Punch forming composite charge

Abstract

To provide punch forming a composite charge.SOLUTION: A method of punch forming a composite charge is presented. A forming tool is placed in contact with the composite charge. A plurality of actuators connected to the forming tool is simultaneously activated to drive the forming tool toward the composite charge. The actuators are driven at a plurality of rates to generate a variable cross-section in the composite charge. The actuators are simultaneously stopped.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] FIELD OF THE DISCLOSURE The present disclosure relates generally to composite manufacturing, and more particularly to methods for forming composite structures having variable cross-sections. [Background technology]

[0002] Historically, composite stringers for commercial aircraft applications have been designed with a constant cross-section along the wingspan. Constant cross-section composite stringers can be made using conventional methods of punch forming.

[0003] Future aircraft designs can benefit from tapered stringer cross-sections, which can reduce stringer weight and / or improve performance. However, conventional methods of composite stringer punch forming do not account for cross-sectional taper. Summary of the Invention [Problem to be solved by the invention]

[0004] It would therefore be desirable to have a method and apparatus that takes into account at least some of the problems noted above, as well as other potential problems. For example, it would be desirable to have a punch forming method that can produce tapered cross sections. [Means for solving the problem]

[0005] One embodiment of the present disclosure provides a method for punch forming a composite charge. A forming tool is placed in contact with the composite charge. Multiple actuators connected to the forming tool are simultaneously activated to drive the forming tool toward the composite charge. The multiple actuators are driven at multiple speeds to generate variable cross-sections within the composite charge. The multiple actuators are simultaneously deactivated.

[0006] One embodiment of the present disclosure provides a punch forming system for a variable cross-section. The punch forming system includes a charge support, a forming tool, and a plurality of actuators. The charge support is configured to support a composite charge during formation of the composite charge, the forming tool is disposed on the charge support, the forming tool has a forming surface and a back surface, and the plurality of actuators are connected to the back surface of the forming tool and configured to operate at a plurality of speeds to form the composite charge between the forming surface and the charge support.

[0007] Yet another embodiment of the present disclosure provides a method of punch forming a composite charge.

[0008] A composite charge is placed on the charge support, and a forming tool is driven relative to the composite charge toward the charge support using multiple actuators at multiple speeds to generate variable cross-sections in the composite charge, the multiple actuators stopping simultaneously.

[0009] Yet another embodiment of the present disclosure provides a method of punch forming a composite charge. A forming tool is placed in contact with the composite charge. Multiple actuators connected to the forming tool are simultaneously actuated to drive the forming tool toward the composite charge. The multiple actuators are actuated at multiple stroke lengths to generate variable cross-sections within the composite charge. The multiple actuators are simultaneously deactivated.

[0010] The features and functions can be achieved alone in various embodiments of the present disclosure and may be combined in still other embodiments, further details of which can be seen with reference to the following description and drawings.

[0011] The novel features believed characteristic of the illustrative embodiments are set forth in the appended claims. However, the illustrative embodiments, together with their preferred modes of use, further objects and features, will best be understood by reference to the following detailed description of illustrative embodiments of the present disclosure when read in conjunction with the accompanying drawings. [Brief explanation of the drawings]

[0012] [Figure 1] 1 is an illustration of an aircraft in accordance with an illustrative embodiment; [Figure 2] FIG. 1 is an illustration of a block diagram of a manufacturing environment in accordance with an illustrative embodiment. [Figure 3] FIG. 1 is an isometric view of a longitudinal component that may be manufactured using punch forming, according to an exemplary embodiment. [Figure 4] FIG. 1 is a schematic side view of a forming tool and multiple actuators for forming a punch, according to an exemplary embodiment; [Figure 5] FIG. 1 is a schematic side view of a forming tool and multiple actuators for forming a punch, according to an exemplary embodiment; [Figure 6] 10A-10C are schematic side views of a forming tool relative to a charge support before and after punch forming in accordance with an exemplary embodiment; [Figure 7] FIG. 1 is a schematic front view of a forming tool and charge support prior to punch formation in accordance with an exemplary embodiment; [Figure 8A] 1 is a flowchart of a method for punch forming a composite charge in accordance with an exemplary embodiment. [Figure 8B] 1 is a flowchart of a method for punch forming a composite charge in accordance with an exemplary embodiment. [Figure 9] 1 is a flowchart of a method for punch forming a composite charge in accordance with an exemplary embodiment. [Figure 10] 1 is a flowchart of a method for punch forming a composite charge in accordance with an exemplary embodiment. [Figure 11] FIG. 1 is an illustration of an aircraft manufacturing and service method in the form of a block diagram in accordance with an illustrative embodiment; [Figure 12] FIG. 1 is an illustration of an aircraft in the form of a block diagram in which an illustrative embodiment may be implemented; DETAILED DESCRIPTION OF THE INVENTION

[0013] The illustrative examples recognize and take into account several considerations: The illustrative embodiments recognize and take into account that volumetric changes in the stringer cross section can cause excess material along the length of the part, inducing wrinkles and other misalignments; The illustrative examples recognize and take into account excess material along tapered geometries; The illustrative examples provide novel approaches to accounting for excess material to improve part manufacturability.

[0014] The illustrative examples recognize and take into account that conventional methods of punch forming for stringers have a constant speed of forming for a constant cross section. The illustrative examples recognize and take into account that conventional methods of punch forming have a constant speed so that the material begins and ends the forming cycle simultaneously. The illustrative examples recognize and take into account that the constant speed provides a uniform constraint to the layup to control part quality.

[0015] To create a tapered cross-section, the illustrative example provides a forming routine that compensates for geometric variations along the length. The illustrative example compensates for geometric variations by forming at a variable rate so that the part begins and finishes forming simultaneously. The illustrative example provides a constant cross-section and the same uniform constraint throughout the forming cycle.

[0016] An illustrative example forms material at a variable rate such that the material is constrained throughout the forming process. An illustrative example provides an instrument that operates in a manner that provides variable speed. An illustrative example provides motion control and programming capabilities for the instrument. An illustrative example provides an instrument with variable speed forming capabilities. In an illustrative example, each actuator positioned longitudinally along the forming mold can punch a different cross-sectional size than an adjacent cross-section in the same time span as the adjacent cross-section. An illustrative example utilizes a tapered forming mold.

