the core structures varies over at least one region of the aerospace panel.
8 . The aerospace panel of claim 1 , further comprising:
a third skin spaced apart from the second skin; and
a second truss structure connecting the second skin to the third skin,
wherein the first skin, the second skin, the third skin, the truss structure, and the second truss structure collectively form the single monolithic joint-free structure.
9 . The aerospace panel of claim 1 , wherein:
the aerospace panel has:
a primary axis parallel to a lengthwise direction of the first skin and the second skin; and
a secondary axis perpendicular to the primary axis and normal to the first skin and the second skin;
each truss member is oriented at a first truss angle of approximately 35 degrees to approximately 50 degrees relative to the secondary axis when the aerospace panel is viewed along a direction perpendicular to both the primary axis and the secondary axis; and
each truss member is oriented at a second truss angle of approximately 35 degrees to approximately 50 degrees relative to the secondary axis when the aerospace panel is viewed along the primary axis.
10 . The aerospace panel of claim 1 , wherein at least one of the first skin and the second skin has an internal channel embedded respectively in the first skin and/or the second skin.
11 . The aerospace panel of claim 1 , wherein at least a portion of the second skin is formed by a second open lattice comprising a grid of second lattice strips that extend between at least a portion of the second nodes.
12 . An aerospace vehicle, comprising:
a body having one or more aerospace panels, each of the aerospace panels comprising:
a first skin;
a second skin spaced apart from the first skin; and
a truss structure connecting the first skin to the second skin, the truss structure includes a plurality of truss members, and the truss members extend between first nodes on the first skin and second nodes on the second skin and are integral with the first skin and the second skin, such that the first skin, the second skin, and the first truss structure collectively form a single monolithic joint-free structure,
wherein at least a portion of the first skin is formed by a first open lattice comprising a grid of first lattice strips that extend between at least a portion of the first nodes.
13 . A method for manufacturing an aerospace panel, the method comprising:
printing a first skin and a second skin spaced apart from the first skin, while simultaneously printing a plurality of truss members of a first truss structure connecting the first skin to the second skin, thereby resulting in a single monolithic joint-free structure,
wherein:
the truss members extend between first nodes on the first skin and second nodes on the second skin; and
at least a portion of the first skin is formed by a first open lattice comprising a grid of first lattice strips that extend between at least a portion of the first nodes.
14 . The method of claim 13 , wherein:
printing the first skin comprises:
printing a grid of first stiffeners, each of the first stiffeners is associated with a first stiffener reference plane; and
printing the first lattice strips to be aligned with at least a portion of the first stiffeners, each of the first lattice strips is associated with a first skin reference plane that is not coincident with the first stiffener reference plane;
printing the second skin comprises printing a grid of second stiffeners; and
printing the plurality of truss members comprises printing the truss member to extend between the first nodes, defined at first intersections of the first stiffeners, and the second nodes, defined at second intersections of the second stiffeners.
15 . The method of claim 14 , wherein:
printing the first stiffeners and printing the second stiffeners respectively comprise:
printing the first stiffeners to form one or more first grid units; and
printing the second stiffeners to form one or more second grid units; and
the first grid units are offset from the second grid units in a manner such that when the aerospace panel is viewed along a direction normal to the first skin, each one of the first nodes is aligned with a geometric center of one of the second grid units.
16 . The method of claim 13 , further comprising:
printing a closeout wall while printing the first skin, the second skin, and the truss structure,
wherein the closeout wall extends between the first skin and the second skin along at least one edge of the aerospace panel.
17 . The method of claim 13 , wherein:
printing the plurality of truss members comprises printing a plurality of X-shaped truss members; and
each one of the X-shaped truss members extends between a pair of the first nodes on the first skin and a pair of the second nodes on the second skin.
18 . The method of claim 13 , wherein printing the plurality of truss members comprises printing the plurality of truss members as an array of core structures that vary in density over at least one region of the aerospace panel.
19 . The method of claim 13 , further comprising printing a third skin spaced apart from the second skin, and a second truss structure connecting the second skin to the third skin, while printing the first skin, the second skin, and the truss structure.
20 . The method of claim 13 , wherein:
the aerospace panel has:
a primary axis parallel to a lengthwise direction of the first skin and the second skin; and
a secondary axis perpendicular to the primary axis and normal to the first skin and the second skin; and
printing the plurality of truss members comprises printing each truss member at a first truss angle of 35-50 degrees relative to the secondary axis, when the aerospace panel is viewed along a direction perpendicular to both the primary axis and the secondary axis, and at a second truss angle of 35-50 degrees relative to the secondary axis, when the aerospace panel is viewed along the primary axis.