Abstract: Square symmetric composite laminate structures, and sub-modules thereof, are provided, along with methods of forming the same. The square symmetric laminate structures include two or more sub-laminate modules, each comprising: a first ply set consisting of a first ply layer oriented at a first angle and a second ply layer oriented at a second angle, a first sum of the first and second angles being ninety degrees; and a second ply set consisting of a third ply layer oriented at a third angle and a fourth ply layer oriented at a fourth angle, a second sum of the third and fourth angles being ninety degrees; wherein the second ply layer is positioned adjacent the third ply layer and the second and third ply layers are both positioned intermediate the first and fourth ply layers, thereby defining a double-double helix arrangement of the respective ply layers. Associated methods are also provided.

Abstract: A sub-laminate module is described for use in forming composite laminate structures. The module includes a first ply set containing a first ply layer oriented at a first angle and a second ply layer oriented at a second angle, the second angle being unequal the first angle; a second ply set containing a third ply layer oriented at a third angle and a fourth ply layer oriented at a fourth angle, the fourth angle being unequal the third angle; first and second equal acute angles are defined by differences between an absolute value of the first and second angles and the third and fourth angles, respectively, wherein the second ply layer is positioned adjacent the third ply layer and the second and third ply layers are both positioned intermediate the first and fourth ply layers, so as to define a staggered double-double helix sequence of the respective ply layers. Associated composite laminate structures and methods are also disclosed.

Abstract: An octogrid structure and method of forming the same for a composite laminate structure is provided. The octogrid sub-structure comprises: a first ply layer comprising a plurality of first elongate tapes oriented in a first direction and a plurality of second elongate tapes oriented in a second direction; and a second ply layer comprising a plurality of third elongate tapes oriented in the first direction and a plurality of fourth elongate tapes oriented in the second direction, the second ply layer being overlaid atop the first ply layer. A first end of each of the elongate tapes is positioned approximately adjacent a midpoint of an adjacently positioned one of the elongate tapes; and a second and opposing end of each of elongate tapes extends freely beyond a central grid portion defined by a length of a portion between the first end and the midpoint of the elongate tapes.

Abstract: A grid and skin assembly for use in a composite laminate structure is described. The assembly includes a metallic grid having a plurality of intersecting ribs oriented in at least two distinct rib directions offset at a grid angle relative to one another and defining respective intersection points; and a composite laminate skin having a plurality of ply layers comprising a plurality of tapes oriented in at least two distinct tape directions offset at a ply angle relative to one another. The grid angle is at least 25 degrees, the intersection points define glueless joints of the metallic grid, and the grid is a non-aluminum-based material. A grid and method of manufacturing the grid and skin assembly is also described. The method includes a water jet cutting procedure and glueless joint formation due to differing thermal expansion characteristics of the grid and skin.

Abstract: Described are various dual-tapered composite laminate structures. These structures may comprise a plurality of finite sub-laminate cards, each one of the plurality of cards having the same shape and size as the other ones of the plurality of cards and having opposing surfaces oriented in a card plane, opposing primary edges of the planar surfaces, and opposing secondary edges of the planar surfaces, the opposing secondary edges being perpendicular to the opposing primary edges. The finite sub-laminate cards are tacked relative to one another in a successively offset manner. Also described are methods of stacking and sliding (for offset) the finite sub-laminate cards. Tapered fuselage skin and fuel tank covers are also considered.

Abstract: Square symmetric composite laminate structures, and sub-modules thereof, are provided, along with methods of forming the same. The square symmetric laminate structures include two or more sub-laminate modules, each comprising: a first ply set consisting of a first ply layer oriented at a first angle and a second ply layer oriented at a second angle, a first sum of the first and second angles being ninety degrees; and a second ply set consisting of a third ply layer oriented at a third angle and a fourth ply layer oriented at a fourth angle, a second sum of the third and fourth angles being ninety degrees; wherein the second ply layer is positioned adjacent the third ply layer and the second and third ply layers are both positioned intermediate the first and fourth ply layers, thereby defining a double-double helix arrangement of the respective ply layers. Associated methods are also provided.

Abstract: An octogrid structure and method of forming the same for a composite laminate structure is provided. The octogrid sub-structure comprises: a first ply layer comprising a plurality of first elongate tapes oriented in a first direction and a plurality of second elongate tapes oriented in a second direction; and a second ply layer comprising a plurality of third elongate tapes oriented in the first direction and a plurality of fourth elongate tapes oriented in the second direction, the second ply layer being overlaid atop the first ply layer. A first end of each of the elongate tapes is positioned approximately adjacent a midpoint of an adjacently positioned one of the elongate tapes; and a second and opposing end of each of elongate tapes extends freely beyond a central grid portion defined by a length of a portion between the first end and the midpoint of the elongate tapes.

Abstract: A sub-laminate module is described for use in forming composite laminate structures. The module includes a first ply set containing a first ply layer oriented at a first angle and a second ply layer oriented at a second angle, the second angle being unequal the first angle; a second ply set containing a third ply layer oriented at a third angle and a fourth ply layer oriented at a fourth angle, the fourth angle being unequal the third angle; first and second equal acute angles are defined by differences between an absolute value of the first and second angles and the third and fourth angles, respectively, wherein the second ply layer is positioned adjacent the third ply layer and the second and third ply layers are both positioned intermediate the first and fourth ply layers, so as to define a staggered double-double helix sequence of the respective ply layers. Associated composite laminate structures and methods are also disclosed.