[0017] Turning now to Figure 1 , an illustration of an aircraft is depicted in accordance with an illustrative embodiment. Aircraft 100 has wing 102 and wing 104 attached to fuselage 106. Aircraft 100 includes engine 108 attached to wing 102 and engine 110 attached to wing 104.

[0018] The fuselage 106 has a tail section 112. A horizontal stabilizer 114, a horizontal stabilizer 116, and a vertical stabilizer 118 are attached to the tail section 112 of the fuselage 106.

[0019] Aircraft 100 is an example of an aircraft that may have composite parts manufactured using the illustrative example punch forming methods and / or punch forming systems. Composite parts of at least one of wing 102, wing 104, or fuselage 106 may be formed using the illustrative example punch forming methods and / or punch forming systems. For example, stringers of at least one of wing 102, wing 104, and fuselage 106 may be formed using the illustrative example punch forming methods and / or punch forming systems.

[0020] Turning now to Figure 2, a block diagram of a manufacturing environment is depicted in accordance with an illustrative embodiment. A punch forming system 201 can be used to punch a composite charge 246 to form a variable cross section 254.

[0021] The punch forming system 201 for variable cross-section 254 includes a charge support 284, a forming tool 202, and a plurality of actuators 204. The charge support 284 is configured to support the composite charge 246 during formation of the composite charge 246. The forming tool 202 is disposed on the charge support 284. In some illustrative examples, the forming tool 202 may be referred to as elongated 242. The forming tool 202 includes a forming surface 208 and a back surface 206. The plurality of actuators 204 are coupled to the back surface 206 of the forming tool 202 and configured to operate at a plurality of speeds 210 to form the composite charge 246 between the forming surface 208 and the charge support 284. During forming, the plurality of actuators 204 move at the multiple speeds 210 such that forming is completed simultaneously.

[0022] The plurality of actuators 204 spans the back surface 206 of the forming tool 202 along a longitudinal axis 244 of the forming tool 202. The longitudinal axis 244 extends from the first end 232 to the second end 234 of the forming tool 202. In some illustrative examples, the plurality of actuators 204 is arranged in a row on the back surface 206 of the forming tool 202. The plurality of actuators 204 is arranged such that each actuator of the plurality of actuators 204 moves a respective portion of the forming tool 202. The plurality of actuators 204 may comprise any desired number of actuators. In this illustrative example, the plurality of actuators 204 comprises actuator 212, actuator 216, actuator 220, actuator 224, and actuator 228.

[0023] As shown, actuator 228 is closest to first end 232 of forming tool 202. As shown, actuator 212 is closest to second end 234 of forming tool 202. Actuator 224, actuator 220, and actuator 216 extend between actuator 228 and actuator 212. Each actuator of plurality of actuators 204 has a respective speed of multiple speeds 210. Actuator 212 operates at speed 214, actuator 216 operates at speed 218, actuator 220 operates at speed 222, actuator 224 operates at speed 226, and actuator 228 operates at speed 230. Each of multiple speeds 210 of multiple actuators 204 is independently set based on a variable cross-section 254 formed in composite charge 246.

[0024] Speed ​​230 is different from speed 214. In some illustrative examples, speed 230 is faster than speed 214. In some illustrative examples, speed 214 is faster than speed 230. When the cross-section of forming tool 202 at first end 232 is wider than the cross-section at second end 234, speed 230 is faster than speed 214. In some illustrative examples, the actuators between actuator 228 and actuator 212 have any range of speeds. In some illustrative examples, speed 226, speed 222, and speed 218 are within a range between speed 214 and speed 230.

[0025] To form the composite charge 246, multiple actuators 204 connected to the forming tool 202 are simultaneously actuated to drive the forming tool 202 toward the composite charge 246. The multiple actuators 204 are actuated at multiple speeds 210 to create a variable cross-section 254 in the composite charge 246. The multiple actuators 204 are simultaneously deactivated. The multiple speeds 210 are affected by a curvature 238 of the forming surface 208. The curvature 238 is configured to create the variable cross-section 254 in the composite charge 246.

[0026] The plurality of actuators 204 are distributed along a longitudinal axis 244 of the forming tool 202. Actuating the plurality of actuators 204 at a plurality of speeds 210 to create a variable cross-section 254 in the composite charge 246 includes actuating the plurality of actuators 204 at a plurality of stroke lengths 211 along the longitudinal axis 244 to create the variable cross-section 254 in the composite charge 246. The plurality of actuators 204 are actuated at a plurality of stroke lengths 211 to create the variable cross-section 254 in the composite charge 246. The plurality of stroke lengths 211 cause one end of the forming surface 208 to move farther than another end of the forming surface 208.

[0027] Actuating the multiple actuators 204 at the multiple stroke lengths 211 forms the composite charge 246 into a shape having a first height 272 at the first end 268 and a second height 276 at the second end 270. The second height 276 is different from the first height 272. When the second height 276 is greater than the first height 272, the stroke length 213 of the actuator 212 is greater than the stroke length 229 of the actuator 228. When the second height 276 is greater than the first height 272, the second end 234 moves farther than the first end 232.

[0028] In some illustrative examples, the plurality of actuators 204 may include actuators of different lengths, in these illustrative examples, the plurality of actuators 204 may be fully retracted before initiating punch formation.

[0029] In other illustrative examples, the plurality of actuators 204 can include a single length actuator, with each actuator extending a different distance prior to forming the composite charge 246. In these illustrative examples, the plurality of actuators 204 are initially extended to a plurality of different lengths. In these illustrative examples, some of the plurality of actuators 204 are partially extended prior to initiating punch formation.

[0030] To punch-form composite charge 246, forming tool 202 is placed in contact with composite charge 246. In some illustrative examples, placing forming tool 202 in contact with composite charge 246 includes placing forming tool 202 in contact with length 258, which is the overall length of composite charge 246. In some illustrative examples, forming tool 202 contacts a centerline of composite charge 246. In some illustrative examples, forming tool 202 contacts a region of composite charge 246 that will form a cap region of stringer 252.

[0031] Multiple actuators 204 connected to the forming tool 202 are actuated simultaneously to drive the forming tool 202 in a forming direction 245 toward the composite charge 246. The multiple actuators 204 are actuated at multiple speeds 210 to create variable cross-sections 254 within the composite charge 246. The multiple actuators 204 are deactuated simultaneously.

