Abstract: A method of incremental autofrettage is taught herein, whereby the cycle life of a metal liner in a pressure vessel is increased. This method serves to increase the yield strength of the metal liner through sequential work hardening due to repeated autofrettage at increasing pressures. By incrementally increasing the internal pressure used in the autofrettage process, the compressive stresses at an inner surface of the metal liner may be controlled so that post-pressurization buckling does not occur, yet the yield strength of the metal liner is substantially increased. The higher compressive stresses in the metal liner mean that higher Maximum Expected Operating Pressures (MEOPs) may be used without detracting from the cycle life of the metal liner, or alternatively, for lower pressures, a longer metal liner cycle life may be obtained. Either internal or external pressures may be used, generated by a pressure source, or a suitable die.

Abstract: A method of incremental autofrettage is taught herein, whereby the cycle life of a metal liner in a pressure vessel is increased. This method serves to increase the yield strength of the metal liner through sequential work hardening due to repeated autofrettage at increasing pressures. By incrementally increasing the internal pressure used in the autofrettage process, the compressive stresses at an inner surface of the metal liner may be controlled so that post-pressurization buckling does not occur, yet the yield strength of the metal liner is substantially increased. The higher compressive stresses in the metal liner mean that higher Maximum Expected Operating Pressures (MEOPs) may be used without detracting from the cycle life of the metal liner, or alternatively, for lower pressures, a longer metal liner cycle life may be obtained. Either internal or external pressures may be used, generated by a pressure source, or a suitable die.

Abstract: A boom section includes a first, a second, a third, and a fourth fiber reinforced thermoset composite material layer and a flex core layer. The first fiber reinforced thermoset composite material layer has glass fibers in a vinyl ester matrix. The second fiber reinforced thermoset composite material layer is disposed over the first composite material layer and has carbon fibers in an epoxy matrix. The flex core layer is disposed over the second composite material layer. The third fiber reinforced thermoset composite material layer is disposed over the flex core layer and has aramid fibers in a vinyl ester matrix. The fourth fiber reinforced thermoset composite material layer is disposed over the third composite material layer and has glass fibers in a vinyl ester matrix.

Abstract: The present invention relates to a lightweight boss system for use on a tank or pressure vessel. The boss system is preferably made of a composite or resin transfer molded (RTM) material. It is particularly useful for composite tanks, such as filament-wound composite tanks.

Abstract: The present invention is a boom system comprising a first boom section having a distal end and a proximal end. A second boom section includes a distal end and a proximal end, wherein the proximal end of the second boom section is rotatably coupled to the distal end of the first boom section. At least one of the boom sections is substantially formed from composite materials.

Abstract: The present invention is a boom system comprising a first boom section having a distal end and a proximal end. A second boom section includes a distal end and a proximal end, wherein the proximal end of the second boom section is rotatably coupled to the distal end of the first boom section. At least one of the boom sections is substantially formed from composite materials.

Abstract: The present invention is a boom system comprising a plurality of articulated boom sections. Each boom section has a longitudinal axis. A stiffening layer is attached to a surface of at least one of the boom sections, and extends within about ten degrees of parallel to the longitudinal axis of the boom section. The stiffening layer is formed of a fiber-reinforced composite material including a plurality of fibers and matrix material.

Abstract: A robotic positioning device has a support structure and a tool implement holding member which is positional within the three dimensional space of the support structure. The tool implement holding member is connected to the support structure utilizing five positioning members. Each of these positioning members is connected to the tool implement holding member. Three of the positioning members are connected to the holding member at a first common center of rotation and the other two positioning members are connected to the holding member at a second common center of rotation. Each of the positioning members is attached to the support structure utilizing a connecting member which allows for the positioning member to freely pivot with respect to the support structure and additionally allows the member to move with respect to the support structure axially along an axis of the member. This is accomplished by moving the members axially toward or away from the support structure.

Abstract: A filament wound pressure vessel is disclosed and has a generally spherical portion including a polar opening defined by a fitting. A composite comprising a plurality of layers of filaments forms part of the thickness of the vessel, with the layers of filaments wound about the fitting. The fitting comprises a polar boss having a stepped configuration of decreasing diameters in a direction outwardly of the vessel, whereby sequential layers of filaments lay against sequentially smaller diameters of the fitting. The polar boss may comprise part of a liner for the vessel about which the layers of filaments are wound.

Abstract: A filament wound pressure vessel is disclosed and has a spherical shape including a polar opening with a fitting disposed in the opening and protruding therefrom. A plurality of layers of filaments are wound about the polar fitting. Each layer comprises a sequence of polar winding patterns wound with incrementally increasing wind angles away from the polar fitting, creating voids at the junctures of adjacent patterns near the polar fitting and thus between sequential layers at said junctures. One or more annular fill doilies are installed in annular regions about the polar fitting to fill the voids between the layers at the junctures of adjacent winding patterns. The doilies are circular in configuration with a central opening for installation concentric with the polar opening.