A blade element is provided and includes courses of bias plies continuously machine-wrapped about leading and trailing edges at an angle relative to a long axis of the blade axis and unidirectional plies interwoven in parallel with the long axis between adjacent courses of the bias plies on upper and lower surfaces to promote respective tangential geometries of the bias plies at the leading and trailing edges, the unidirectional plies not extending into the leading and trailing edges.

A rotor system for a rotary wing aircraft includes a rotor hub including a first beam attachment member and a second beam attachment member. A hub arm including a U-shaped beam member is connected to the rotor hub. The U-shaped beam member includes a first end portion, a second end portion and an intermediate section connecting the first and second end portions. The first end portion is connected at the first beam attachment member. The second end portion is connected at the second beam attachment member. A pitch change bearing is mounted between the first and second beam attachment member through the first end portion and the second end portion.

An assembly system includes a fixture configured to support a structure including at least one component to receive a malleable material, and a bladder system coupled to the fixture. The bladder system includes a hollowed frame having sidewalls that support a bladder disposed therein. The hollowed frame has an opening that exposes an outer portion of the bladder and is configured to guide the exposed outer portion externally from the hollowed frame toward a targeted area of the structure. In response to inflating the bladder, the outer portion of the bladder extends through the opening and applies a force against the at least one component so as to form a design feature element from the malleable material.

A repair patch for a composite edge includes a plurality of laminations laid face-to-face in a lamination direction defined along a thickness direction of the blade edge. At least an uppermost one of the laminations includes first and second transverse peripheral edges and at least the first peripheral edge includes a first portion defining a first edge plane at a first axial location along the second peripheral edge and a second portion defining a second edge plane at a second axial location along the second peripheral edge.

A structure for a trailing edge portion of a rotor blade, wherein the rotor blade has a leading edge, a trailing edge, and opposed upper and lower airfoil profiles each beginning at the leading edge and terminating at the trailing edge. The structure includes an inner core having a generally caret-shaped cross-sectional profile and upper and lower skins adhered to the inner core. The upper and lower skins have respective first and second portions adhered to the inner core, and respective third portions which are adhered to each other and which extend aftward to proximate the trailing edge. An upper pocket is defined by the second and third upper skin portions and the upper airfoil profile, and a lower pocket is defined by the second and third lower skin portions and the lower airfoil profile. The upper and lower pockets are filled with a fairing compound and/or an expandable adhesive.

A method of mounting a replacement tip section to an exposed end of a rotor blade includes removing an existing tip section from the rotor blade to create the exposed end of the rotor blade, installing the rotor blade having the exposed end onto a holding fixture, assembling the replacement tip section about the exposed end of the rotor blade, positioning a bonding fixture about the replacement tip section, and curing the replacement tip section to the exposed end of the rotor blade.

A bond fixture includes a frame that defines a chamber for receiving a component. At least one bladder assembly is mounted to the frame and extends into the chamber to apply a pressure to an adjacent surface of the component. A caul assembly is positionable about the component and receivable within the chamber. The caul assembly heats a localized portion of the component.

A method for separating a first mechanical part from a second mechanical part is described, wherein the second mechanical part is bonded to the first mechanical part by an adhesive film along a connecting area, the first mechanical part having a first specific thermal conductivity and the second mechanical part having a second thermal conductivity that is higher than the first thermal conductivity. The method includes at least one cooling step during which the second mechanical part is cooled to a negative temperature and at least one stressing step during which the second mechanical part is subjected to mechanical stress in order to cause the adhesive film to break.

A method for separating a first mechanical part from a second mechanical part is described, wherein the second mechanical part is bonded to the first mechanical part by an adhesive film along a connecting area, the first mechanical part having a first specific thermal conductivity and the second mechanical part having a second thermal conductivity that is higher than the first thermal conductivity. The method includes at least one cooling step during which the second mechanical part is cooled to a negative temperature and at least one stressing step during which the second mechanical part is subjected to mechanical stress in order to cause the adhesive film to break.

A three-dimensional auxetic structure, comprising a plurality of adjoining hollow cells, each hollow cell having cell walls and a transversal cross section of the plurality hollow cells following a two-dimensional auxetic pattern, each cell wall comprising folding lines parallel to a plane containing the auxetic pattern such that peaks and valleys are defined in the cell walls and the cell walls being foldable along the folding lines.