[0032] In some illustrative examples, actuating the plurality of actuators 204 at the plurality of speeds 210 to generate the variable cross-section 254 in the composite charge 246 includes forming the composite charge 246 into a shape having a first height 272 at the first end 268 and a second height 276 at the second end 270. The second height 276 is different from the first height 272. When the second height 276 is higher than the first height 272, the speed 214 of the actuators 212 is faster than the speed 230 of the actuators 228. When the second height 276 is higher than the first height 272, the second end 234 moves faster than the first end 232.

[0033] In some illustrative examples, actuating the plurality of actuators 204 at the plurality of speeds 210 to generate the variable cross-section 254 in the composite charge 246 includes forming the composite charge 246 into a shape having a first width 274 at the first end 268 and a second width 278 at the second end 270, where the second width 278 is different from the first width 274. In some illustrative examples, the variable cross-section 254 is symmetrical.

[0034] In some illustrative examples, forming the variable cross-section 254 includes at least partially restraining a portion of the composite charge 246 to maintain tension 260 in the composite charge 246 while driving the plurality of actuators 204.

[0035] Actuating the plurality of actuators 204 at multiple speeds 210 to generate the variable cross-section 254 in the composite charge 246 includes rotating the forming tool 202 about a rotational axis 240 that is parallel to the width 256 of the composite charge 246. Actuating the plurality of actuators 204 at multiple speeds 210 to generate the variable cross-section 254 causes the forming tool 202 to pivot 243 about the rotational axis 240. In some illustrative examples, as the forming tool 202 pivots 243, the first end 232 moves farther than the second end 234. In these illustrative examples, pivoting the forming tool 202 about the rotational axis 240 causes the first end 232 to move faster than the second end 234 of the forming tool 202 in the forming direction 245. In some illustrative examples, the second end 234 moves farther than the first end 232 as the forming tool pivots 243. In these illustrative examples, pivoting forming tool 202 about rotation axis 240 causes second end 234 to move faster than first end 232 of forming tool 202 in forming direction 245. Pivoting forming tool 202 during formation of composite charge 246 reduces wrinkling during formation. Rotation axis 240 is perpendicular to both longitudinal axis 244 of forming tool 202 and forming direction 245 of movement of forming tool 202.

[0036] In some illustrative examples, charge support 284 includes a gap 289 for forming composite charge 246. In some illustrative examples, gap 289 is a set size. In some illustrative examples, charge support 284 is fixed. In other illustrative examples, gap 289 of charge support 284 is adjustable.

[0037] In some illustrative examples, charge support 284 comprises a first half 286 and a second half 290 with a gap 288 between first half 286 and second half 290. In some illustrative examples, charge support 284 comprises first half 286 and second half 290, and at least one of first half 286 and second half 290 is configured to move away from the other of first half 286 and second half 290 to enable formation of composite charge 246.

[0038] In some illustrative examples, the punch forming system 201 includes a translation system 292 connected to the charge support 284 and enabling translation of at least one of the first half 286 and the second half 290 in multiple axes. The translation system 292 can take any desired form. In some illustrative examples, the translation system 292 can include one of bearings, wheels, rails, or any other desired translation components. In some illustrative examples, the translation system 292 enables translation along a first axis 294 to enable the first half 286 and the second half 290 to move away from each other. In some illustrative examples, the translation system 292 enables translation along a second axis 296 to enable different distances between the first half 286 and the second half 290 at different positions along the longitudinal axis 244 of the forming tool 202. In some illustrative examples, the translation system 292 enables the first half 286 and the second half 290 to “fan” relative to each other.

[0039] In some illustrative examples, the punch forming system 201 includes a clamping system 282 that compresses the portion 248 of the composite charge 246 against the portion 236 of the forming tool 202 during formation of the composite charge 246. In some illustrative examples, the clamping system 282 constrains the composite charge 246 to a cap region. In some illustrative examples, the portion 248 is a centerline of the composite charge 246. In some illustrative examples, a clamping force 283 is applied to compress the portion 248 of the composite charge 246 against the forming tool 202 before actuating the plurality of actuators 204 prior to forming the variable cross-section 254.

[0040] In some illustrative examples, the punch forming system 201 includes a composite charge restraint 280 that maintains tension 260 in the composite charge 246 during formation of the composite charge 246 by applying pressure 281 against the composite charge 246 and toward one of the forming tool 202 and the charge support 284. The composite charge restraint 280 may take any desired form. In some illustrative examples, the composite charge restraint 280 takes the form of at least one of a clamp and an inflatable bladder.

[0041] Composite charge 246 having variable cross section 254 may be referred to as longitudinal component 250. In some illustrative examples, longitudinal component 250 takes the form of stringer 252.

[0042] In some illustrative examples, composite charge 246 is trimmed 266 after forming variable cross-section 254. In some of these illustrative examples, composite charge 246 may be rectangular 262 when composite charge 246 is placed on charge support 284.

[0043] In some illustrative examples, the composite charge 246 is in net shape 264 before forming. In these illustrative examples, the composite charge 246 is not trimmed 266 after forming the variable cross-section 254. The composite charge 246 may be laid up to the net shape 264 or trimmed 266 to the net shape 264 before placing the composite charge 246 on the charge support 284.

[0044] The illustration of manufacturing environment 200 in FIG. 2 is not meant to imply physical or architectural limitations to the manner in which an illustrative embodiment may be implemented. Other components in addition to or in place of the illustrated components may be used. Some components may be unnecessary. Additionally, the blocks are presented to illustrate some functional components. One or more of these blocks may be combined, divided, or combined and divided into different blocks when implemented in an illustrative embodiment.

[0045] For example, in some illustrative examples, the plurality of actuators 204 includes more than five actuators. In some illustrative examples, the forming tool 202 may be segmented. In some illustrative examples, the forming tool 202 includes multiple segments, each segment connected to a respective actuator of the plurality of actuators 204.

[0046] Attention now turns to FIG. 3 , which depicts an isometric view of a longitudinal component that may be manufactured using punch forming, according to an illustrative embodiment. Longitudinal component 301 is a physical implementation of longitudinal component 250 formed from composite charge 246 of FIG. 2 . In this illustrative example, longitudinal component 301 takes the form of a hat-shaped stringer. Variable cross-section 302 of longitudinal component 301 may be formed using punch forming system 201 of FIG. 2 .

