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: A method of fabricating a plank stringer for use in an aircraft includes grouping a plurality of stacked plies of reinforcing material into a plurality of charges, where each charge in the plurality of charges includes a substack of plies. The method also includes grouping the plurality of charges into two or more groups such that, for each charge in a given group, a respective substack of plies includes a sequence of orientation angles with respect to a longitudinal axis of the plank stringer corresponding to the given group. The method also includes laying up each group of charges as a continuous blanket of plies, where each continuous blanket of plies includes the respective substack of plies for each charge in the respective group. The method also includes cutting each continuous blanket of plies into the respective group of charges and stacking the plurality of charges to form the plank stringer.

Abstract: A solid laminate stringer includes a base segment that forms a first generally trapezoidal cross section. The solid laminate stringer also includes a transition segment abutting the base segment, with concave sides that are continuous with the sides of the base segment. The solid laminate stringer also includes a top segment abutting the transition segment, where the top segment forms a second generally trapezoidal cross section with sides that are continuous with the concave sides of the transition segment. The solid laminate stringer may also include a first overwrap layer covering the top segment, the transition segment, and at least a portion of the base segment. The solid laminate stringer may also include a second overwrap layer overlapping at least a portion of the first overwrap layer covering the base segment.

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 solid laminate stringer includes a base segment that forms a first generally trapezoidal cross section. The solid laminate stringer also includes a transition segment abutting the base segment, with concave sides that are continuous with the sides of the base segment. The solid laminate stringer also includes a top segment abutting the transition segment, where the top segment forms a second generally trapezoidal cross section with sides that are continuous with the concave sides of the transition segment. The solid laminate stringer may also include a first overwrap layer covering the top segment, the transition segment, and at least a portion of the base segment. The solid laminate stringer may also include a second overwrap layer overlapping at least a portion of the first overwrap layer covering the base segment.

Abstract: A solid laminate stringer includes a base segment that forms a first generally trapezoidal cross section. The solid laminate stringer also includes a transition segment abutting the base segment, with concave sides that are continuous with the sides of the base segment. The solid laminate stringer also includes a top segment abutting the transition segment, where the top segment forms a second generally trapezoidal cross section with sides that are continuous with the concave sides of the transition segment. The solid laminate stringer also includes a first overwrap layer covering the top segment, the transition segment, and at least a portion of the base segment. The solid laminate stringer also includes a second overwrap layer overlapping at least a portion of the first overwrap layer covering the base segment.

Abstract: A method of fabricating a plank stringer for use in an aircraft includes grouping a plurality of stacked plies of reinforcing material into a plurality of charges, where each charge in the plurality of charges includes a substack of plies. The method also includes grouping the plurality of charges into two or more groups such that, for each charge in a given group, a respective substack of plies includes a sequence of orientation angles with respect to a longitudinal axis of the plank stringer corresponding to the given group. The method also includes laying up each group of charges as a continuous blanket of plies, where each continuous blanket of plies includes the respective substack of plies for each charge in the respective group. The method also includes cutting each continuous blanket of plies into the respective group of charges and stacking the plurality of charges to form the plank 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 a detection layer connected to the outer surface, the detection layer being discontinuous and including glass fibers embedded in a matrix material.

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: A solid laminate stringer includes a base segment that forms a first generally trapezoidal cross section. The solid laminate stringer also includes a transition segment abutting the base segment, with concave sides that are continuous with the sides of the base segment. The solid laminate stringer also includes a top segment abutting the transition segment, where the top segment forms a second generally trapezoidal cross section with sides that are continuous with the concave sides of the transition segment. The solid laminate stringer also includes a first overwrap layer covering the top segment, the transition segment, and at least a portion of the base segment. The solid laminate stringer also includes a second overwrap layer overlapping at least a portion of the first overwrap layer covering the base segment.

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 a detection layer connected to the outer surface, the detection layer being discontinuous and including glass fibers embedded in a matrix material.

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 a detection layer connected to the outer surface, the detection layer being discontinuous and including glass fibers embedded in a matrix material.