Abstract: Disclosed is a sub-laminate module for use in forming a composite laminate structure. The sub-laminate module comprises: a first ply set containing a first ply layer oriented at a first angle and a second ply layer oriented at a second angle, the second angle being equal and opposite the first angle; a second ply set containing a third ply layer oriented at a third angle and a fourth ply layer oriented at a fourth angle, the fourth angle being equal and opposite the third angle; and an acute angle defined by a difference between the first angle and the third angle, wherein the second ply layer is positioned adjacent the third ply layer and the second and third ply layers are both positioned intermediate the first and fourth ply layers, so as to define a double-double helix arrangement. Associated composite laminate structures and methods are also disclosed.

Abstract: Described are composite grid structures that have a plurality of ply layers, each one of the plurality of ply layers comprising a plurality of first elongate tapes oriented in a first direction and a plurality of second elongate tapes oriented in a second direction, the second direction being offset from the first direction by an angle of at least 25 degrees. In the grid structures: each of the first elongate tapes has a first length extending between opposing ends of each of the plurality of first elongate tapes and a first midpoint intermediate the opposing ends, and each of the second elongate tapes has a second length extending between opposing ends of each of the plurality of second elongate tapes and a second midpoint intermediate the opposing ends. Associated composite laminate structures, grid structures, and methods of manufacturing and/or using the same are also disclosed.

Abstract: Disclosed is a sub-laminate module for use in forming a composite laminate structure. The sub-laminate module comprises: a first ply set containing a first ply layer oriented at a first angle and a second ply layer oriented at a second angle, the second angle being equal and opposite the first angle; a second ply set containing a third ply layer oriented at a third angle and a fourth ply layer oriented at a fourth angle, the fourth angle being equal and opposite the third angle; and an acute angle defined by a difference between the first angle and the third angle, wherein the second ply layer is positioned adjacent the third ply layer and the second and third ply layers are both positioned intermediate the first and fourth ply layers, so as to define a double-double helix arrangement. Associated composite laminate structures and methods are also disclosed.

Abstract: Variously configured sub-laminate modules are provided, which comprise at least a first ply and a second ply, the first ply comprising fibers extending in a first orientation, the second ply comprising fibers extending in a second orientation. The second orientation is offset relative to the first orientation, which offset defines an acute angle between the two orientations. The acute angle is less than 90 degrees and in at least one embodiment, the acute angle is approximately 25°. In certain embodiments, the acute angle further defines an unbalanced structure of the sub-laminate module. In certain embodiments, the first and second plies may be further secured relative to one another in a non-crimped configuration. Composite laminated structures formed from various embodiments of the sub-laminate modules are also provided, at least some of which may be homogenized. Various methods of manufacturing the sub-laminate modules and the composite laminated structures are also provided.

Abstract: Variously configured sub-laminate modules are provided, which comprise at least a first ply and a second ply, the first ply comprising fibers extending in a first orientation, the second ply comprising fibers extending in a second orientation. The second orientation is offset relative to the first orientation, which offset defines an acute angle between the two orientations. The acute angle is less than 90 degrees and in at least one embodiment, the acute angle is approximately 25°. In certain embodiments, the acute angle further defines an unbalanced structure of the sub-laminate module. In certain embodiments, the first and second plies may be further secured relative to one another in a non-crimped configuration. Composite laminated structures formed from various embodiments of the sub-laminate modules are also provided, at least some of which may be homogenized. Various methods of manufacturing the sub-laminate modules and the composite laminated structures are also provided.

Abstract: A fiber composite tape has a first two-layer strip having a first top layer with fibers angled at ? and a first bottom layer with fibers angled at 0, a second two-layer strip having a second top (or bottom) layer with fibers angled at ?? and a second bottom (or top) layer with fibers angled at 0, and a paper backing tape affixed to the two two-layer strips and joins them side-by-side at their edges to form a seam.

Abstract: Various embodiments provide a bi-angle pliable tape for use in forming a composite laminate structure. The bi-angle pliable tape comprises: a longitudinal axis extending in a unidirectional machine direction; a first ply comprising fibers extending in a first orientation, the first orientation being offset relative to the longitudinal axis at a first angle of less than 30°; and a second ply comprising fibers extending in a second orientation, the second orientation being opposite the first orientation relative to the unidirectional machine direction. The first ply and the second ply are further secured substantially adjacently relative to one another by one or more yarns so as to provide a non-crimped configuration such that the bi-angle tape defines a pliable structure. Corresponding composite laminate structures and methods for making the same are provided.

Abstract: A fiber composite tape has a first two-layer strip having a first top layer with fibers angled at ? and a first bottom layer with fibers angled at 0, a second two-layer strip having a second top (or bottom) layer with fibers angled at ?? and a second bottom (or top) layer with fibers angled at 0, and a paper backing tape affixed to the two two-layer strips and joins them side-by-side at their edges to form a seam.

Abstract: A flywheel for use as an energy storage device is made of hoops of different fiber composite layers, the radial thickness of each hoop and the physical properties of the fiber composite in each loop being chosen by a computer modeling optimization procedure to maximize total energy of storage while minimizing radial stress.

Abstract: A flywheel for use as an energy storage device is made of hoops of different fiber composite layers, the radial thickness of each hoop and the physical properties of the fiber composite in each loop being chosen by a computer modeling optimization procedure to maximize total energy of storage while minimizing radial stress.

Abstract: Composite grid/frame structures are constructed from grid elements 36 arranged in a grid pattern and bonded together by a vacuum infiltration technique or, alternatively, a filament winding technique. Grid elements 36 are sliced cross-sections of pultruded or filament-wound tubing typically made from glass or graphite fiber and epoxy resin. Common cross-sectional shapes are square, rectangular, triangular, and circular. Finished two-dimensional grids 46 may be combined with longitudinal rods 48 to form three-dimensional frames for concrete reinforcement, engine containment, and many other applications.