[0047] Variable cross-section 302 has a first end 304 and a second end 306. First end 304 has a first height 308 and a first width 309. Second end 306 has a second height 310 and a second width (not shown). In this illustrative example, first height 308 and second height 310 are different. In some illustrative examples, first width 309 and second width are different. In this illustrative example, second height 310 is greater than first height 308.

[0048] Attention now turns to FIG. 4 , which depicts a schematic side view of a forming tool and multiple actuators for punch forming, according to an exemplary embodiment. A forming tool 404 of a punch forming system is shown in view 400. The forming tool 404 is a physical implementation of the forming tool 202 of FIG. 2 . The multiple actuators 402 are a physical implementation of the multiple actuators 204 of FIG. 2 . The forming tool 404 can be used to form a composite charge into a longitudinal component 301 having a variable cross-section 302.

[0049] Forming tool 404 has a back surface 406 and a forming surface 408. The plurality of actuators 402 is coupled to the back surface 406 of forming tool 404. In this illustrative example, the plurality of actuators 402 comprises ten actuators. The plurality of actuators 402 may comprise any desired number of actuators.

[0050] In this illustrative example, actuator 410 is disposed furthest at first end 418 of forming tool 404. In this illustrative example, actuator 412 is disposed furthest at second end 420. In some illustrative examples, actuator 410 may be referred to as the first actuator and actuator 412 may be referred to as the last actuator.

[0051] In this illustrative example, at first end 418, back surface 406 is spaced a first distance 414 from forming surface 408. In this illustrative example, at second end 420, back surface 406 is spaced a second distance 416 from forming surface 408. The difference in thickness of forming tool 404 from first end 418 to second end 420 creates a variable cross-section in the composite charge during punch formation.

[0052] In view 400, the forming tool 404 is positioned in a first orientation 401. The first orientation 401 can be an orientation for the forming tool 404 prior to punch forming the composite charge. In the first orientation 401, the forming surface 408 is positioned such that a portion of the forming surface 408 contacts a portion of the composite charge. In the first orientation 401, the forming surface 408 is positioned to contact the composite charge along the entire length of the composite charge. In view 400, the plurality of actuators 402 are positioned such that the forming surface 408 is held in a substantially flat position. In view 400, the plurality of actuators 402 are initially extended to a plurality of different lengths. In view 400, some of the plurality of actuators 402 are partially extended prior to initiating punch forming. To form the composite charge, the forming tool 404 is moved in a direction 422. The direction 422 is toward the composite charge.

[0053] Attention now turns to FIG. 5 , which depicts a schematic side view of a forming tool and multiple actuators for punch forming, according to an illustrative embodiment. In view 500, the forming tool 404 is in a second orientation 501. In some illustrative examples, the second orientation 501 is the orientation of the forming tool 404 after punching a composite charge. Between the first orientation 401 and the second orientation 501, the multiple actuators 402 move at multiple speeds. In view 400, the multiple actuators 402 are extended multiple distances. Between view 400 and view 500, the multiple actuators 402 are extended multiple stroke lengths. In view 500, the multiple actuators 402 are extended by the same amount. Between view 400 and view 500, the multiple actuators 402 started and stopped moving simultaneously. Between view 400 and view 500, actuator 412 moved faster than actuator 410.

[0054] Between view 400 and view 500, forming tool 404 is pivoted in direction 502. By pivoting forming tool 404 in direction 502, second end 420 moves further than first end 418 in direction 422. By pivoting forming tool 404 in direction 502, second end 420 moves faster than first end 418 of forming tool 404. Pivoting forming tool 404 during formation of the composite charge reduces wrinkling during formation.

[0055] In this illustrative example, forming tool 404 is pivoted in direction 502 about axis of rotation 504. Axis of rotation 504 extends into and out of the page. Axis of rotation 504 is perpendicular to both the longitudinal axis of forming tool 404 and the direction of movement 422 of forming tool 404.

[0056] In this illustrative example, the actuators 402 have the same length. In other non-depicted examples, the actuators 402 can have different lengths. In some illustrative examples, each of the actuators 402 having different lengths is fully retracted in view 400 and each of the actuators 402 is fully extended in view 500.

[0057] Attention now turns to Figure 6, which depicts a schematic side view of a forming tool relative to a charge support before and after punch forming, according to an exemplary embodiment. Forming tool 602 and charge support 604 may be physical implementations of forming tool 202 and charge support 284 of Figure 2. Forming tool 602 and charge support 604 may be used to form longitudinal component 301 of Figure 3. Forming tool 602 may be the same as forming tool 404 of Figures 4 and 5.

[0058] In view 600, the forming tool 602 is depicted in a first orientation 606 and a second orientation 608 relative to the charge support 604. In the first orientation 606, the forming tool 602 is prepared to begin forming a composite charge on the charge support 604. In the first orientation 606, the forming tool 602 is depicted raised above the charge support 604. Prior to beginning formation of the composite charge, the forming tool 602 is moved in a direction 610 to place the forming tool 602 in contact with the composite charge in the first orientation 606. In this illustrative example, the forming tool 602 is positioned such that the forming surface 618 presents a substantial flatness in the first orientation 606. In the first orientation 606, the forming surface 618 of the forming tool 602 is parallel to the composite charge. In the first orientation 606, the distance from the forming surface 618 of the forming tool 602 to the charge support 604 is the same distance along the longitudinal axis of the charge support 604. In first orientation 606, the distance from forming surface 618 of forming tool 602 to charge support 604 is the same as the distance from first end 614 to second end 616. In this illustrative example, first end 620 of forming tool 602 is spaced the same distance from first end 614 of charge support 604 as second end 616 of charge support 604 is from second end 622 of forming tool 602.

[0059] In the second orientation 608, the forming tool 602 forms a variable cross-section into the composite charge on the charge support 604. In the second orientation 608, a forming surface 618 of the forming tool 602 is inclined relative to the charge support 604. Between the first orientation 606 and the second orientation 608, the forming tool 602 moves in a direction 610. The direction 610 is downward toward the charge support 604. When forming the composite charge, the forming tool 602 pivots in a direction 612. By pivoting the forming tool 602 in the direction 612, the second end 622 moves further in the direction 610 than the first end 620. By pivoting the forming tool 602 in the direction 612, the second end 622 moves faster than the first end 620 of the forming tool 602. Pivoting the forming tool 602 during formation of the composite charge reduces wrinkling during formation.

