Method of forming a contoured hat stiffener
AssigneeThe Boeing Company
InventorsMichael Robert Chapman, Gordon Dale Davis
Life of this patent
Estimating the term…
Abstract
A flexible punch and die are used to form a flat composite laminate charge into a stiffener having a desired cross sectional shape. A desired contour is formed in the stiffener by bending the punch and die. Ply wrinkling is avoided during contouring by maintaining those portions of the stiffener subject to wrinkling in tension as the contouring is being performed. Bridging of the plies during the contouring process is avoided by first contouring those sections of the stiffener that are subject to wrinkling, and then contouring the remaining sections of the stiffener.
Claims13
A method of forming a contoured hat-shaped composite stiffener, comprising:
- placing a composite charge that is generally flat on a die having a die cavity, wherein the composite charge rests on top of a pressure plate that is supported by a piston rod, wherein the piston rod is directly connected to a cylinder;
- driving the composite charge into the die cavity with a punch to form a hat-shaped stiffener, comprising a cap, a pair of flanges, and a pair of webs connecting the pair of flanges to the cap;
- placing a portion of the hat-shaped stiffener in tension by compressing the cap between the pressure plate and the punch, wherein a first surface of the cap contacts the pressure plate and a second surface of the cap contacts the punch, wherein a neutral axis of the hat-shaped stiffener shifts away from the pressure plate;
- and
- forming a contour along a longitudinal axis in the hat-shaped stiffener while the cap is compressed between the pressure plate and the punch to form the contoured hat-shaped composite stiffener.
A method of forming a hat-shaped composite stiffener contoured along its length, comprising:
- placing a composite charge that is generally flat on a die, wherein the composite charge rests on top of a pressure plate that is supported by a piston rod, wherein the piston rod is directly connected to a cylinder;
- punch forming the composite charge between the die and a punch into the hat-shaped composite stiffener, wherein the hat-shaped composite comprises, a cap, a pair of flanges, and a pair of webs connecting the pair of flanges to the cap;
- placing a portion of the hat-shaped composite stiffener in tension by compressing the cap between the pressure plate and the punch, wherein a first surface of the cap contacts the pressure plate and a second surface of the cap contacts the punch, wherein a neutral axis of the hat-shaped composite stiffener shifts away from the pressure plate;
- and
- stiffener;
- and
- forming a contour along a longitudinal axis in the hat-shaped composite stiffener, while the cap is compressed, by first forming a portion of the contour in an intermediate section of the hat-shaped composite stiffener and then forming other portions of the contour on opposite sides of the intermediate section.
A method of forming a contoured hat-shaped composite stiffener, comprising:
- placing a composite charge that is generally flat on a die having a die cavity, wherein the composite charge rests on top of a pressure plate that is supported by a piston rod, wherein the piston rod is directly connected to a cylinder;
- forming a hat-shaped stiffener using a punch to drive the composite charge into the die cavity, wherein the hat-shaped stiffener comprises a cap, a pair of flanges, and a pair of webs connecting the cap with the pair of flanges;
- placing a portion of the hat-shaped stiffener in tension by compressing the pair of flanges using a pair of pressure plates connected to pneumatic cylinders;
- and
- forming a contour along a longitudinal axis in the hat-shaped stiffener while the portion of the hat-shaped stiffener is being held in tension.
Dependencies are inferred from the claim text.