A method and device for protecting an adjacent rupturable component including positioning a sheet of puncture resistant, flexible material including one or more openings at or about the structure opening wherein the one or more openings accommodate the rupturable component; permanently or semi-permanently attaching the sheet to the structure at a first portion of an area of the sheet; and positioning the rupturable component through the one or more openings, such that one or more portions of the rupturable component near the one or more openings are protected by the sheet if the structure becomes frayed; wherein the sheet prevents damage to the rupturable component if the structure frays or fractures at or about the structure opening.

A wide-body aircraft is disclosed with a fuselage section that includes a set of side-by-side fuselage lobes having a fuselage skin. A first woven composite preform positioned at a first intersection of the set of side-by-side fuselage lobes located at a first cusp of the side-by-side fuselage lobes. A second woven composite preform positioned at a second intersection of the set of side-by-side fuselage lobes located at a second cusp of the side-by-side fuselage lobes. Each of the first and second woven composite preforms are configured to receive a structural component, such that each of the first and second woven composite preforms accommodates vertical load imparted through the structural component.

Cap wrinkling in a contoured composite hat stringer is reduced by constraining the cap as the hat stringer is being formed from a flat composite charge. The cap is constrained by an inflatable bladder placed in a tool set used to form the composite charge.

A system and method for welding thermoplastic components by positioning and moving a heated plate between the components to melt their respective faying surfaces, and as the plate moves, pressing the components together so that the melted faying surfaces bond together as they cool and re-solidify, thereby creating a composite structure. The plate has a heated portion which is positioned between and heated to melt a portion of the first and second faying surfaces. A manipulator mechanism moves the plate along an interface from between the portion to between a series of subsequent portions of the first and second faying surfaces, thereby welding the thermoplastic components along the entire interface to create the composite structure. The heated portion may contact the faying surfaces and melt them through conduction, or may be suspended between them and melt them through radiation and convection.

In an example, a composite stringer is described. The composite stringer includes a skin flange having a first gage, a top flange having a second gage, and a web having a third gage and extending between the skin flange and the top flange. The skin flange is configured to be coupled to a support structure. The support structure includes at least one of a skin of a vehicle or a base charge. The second gage of the top flange is greater than the first gage of the skin flange and the third gage of the web. The skin flange, the top flange, and the web include a plurality of plies of composite material.

In an example, a composite stringer assembly includes a composite stringer, a radius filler, and an overwrap layer. The composite stringer includes: (i) a skin flange configured to be coupled to a support structure, (ii) a web, (iii) a lower corner portion of the composite stringer extending from the skin flange to the web, and (iv) an inner surface of the composite stringer extending along the skin flange, the lower corner portion, and the web. The radius filler includes a first surface coupled to the inner surface at the lower corner portion, a second surface configured to couple to the support structure, and a third surface extending between the first surface and the second surface. The overwrap layer is coupled to the inner surface at the web, the third surface of the radius filler, and the support structure.

A method of joining a first workpiece to a second workpiece is disclosed including securing a spark containment cap to the first workpiece, the cap comprising an electrically insulating washer and a cap body defining an air cavity. Once the cap has been secured, a tail of a fastener is inserted into the air cavity through the second workpiece, the first workpiece and the washer. Upon tightening the fastener, the tail of the fastener urges the washer against the first workpiece and the first and second workpiece are thereby clamped between the washer and a head of the fastener so as to form a joint. Advantageously, it has been found that forming a joint in this manner can help to better protect the joint from the effects of electrical arcing.

Disclosed herein is a composition and a method for energy harvesting and the autonomous detection of structural failure. This method can be used to monitor, for example, the structural integrity of unmanned aircraft systems.

An aircraft fuselage includes an element forming a skin and a load-carrying structure supporting the element forming the skin. The load-carrying structure includes a plurality of elements forming a spar disposed parallel to an axial direction defined by the fuselage and a plurality of elements forming a frame disposed spaced apart along the axial direction. Each element forming a frame being arranged substantially perpendicularly to the elements forming a spar, where the element forming the skin is fastened on an external perimeter of each element forming a frame by means of fastening elements configured to keep the element forming the skin away from the external perimeter and where the element forming the skin is made of a transparent material.

Described herein are methods and systems for forming composite stringer assemblies or, more specifically, for shaping composite charges while forming these stringer assemblies. A system comprises a bladder, having a bladder core, and a bladder skin. The bladder core is formed from foam. The bladder skin is formed from an elastic material and encloses the bladder core. When a composite stringer assembly is formed, the bladder is positioned over a charge base. The charge base later becomes a stringer base, such as a fuselage section or a wing skin. A charge hat is then positioned over the bladder and is conformed to the bladder. A combination of the bladder skin and the bladder core provides support during this forming operation and later while the stringer assembly is cured. In some examples, the bladder core is collapsible for the removal of the bladder from the cavity of the stringer assembly.