[0060] Attention now turns to FIG. 7, which depicts a schematic front view of a forming tool and charge support prior to punch formation, according to an exemplary embodiment. Forming tool 702 and charge support 706 may be a physical implementation of forming tool 202 and charge support 284 of FIG. 2. Forming tool 702 and charge support 706 may be used to form longitudinal component 301 of FIG. 3. Forming tool 702 may be the same as forming tool 404 of FIGS. 4 and 5. View 700 may be a front view of forming tool 602 and charge support 604 of FIG. 6.

[0061] In view 700, a forming tool 702 is positioned above a composite charge 704 on a charge support 706. In this illustrative example, charge support 706 comprises a first half 708 and a second half 710. In this illustrative example, the gap between first half 708 and second half 710 can vary during the formation of composite charge 704.

[0062] At least one of first half 708 and second half 710 is configured to move away from the other of first half 708 and second half 710 to allow formation of composite charge 704. In this illustrative example, first half 708 is configured to move in direction 716 away from second half 710. In this illustrative example, second half 710 is configured to move in direction 718 away from first half 708.

[0063] Although not depicted in view 700, a movement system is connected to charge support 706 to enable movement of at least one of first half 708 and second half 710. In some illustrative examples, the movement system is configured to enable movement of at least one of first half 708 and second half 710 in multiple axes. By enabling movement in multiple axes, the distance between first half 708 and second half 710 at a first end of charge support 706 can be different from the distance between first half 708 and second half 710 at a second end of charge support 706.

[0064] A plurality of actuators 714 are connected to a back surface 713 of the forming tool 702. The plurality of actuators 714 are aligned longitudinally of the forming tool 702. The plurality of actuators 714 are configured to move the forming surface 712 in a direction 720 toward the composite charge 704. As seen in view 700, the forming surface 712 has a variable cross-section. In view 700, a first end 722 has a narrower cross-section than a second end 724.

[0065] 8A and 8B , a flowchart of a method for punch forming a composite charge is depicted in accordance with an illustrative embodiment. Method 800 may be performed to form a composite part for aircraft 100 of FIG. 1 . Method 800 may be implemented using forming tool 202 of FIG. 2 . Method 800 may be implemented on composite charge 246 of FIG. 2 . Method 800 may generate longitudinal component 300 of FIG. 3 . Method 800 may be implemented using multiple actuators 402 and forming tool 404 of FIGS. 4 and 5 . Method 800 may be implemented using forming tool 602 of FIG. 6 . Method 800 may be implemented on composite charge 704 using forming tool 702 of FIG. 7 .

[0066] Method 800 places a forming tool in contact with the composite charge (operation 802). Method 800 simultaneously activates multiple actuators connected to the forming tool to drive the forming tool toward the composite charge (operation 804). Method 800 then activates the multiple actuators at multiple speeds to generate variable cross-sections in the composite charge (operation 806). Method 800 then simultaneously deactivates the multiple actuators (operation 808). Method 800 then ends.

[0067] In some illustrative examples, placing the forming tool in contact with the composite charge includes placing the forming tool in contact with an entire length of the composite charge (OPERATION 810). In some illustrative examples, placing the forming tool in contact with the composite charge includes placing a center of the forming tool in contact with a center of the composite charge.

[0068] In some illustrative examples, the method 800 applies a clamping force to compress the portion of the composite charge against the forming tool before actuating the plurality of actuators (OPERATION 812). In some illustrative examples, the clamping force clamps a center of the composite charge to a center of the forming tool. In some illustrative examples, the clamping force can be applied by an inflatable bladder.

[0069] In some illustrative examples, method 800 at least partially restrains a portion of the composite charge to maintain tension in the composite charge while actuating the plurality of actuators (OPERATION 814). In some illustrative examples, at least partially restraining a portion of the composite charge includes compressing opposing edges of the composite charge against a forming tool. In some illustrative examples, at least partially restraining a portion of the composite charge includes compressing opposing edges of the composite charge against a charge support below the composite charge. In some illustrative examples, the composite charge is at least partially restrained by a mechanical clamp. In some illustrative examples, the composite charge is at least partially restrained by an inflatable bladder.

[0070] In some illustrative examples, driving the plurality of actuators at the plurality of speeds includes driving actuators at a first end of the forming tool at a different speed than actuators at a second end of the forming tool (OPERATION 816). The end of the forming tool having a wider cross-section is associated with an actuator that operates at a faster speed. In some illustrative examples, the first end of the forming tool has a wider cross-section, and driving the plurality of actuators includes driving the actuators at the first end of the forming tool at a faster speed than the actuators at the second end of the forming tool.

[0071] In some illustrative examples, driving the plurality of actuators at multiple speeds to generate a variable cross-section in the composite charge includes forming the composite charge into a shape having a first height at a first end and a second height at a second end, the second height being different from the first height (OPERATION 818). The actuators that form the greater height in the composite charge will operate at a faster speed than the actuators that form the lesser height in the composite charge. In some illustrative examples, the first height is greater than the second height. In these illustrative examples, the actuators that form the first height at the first end of the composite charge operate at a faster speed than the actuators that form the second height at the second end of the composite charge.

[0072] In some illustrative examples, driving the plurality of actuators at multiple speeds to generate variable cross-sections in the composite charge includes forming the composite charge into a shape having a first width at a first end and a second width at a second end, the second width being different from the first width (Operation 820). In some illustrative examples, actuators that form a larger width in the composite charge will operate at a faster speed than actuators that form a smaller width in the composite charge.

[0073] In some illustrative examples, driving the multiple actuators at multiple speeds to generate variable cross-sections in the composite charge includes rotating a forming tool about an axis of rotation parallel to the width of the composite charge (operation 822). In some illustrative examples, rotating the forming tool includes pivoting the forming tool such that an end of the forming tool having a wider cross-section moves farther than an opposite end of the forming tool having a narrower cross-section. An illustrative example results in some wrinkling reduction by generating a type of twist to the charge through the rotation of the forming tool. The twist is generated by the different speeds of the actuators.

[0074] In some illustrative examples, the plurality of actuators are distributed along a longitudinal axis of the forming tool. In some illustrative examples, driving the plurality of actuators at multiple speeds to generate variable cross-sections in the composite charge includes driving the plurality of actuators at multiple stroke lengths along the longitudinal axis to generate variable cross-sections in the composite charge (OPERATION 824).

