Abstract:
A composite pressure vessel assembly method includes fitting an end portion of a tubular member into an annular slot formed in an end cap. Sealant may be in the annular slot. The end cap includes an annular groove in an exterior surface of the end cap body portion. A first material layer is formed on an exterior surface of the tubular member. The first material layer includes a first composite material including fibers oriented circumferentially to the tubular member. A second material layer is formed on the first material layer with a portion of the second material layer being disposed into the annular groove, and includes a second composite material including fibers oriented axially to the tubular member. A third material layer is formed adjacent the second material layer and in the annular groove, and includes a third composite material including fibers having an orientation circumferential to the tubular member.
Abstract:
A composite pressure vessel assembly method includes fitting an end portion of a tubular member into an annular slot formed in an end cap. Sealant may be in the annular slot. The end cap includes an annular groove in an exterior surface of the end cap body portion. A first material layer is formed on an exterior surface of the tubular member. The first material layer includes a first composite material including fibers oriented circumferentially to the tubular member. A second material layer is formed on the first material layer with a portion of the second material layer being disposed into the annular groove, and includes a second composite material including fibers oriented axially to the tubular member. A third material layer is formed adjacent the second material layer and in the annular groove, and includes a third composite material including fibers having an orientation circumferential to the tubular member.
Abstract:
Negative Poisson's ratio (NPR) or auxetic are used to make lightweight wheels and runflat tires. The NPR tires can be tailored and functionally-designed to optimally meet the runflat requirements for both military and commercial vehicles. NPR-runflat tires may be fabricated using standard materials and simple manufacturing processes, resulting in low-cost and high-volume production. In preferred embodiments the runflat tire designs are fully compatible with Central Tire Inflation Systems (CTIS), while providing a performance equivalent to current military vehicle solutions but at half the weight. An auxetic wheel according to the invention comprises a line defining an axis of rotation; and a plurality of concentric rings of unit cells surrounding the axis, each unit cell being constructed of a plurality of members defining a Negative Poisson's Ratio (NPR) structure. The outermost ring of unit cells is arranged to facilitate rolling terrain contact, such that the stiffness of the structure in the localized region of loading due to terrain contact increases as the wheel rotates. A layer of material may be disposed between the concentric rings of unit cells which in preferred embodiments comprise a plurality of nested-V shapes. A cover may be provided over the outermost ring of unit cells forming a tire which may, or may not, be inflated.
Abstract:
Negative Poisson's ratio (NPR) or auxetic are used to make lightweight wheels and runflat tires. The NPR tires can be tailored and functionally-designed to optimally meet the runflat requirements for both military and commercial vehicles. NPR-runflat tires may be fabricated using standard materials and simple manufacturing processes, resulting in low-cost and high-volume production. In preferred embodiments the runflat tire designs are fully compatible with Central Tire Inflation Systems (CTIS), while providing a performance equivalent to current military vehicle solutions but at half the weight. An auxetic wheel according to the invention comprises a line defining an axis of rotation; and a plurality of concentric rings of unit cells surrounding the axis, each unit cell being constructed of a plurality of members defining a Negative Poisson's Ratio (NPR) structure. The outermost ring of unit cells is arranged to facilitate rolling terrain contact, such that the stiffness of the structure in the localized region of loading due to terrain contact increases as the wheel rotates. A layer of material may be disposed between the concentric rings of unit cells which in preferred embodiments comprise a plurality of nested-V shapes. A cover may be provided over the outermost ring of unit cells forming a tire which may, or may not, be inflated.