Abstract: Methods and apparatus for forming a composite structure with a bend in a web and a number of flanges of the composite structure are presented. A flat uncured composite laminate is placed in contact with a forming surface of a mandrel. Pressure is applied to a portion of the flat uncured composite laminate over a kink region in the forming surface of the mandrel to form a bent laminate. The bent laminate and the mandrel are placed into a forming assembly. Overhanging portions of the bent laminate are bent into contact with sides of the mandrel by the forming assembly to form the composite structure, the composite structure having the bend in a web of the composite structure in contact with the forming surface of the mandrel and a number of flanges in contact with the sides of the mandrel.

Abstract: Composite laminate stiffeners such as stringers are punch formed between first and second universal dies respectively carried on first and second trays. The second tray is mounted for sliding movement relative to the first tray between a punch position and a compaction position. Parts of the first and second dies are easily reconfigurable, allowing different shapes of stiffeners to be formed on the same forming apparatus.

Abstract: 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.

Abstract: A tool is configured to form a composite charge into a stringer having a net shape with at least one out-of-place feature. The out-of-plane feature is formed by a shim removably attached to the tool. A family of the shims may be used to form a range of out-of-plane features having varying characteristics.

Abstract: A tool for making contoured composite hat stringers allows control of stringer wrinkling. The tool includes a set of first openings that allow the tool to flex during contouring of the stringer, and a set of second openings into which portions of the composite charge may strain during the contouring.

Abstract: Composite laminate stiffeners such as stringers are punch formed between first and second universal dies respectively carried on first and second trays. The second tray is mounted for sliding movement relative to the first tray between a punch position and a compaction position. Parts of the first and second dies are easily reconfigurable, allowing different shapes of stiffeners to be formed on the same forming apparatus.

Abstract: 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.

Abstract: 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.

Abstract: A tool for making contoured composite hat stringers allows control of stringer wrinkling. The tool includes a set of first openings that allow the tool to flex during contouring of the stringer, and a set of second openings into which portions of the composite charge may strain during the contouring.

Abstract: A tool is configured to form a composite charge into a stringer having a net shape with at least one out-of-place feature. The out-of-plane feature is formed by a shim removably attached to the tool. A family of the shims may be used to form a range of out-of-plane features having varying characteristics.