[0075] Attention now turns to FIG. 9 , which depicts a flowchart of a method for punch forming a composite charge in accordance with an illustrative embodiment. Method 900 may be used to form a composite part for aircraft 100 in FIG. 1 . Method 900 may be implemented using forming tool 202 in FIG. 2 . Method 900 may be implemented on composite charge 246 in FIG. 2 . Method 900 may generate longitudinal component 300 in FIG. 3 . Method 900 may be implemented using multiple actuators 402 and forming tool 404 in FIGS. 4 and 5 . Method 900 may be implemented using forming tool 602 in FIG. 6 . Method 900 may be implemented on composite charge 704 using forming tool 702 in FIG. 7 .

[0076] The method 900 places a composite charge on a charge support (operation 902). The method 900 drives a forming tool relative to the composite charge toward the charge support using multiple actuators at multiple speeds to generate variable cross-sections in the composite charge (operation 904). The method 900 simultaneously stops the multiple actuators (operation 906). The method 900 then ends.

[0077] In some illustrative examples, the method 900 applies a clamping force to compress the portion of the composite charge against the forming tool prior to actuating the plurality of actuators (operation 908).

[0078] In certain illustrative examples, driving the forming tool toward the charge support relative to the composite charge increases a gap between the first half of the charge support and the second half of the charge support (operation 910).

[0079] In some illustrative examples, driving the multiple actuators at multiple speeds includes driving an actuator at a first end of the forming tool at a different speed than an actuator at a second end of the forming tool (operation 912).

[0080] In some illustrative examples, driving the plurality of actuators at multiple speeds to generate a variable cross-section in the composite charge includes forming the composite charge into a shape having a first height at a first end and a second height at a second end, where the second height is different from the first height (operation 914).

[0081] In some illustrative examples, driving the plurality of actuators at multiple speeds to generate a variable cross-section in the composite charge includes forming the composite charge into a shape having a first width at a first end and a second width at a second end, where the second width is different from the first width (operation 916).

[0082] In some illustrative examples, driving the plurality of actuators at multiple speeds to generate a variable cross-section within the composite charge includes rotating the forming tool about an axis of rotation parallel to the width of the composite charge (operation 918).

[0083] In some illustrative examples, method 900 at least partially restrains a portion of the composite charge to maintain tension in the composite charge while actuating the plurality of actuators (operation 920). In some illustrative examples, at least partially restraining a portion of the composite charge includes compressing opposing edges of the composite charge against a forming tool. In some illustrative examples, at least partially restraining a portion of the composite charge includes compressing opposing edges of the composite charge against a charge support below the composite charge. In some illustrative examples, the composite charge is at least partially restrained by a mechanical clamp. In some illustrative examples, the composite charge is at least partially restrained by an inflatable bladder.

[0084] Attention now turns to FIG. 10 , which depicts a flowchart of a method for punch forming a composite charge in accordance with an illustrative embodiment. Method 1000 may be used to form a composite part for aircraft 100 of FIG. 1 . Method 1000 may be implemented using forming tool 202 of FIG. 2 . Method 1000 may be implemented on composite charge 246 of FIG. 2 . Method 1000 may generate longitudinal component 300 of FIG. 3 . Method 1000 may be implemented using multiple actuators 402 and forming tool 404 of FIGS. 4 and 5 . Method 1000 may be implemented using forming tool 602 of FIG. 6 . Method 1000 may be implemented on composite charge 704 using forming tool 702 of FIG. 7 .

[0085] Method 1000 positions a forming tool in contact with the composite charge (operation 1002). Method 1000 simultaneously activates multiple actuators connected to the forming tool to drive the forming tool toward the composite charge (operation 1004). Method 1000 activates the multiple actuators at multiple stroke lengths to generate variable cross-sections in the composite charge (operation 1006). Method 1000 simultaneously deactivates the multiple actuators (operation 1008). Method 1000 then ends.

[0086] In some illustrative examples, the method 1000 applies a clamping force to compress a portion of the composite charge against the forming tool before actuating the plurality of actuators (OPERATION 1010). In some illustrative examples, the method 1000 at least partially restrains the portion of the composite charge to maintain tension in the composite charge while actuating the plurality of actuators (OPERATION 1012).

[0087] In some illustrative examples, the method 1000 of driving a plurality of actuators at a plurality of stroke lengths includes driving an actuator at a first end of a forming tool at a different stroke length than an actuator at a second end of the forming tool (OPERATION 1014). In some illustrative examples, driving the plurality of actuators at a plurality of stroke lengths to generate a variable cross-section in the composite charge includes forming the composite charge into a shape having a first height at the first end and a second height at the second end, the second height being different from the first height (OPERATION 1016).

[0088] In some illustrative examples, driving the plurality of actuators at multiple stroke lengths to generate a variable cross-section within the composite charge includes rotating the forming tool about an axis of rotation parallel to the width of the composite charge (operation 1018).

[0089] In some illustrative examples, the plurality of actuators are distributed along a longitudinal axis of the forming tool. In some illustrative examples, driving the plurality of actuators at multiple stroke lengths to generate variable cross-sections in the composite charge includes driving the plurality of actuators at multiple speeds along the longitudinal axis to generate variable cross-sections in the composite charge (OPERATION 1020).

[0090] As used herein, the phrase "at least one of," when used in conjunction with a list of items, means that various combinations of one or more of the listed items may be used, and that only one of each item in the list may be required. For example, "at least one of item A, item B, or item C" may include, but is not limited to, item A, item A and item B, or item B. This example may also include item A, item B, and item C, or item B and item C. Of course, any combination of these items is possible. In other examples, "at least one of" may be, for example, but is not limited to, two items A, one item B, and ten items C, four items B, and seven items C, or other suitable combinations. An item may be a specific object, thing, or category. In other words, at least one of means that any combination of items and multiple items may be used from the list, but not all of the items in the list are required.

[0091] As used herein, "a number of," when used in reference to an item, means one or more of the item.

[0092] The flowcharts and block diagrams in the different depicted embodiments depict the architecture, functionality, and operation of some possible implementations of apparatuses and methods in the illustrative embodiments. In this regard, each block in the flowcharts or block diagrams may represent at least one of a module, a segment, a function, or a portion of an operation or step.

