Abstract: Examples for low impact hat stringer fluid dams are presented herein. An aircraft structure may include a wing with a vent stringer coupled to the wing. The vent stringer may include a center portion positioned between a first section and a second section. The center portion of the vent stringer includes a slot. A vent dam may be coupled within the vent stringer proximate the slot in the center portion. The vent dam can include a sealant coupled between an integrated pair of baffles such that a combination of the sealant and the integrated pair of baffles prevents fluid communication between the first section and the second section of the vent stringer.

Abstract: Examples for low impact hat stringer fluid dams are presented herein. An aircraft structure may include a wing with a vent stringer coupled to the wing. The vent stringer may include a center portion positioned between a first section and a second section. The center portion of the vent stringer includes a slot. A vent dam may be coupled within the vent stringer proximate the slot in the center portion. The vent dam can include a sealant coupled between an integrated pair of baffles such that a combination of the sealant and the integrated pair of baffles prevents fluid communication between the first section and the second section of the vent stringer.

Abstract: A hat-stringer assembly for an aircraft comprises a hat stringer with a first hat-stringer leg, a second hat-stringer leg, a first hat-stringer sidewall, a connecting wall, a second hat-stringer sidewall, and a ventilation opening, extending through the connecting wall. The hat stringer assembly also comprises a fitting, comprising a first channel member in contact with the first hat-stringer sidewall and the first hat-stringer leg. The fitting also comprises a second channel member in contact with the second hat-stringer sidewall and the second hat-stringer leg. The fitting further comprises a web cap, in contact with the first channel member and the second channel member. The web cap comprises a web-cap opening, which is in fluidic communication with the ventilation opening.

Abstract: A vented hat stringer for an aircraft comprises a first hat-stringer leg with a first-hat-stringer-leg surface, a second hat-stringer leg with a second-hat-stringer-leg surface, a first hat-stringer sidewall, a second hat-stringer sidewall, and a hat-stringer connecting wall, comprising a hat-stringer-connecting-wall surface and a virtual hat-stringer-connecting-wall symmetry plane, passing through hat-stringer connecting wall. The vented hat stringer further comprises a ventilation opening, extending through at least one of the first hat-stringer sidewall or the hat-stringer connecting wall, or extending through at least one of the second hat-stringer sidewall or the hat-stringer connecting wall. The ventilation opening defines a ventilation-opening centerline, wherein the ventilation-opening centerline does not coincide with the virtual hat-stringer-connecting-wall symmetry plane.

Abstract: A vented hat stringer for an aircraft comprises a first hat-stringer leg with a first-hat-stringer-leg surface, a second hat-stringer leg with a second-hat-stringer-leg surface, a first hat-stringer sidewall, a second hat-stringer sidewall, and a hat-stringer connecting wall, comprising a hat-stringer-connecting-wall surface and a virtual hat-stringer-connecting-wall symmetry plane, passing through hat-stringer connecting wall. The vented hat stringer further comprises a ventilation opening, extending through at least one of the first hat-stringer sidewall or the hat-stringer connecting wall, or extending through at least one of the second hat-stringer sidewall (116) or the hat-stringer connecting wall. The ventilation opening defines a ventilation-opening centerline, wherein the ventilation-opening centerline does not coincide with the virtual hat-stringer-connecting-wall symmetry plane.

Abstract: A hat-stringer assembly (100) for an aircraft (500) comprises a hat stringer (110) with a first hat-stringer leg (140), a second hat-stringer leg (150), a first hat-stringer sidewall (114), a connecting wall (112), a second hat-stringer sidewall (116), and a ventilation opening (128), extending through the connecting wall (112). The hat stringer assembly (100) also comprises a fitting (200), comprising a first channel member (210) in contact with the first hat-stringer sidewall (114) and the first hat-stringer leg (140). The fitting (200) also comprises a second channel member (240) in contact with the second hat-stringer sidewall (116) and the second hat-stringer leg (150). The fitting (200) further comprises a web cap (260), in contact with the first channel member (210) and the second channel member (240). The web cap (260) comprises a web-cap opening (262), which is in fluidic communication with the ventilation opening (128).

Abstract: A composite structure including a composite body having an outer surface, wherein the composite body is elongated along a span axis, and a detection layer connected to the outer surface of the composite body, the detection layer including a plurality of strips, wherein each strip comprises a plurality of glass fibers embedded in a matrix material, is elongated along a detection axis, the detection axis being substantially aligned with the span axis, and is spaced a non-zero distance apart from adjacent strips such that a discontinuity is defined between adjacent strips.

Abstract: An apparatus is provided for forming a pleat of a vacuum bag into position over a stringer of an uncured skin panel. The apparatus comprises a leading shoe and a trailing shoe that cooperates with the leading shoe to form the pleat of the vacuum bag. The apparatus also comprises at least one roller assembly for compacting the formed pleat into position over the stringer.

Abstract: Examples for low impact hat stringer fluid dams are presented herein. An aircraft structure may include a wing with a vent stringer coupled to the wing. The vent stringer may include a center portion positioned between a first section and a second section. The center portion of the vent stringer includes a slot. A vent dam may be coupled within the vent stringer proximate the slot in the center portion. The vent dam can include a sealant coupled between an integrated pair of baffles such that a combination of the sealant and the integrated pair of baffles prevents fluid communication between the first section and the second section of the vent stringer.