[0093] In some alternative implementations of the exemplary embodiments, the function or functions noted in the blocks may occur out of the order noted in the figures. For example, in some cases, two blocks shown in succession may be executed substantially concurrently or may even be executed in the reverse order, depending on the functionality involved. Also, other blocks may be added in addition to the illustrated blocks in a flowchart or block diagram. Some blocks may be optional. For example, operations 810 through 824 may be optional. For example, operations 908 through 920 may be optional. As another example, operations 1010 through 1020 may be optional.

[0094] An exemplary embodiment of the present disclosure will be described with reference to aircraft manufacturing and service method 1100 shown in Figure 11 and aircraft 1200 shown in Figure 12. Attention is initially drawn to Figure 11 , which depicts an illustration of an aircraft manufacturing and service method in block diagram form, in accordance with an exemplary embodiment. During pre-production, aircraft manufacturing and service method 1100 may include specification and design 1102 and material procurement 1104 of aircraft 1200 in Figure 12.

[0095] During production, component and subassembly manufacturing 1106 and systems integration 1108 of the aircraft 1200 occurs. The aircraft 1200 may then go through certification and delivery 1110 to place it in service 1112. While in service 1112 with a customer, the aircraft 1200 is scheduled for routine maintenance and service 1114, which may include modification, reconfiguration, refurbishment, or other maintenance and service.

[0096] Each of the processes of aircraft manufacturing and service method 1100 may be performed or carried out by a system integrator, a third party, and / or an operator. In these examples, the operator may be a customer. For purposes of this description, a system integrator may include, without limitation, any number of aircraft manufacturers and major system subcontractors; a third party may include, without limitation, any number of vendors, subcontractors, and suppliers; an operator may be an airline, a leasing company, the military, a service provider, etc.

[0097] Referring now to Figure 12, an illustration of an aircraft in block diagram form is depicted in which an illustrative embodiment may be implemented. In this example, aircraft 1200 may be produced by aircraft manufacturing and service method 1100 in Figure 11 and may include an airframe 1202 having a number of systems 1204 and an interior 1206. Example systems 1204 include one or more of propulsion system 1208, electrical system 1210, hydraulic system 1212, and environmental system 1214. Any number of other systems may also be included.

[0098] Apparatus and methods embodied herein may be used during at least one of the stages of aircraft manufacturing and service method 1100. One or more illustrative embodiments may be manufactured or used during at least one of component and subassembly manufacturing 1106, system integration 1108, in-service 1112, and maintenance and service 1114 in Figure 11 .

[0099] Illustrative examples provide methods and systems for punch forming longitudinal components having tapered cross sections. Illustrative examples provide methods for punch forming tapered cross section composite stringers. Illustrative examples use variable speed actuators to drive the forming die and simultaneously complete the stroke of each actuator.

[0100] An illustrative example places a composite charge into a punch former. The composite charge can be a net shape or may have a variety of shapes that result in production surplus. An illustrative example uses variable speed forming actuators to depress the forming die so that all portions of the face of the forming die stop at the same time. The actuators start and end at the same time, but cover different distances. An illustrative example results in some wrinkle reduction by creating a kind of twist to the charge. The twist is created by the different speeds of the actuators.

[0101] The illustrative example methods and systems can be used for longitudinal components that have twists, curvatures, or joggles. Determine the position and velocity of each actuator required to complete all actuator strokes simultaneously.

[0102] In some illustrative examples, several release layers are disposed on the charge support. A composite charge is disposed on several release layers. The composite charge is aligned on the charge support to ensure that the composite charge is centered. In some illustrative examples, several release layers are disposed on the composite charge.

[0103] In some illustrative examples, the composite charge can be heated prior to punch forming. The forming die is lowered until the forming surface contacts the composite charge. In some illustrative examples, a series of inflatable bladders are present between the forming tool and the charge support. In some illustrative examples, the inflatable bladders are inflated to apply compression to the composite charge, clamping the composite charge and maintaining tension during forming.

[0104] The composite charge is formed at a variable rate until completion. In some illustrative examples, an inflated bladder within the assembly can relieve pressure buildup during formation. The composite charge is held for a dwell time. After the dwell time, the formed composite charge is removed from the assembly.

[0105] The description of the various exemplary embodiments has been presented for purposes of illustration and description and is not intended to be exhaustive or limited to the embodiments in the form disclosed. Many modifications and variations will be apparent to those skilled in the art. Furthermore, different exemplary embodiments may offer different features as compared to other exemplary embodiments. The selected embodiment or embodiments have been chosen and described in order to best explain the principles and practical applications of the embodiments, and to enable others skilled in the art to understand the disclosure of the various embodiments with various modifications suitable for the particular use contemplated.