Abstract: An example method for forming a flat composite charge into a composite blade stiffener includes cutting a flat composite charge along a cut line into a first piece and a second piece having an angle, positioning the first piece and the second piece of the flat composite charge on a forming mandrel about a tooling plunger, activating the tooling plunger to drive the first piece and the second piece into a cavity of the forming mandrel resulting in the first piece and the second piece folding at the cut line, withdrawing the tooling plunger from the cavity of the forming mandrel, compressing the forming mandrel to apply a lateral pressure to the first piece and the second piece folded into the cavity, and applying a vertical pressure to a first flange and a second flange of the first piece and the second piece, respectively, to form the composite blade stiffener.

Abstract: The construction of a stringer transition through a common base eliminates the need for plate fittings and their associated fasteners to connect opposing ends of a first stringer having a large cross-sectional area to a second stringer having a smaller cross-sectional area. A base of composite material is secured to a skin panel of an aircraft wing with the base aligned with and extending along the longitudinal length of the skin panel. The first stringer is secured to the base and the second stringer is secured to the base, with the first stringer and second stringer longitudinally aligned with the base and with a longitudinal spacing between the first stringer and the second stringer. The base connects the first stringer to the second stringer and only the base connects the first stringer to the second stringer.

Abstract: An example method for forming a flat composite charge into a composite blade stiffener includes cutting a flat composite charge along a cut line into a first piece and a second piece having an angle, positioning the first piece and the second piece of the flat composite charge on a forming mandrel about a tooling plunger, activating the tooling plunger to drive the first piece and the second piece into a cavity of the forming mandrel resulting in the first piece and the second piece folding at the cut line, withdrawing the tooling plunger from the cavity of the forming mandrel, compressing the forming mandrel to apply a lateral pressure to the first piece and the second piece folded into the cavity, and applying a vertical pressure to a first flange and a second flange of the first piece and the second piece, respectively, to form the composite blade stiffener.

Abstract: An apparatus is provided for forming a pleat of a vacuum bag into position over a stringer of an uncured skin panel. The apparatus comprises a leading shoe and a trailing shoe that cooperates with the leading shoe to form the pleat of the vacuum bag. The apparatus also comprises at least one roller assembly for compacting the formed pleat into position over the stringer.

Abstract: The construction of a stringer transition through a common base eliminates the need for plate fittings and their associated fasteners to connect opposing ends of a first stringer having a large cross-sectional area to a second stringer having a smaller cross-sectional area. A base of composite material is secured to a skin panel of an aircraft wing with the base aligned with and extending along the longitudinal length of the skin panel. The first stringer is secured to the base and the second stringer is secured to the base, with the first stringer and second stringer longitudinally aligned with the base and with a longitudinal spacing between the first stringer and the second stringer. The base connects the first stringer to the second stringer and only the base connects the first stringer to the second stringer.

Abstract: An example method for forming a flat composite charge into a composite blade stiffener includes cutting a flat composite charge along a cut line into a first piece and a second piece having an angle, positioning the first piece and the second piece of the flat composite charge on a forming mandrel about a tooling plunger, activating the tooling plunger to drive the first piece and the second piece into a cavity of the forming mandrel resulting in the first piece and the second piece folding at the cut line, withdrawing the tooling plunger from the cavity of the forming mandrel, compressing the forming mandrel to apply a lateral pressure to the first piece and the second piece folded into the cavity, and applying a vertical pressure to a first flange and a second flange of the first piece and the second piece, respectively, to form the composite blade stiffener.

Abstract: A composite structure including a composite body having an outer surface and including a web portion having a proximal portion and a distal portion, and a base portion connected to the proximal portion of the web portion, wherein the composite body is elongated along a span axis, and a detection layer connected to the outer surface of the composite body at the distal portion of the web portion of the composite body, the detection layer including a plurality of glass fibers embedded in a first matrix material, wherein the composite body includes a plurality of carbon fibers embedded in a second matrix material, and wherein the outer surface of the composite body subjacent the detection layer is substantially free of exposed carbon fibers of the plurality of carbon fibers.

Abstract: A composite structure including a composite body having an outer surface, wherein the composite body is elongated along a span axis, and a detection layer connected to the outer surface of the composite body, the detection layer including a plurality of strips, wherein each strip comprises a plurality of glass fibers embedded in a matrix material, is elongated along a detection axis, the detection axis being substantially aligned with the span axis, and is spaced a non-zero distance apart from adjacent strips such that a discontinuity is defined between adjacent strips.

Abstract: An apparatus for forming a material layer onto a form tool may include at least one nosepiece configured to laterally sweep a ply carrier onto a form tool contour. The apparatus may include a pair of tension arms configured to support opposing lateral sides of a ply carrier having a material layer mounted to a lower surface thereof. The apparatus may include one or more actuators configured to position the tension arms during forming of the ply carrier to the form tool contour. The one or more actuators may be configured to sense and control lateral tension in the ply carrier during forming of the ply carrier to the form tool contour.

Abstract: An example method for forming a flat composite charge into a composite blade stiffener includes cutting a flat composite charge along a cut line into a first piece and a second piece having an angle, positioning the first piece and the second piece of the flat composite charge on a forming mandrel about a tooling plunger, activating the tooling plunger to drive the first piece and the second piece into a cavity of the forming mandrel resulting in the first piece and the second piece folding at the cut line, withdrawing the tooling plunger from the cavity of the forming mandrel, compressing the forming mandrel to apply a lateral pressure to the first piece and the second piece folded into the cavity, and applying a vertical pressure to a first flange and a second flange of the first piece and the second piece, respectively, to form the composite blade stiffener.

Abstract: A substantially rigid batten is attached to an external face of a vacuum bag to reduce wrinkling of the bag during vacuum bag compaction of a composite laminate layup.