[0106] [Additional note 1] A method (800) for punch forming a composite charge (246, 704), comprising: placing (802) a forming tool (202, 404, 602, 702) in contact with the composite charge (246, 704); simultaneously actuating a plurality of actuators (204, 402, 714) connected to the forming tool (202, 404, 602, 702) to drive the forming tool (202, 404, 602, 702) toward the composite charge (246, 704); driving (806) a plurality of said actuators (204, 402, 714) at a plurality of speeds (210) to create a variable cross-section (254) within said composite charge (246, 704); a step (808) of simultaneously stopping the plurality of actuators (204, 402, 714); A method comprising: [Additional note 2] The method described in Appendix 1, wherein the step of driving the plurality of actuators (204, 402, 714) at the plurality of speeds (210) includes a step (816) of driving the actuators (228, 410) at a first end (232, 418) of the forming tool (202, 404, 602, 702) at a speed (230) different from the actuators (212, 412) at a second end (234, 420) of the forming tool (202, 404, 602, 702). [Additional note 3] 2. The method of claim 1, wherein the step of driving a plurality of the actuators (204, 402, 714) at a plurality of the speeds (210) to generate the variable cross-section (254) in the composite charge (246, 704) includes a step (818) of forming the composite charge (246, 704) into a shape having a first height (272, 308) at a first end (268, 304) and a second height (276, 310) at a second end (270, 306), wherein the second height (276, 310) is different from the first height (272, 308). [Additional note 4] 8. The method of claim 1, wherein the step of driving a plurality of the actuators (204, 402, 714) at a plurality of the speeds (210) to generate the variable cross-section (254) in the composite charge (246, 704) includes the step of forming the composite charge (246, 704) into a shape having a first width (274, 309) at a first end (268, 304) and a second width (278) at a second end (270, 306), wherein the second width (278) is different from the first width (274, 309). [Additional note 5] The method of claim 1, wherein the step of placing the forming tool (202, 404, 602, 702) in contact with the composite charge (246, 704) includes (810) placing the forming tool (202, 404, 602, 702) in contact with the entire length (258) of the composite charge (246, 704). [Additional note 6] 2. The method of claim 1, further comprising applying a clamping force (283) to compress a portion (248) of the composite charge (246, 704) against the forming tool (202, 404, 602, 702) before actuating the plurality of actuators (204, 402, 714). [Additional note 7] 2. The method of claim 1, further comprising the step (814) of at least partially restraining a portion of the composite charge (246, 704) and maintaining tension (260) in the composite charge (246, 704) while actuating the plurality of actuators (204, 402, 714). [Additional note 8] The method of claim 1, wherein the step of driving a plurality of the actuators (204, 402, 714) at a plurality of speeds (210) to generate the variable cross-section (254) within the composite charge (246, 704) includes the step (822) of rotating the forming tool (202, 404, 602, 702) about an axis of rotation (240, 504) parallel to the width (256) of the composite charge (246, 704). [Additional note 9] a plurality of said actuators (204, 402, 714) distributed along a longitudinal axis (244) of said forming tool (202, 404, 602, 702); 2. The method of claim 1, wherein the step of driving a plurality of the actuators (204, 402, 714) at a plurality of speeds (210) to generate the variable cross-section (254) in the composite charge (246, 704) includes the step (824) of driving a plurality of the actuators (204, 402, 714) along the longitudinal axis (244) at a plurality of stroke lengths (211) to generate the variable cross-section (254) in the composite charge (246, 704). [Additional Note 10] A punch forming system (201, 282) for a variable cross section (254), comprising: a charge support (284, 604, 706) for supporting the composite charge (246, 704) during formation of the composite charge (246, 704); a forming tool (202, 404, 602, 702) disposed on the charge support (284, 604, 706), the forming tool (202, 404, 602, 702) having a forming surface (208, 408, 618, 712) and a back surface (206, 406, 713); a plurality of actuators (204, 402, 714) connected to the back surface (206, 406, 713) of the forming tool (202, 404, 602, 702) and operable at a plurality of speeds (210) to form the composite charge (246, 704) between the forming surface (208, 408, 618, 712) and the charge support (284, 604, 706); A punch forming system comprising: [Additional Note 11] the charge support (284, 604, 706) comprises a first half (286, 708) and a second half (290, 710); 11. The punch forming system of claim 10, wherein at least one of the first half (286, 708) and the second half (290, 710) is configured to move away from the other of the first half (286, 708) and the second half (290, 710) to enable formation of the composite charge (246, 704). [Additional Note 12] The punch forming system of claim 11 further comprises a movement system (292) connected to the charge support (284, 604, 706) and enabling movement of at least one of the first half (286, 708) and the second half (290, 710) in multiple axes. [Additional Note 13] 11. The punch forming system of claim 10, further comprising a clamping system (201, 282) that compresses the portion (248) of the composite charge (246, 704) against the portion (236, 248) of the forming tool (202, 404, 602, 702) during formation of the composite charge (246, 704). [Additional Note 14] 11. The punch forming system of claim 10, further comprising a composite charge restraint that maintains tension (260) in the composite charge (246, 704) during formation of the composite charge (246, 704) by applying pressure (281) to the composite charge (246, 704) and toward one of the forming tool (202, 404, 602, 702) and the charge support (284, 604, 706). [Additional Note 15] A method (900) for punch forming a composite charge (246, 704), comprising: placing (902) a composite charge (246, 704) on a charge support (284, 604, 706); driving (904) a forming tool (202, 404, 602, 702) against the composite charge (246, 704) toward the charge support (284, 604, 706) using a plurality of actuators (204, 402, 714) at a plurality of speeds (210) to generate a variable cross-section (254) within the composite charge (246, 704); a step (906) of simultaneously stopping the plurality of actuators (204, 402, 714); A method comprising: [Additional Note 16] 16. The method of claim 15, wherein the step of driving the forming tool (202, 404, 602, 702) toward the charge support (284, 604, 706) relative to the composite charge (246, 704) increases (910) a gap (288) between a first half (286, 708) of the charge support (284, 604, 706) and a second half (290, 710) of the charge support (284, 604, 706). [Additional Note 17] 16. The method of claim 15, wherein the step of driving the plurality of actuators (204, 402, 714) at the plurality of speeds (210) includes a step (912) of driving the actuators (228, 410) at a first end (232, 418) of the forming tool (202, 404, 602, 702) at a speed (230) different from the actuators (212, 412) at a second end (234, 420) of the forming tool (202, 404, 602, 702). [Additional Note 18] 16. The method of claim 15, wherein the step of driving a plurality of the actuators (204, 402, 714) at a plurality of the speeds (210) to generate the variable cross-section (254) in the composite charge (246, 704) includes a step (914) of forming the composite charge (246, 704) into a shape having a first height (272, 308) at a first end (268, 304) and a second height (276, 310) at a second end (270, 306), wherein the second height (276, 310) is different from the first height (272, 308). [Additional Note 19] 16. The method of claim 15, wherein the step of driving a plurality of the actuators (204, 402, 714) at a plurality of the speeds (210) to generate the variable cross-section (254) in the composite charge (246, 704) includes a step (916) of forming the composite charge (246, 704) into a shape having a first width (274, 309) at a first end (268, 304) and a second width (278) at a second end (270, 306), wherein the second width (278) is different from the first width (274, 309). [Additional Note 20] 16. The method of claim 15, wherein the step of driving a plurality of the actuators (204, 402, 714) at a plurality of speeds (210) to generate the variable cross-section (254) within the composite charge (246, 704) includes the step (918) of rotating the forming tool (202, 404, 602, 702) about an axis of rotation (240, 504) parallel to a width (256) of the composite charge (246, 704). [Additional Note 21] 16. The method of claim 15, further comprising applying a clamping force (283) to compress a portion (248) of the composite charge (246, 704) against the forming tool (202, 404, 602, 702) before actuating the plurality of actuators (204, 402, 714). [Additional Note 22] 16. The method of claim 15, further comprising at least partially constraining a portion of the composite charge (246, 704) and maintaining tension (260) in the composite charge (246, 704) while actuating the plurality of actuators (204, 402, 714). [Additional note 23] A method (1000) for punch forming a composite charge (246, 704), comprising: placing (1002) a forming tool (202, 404, 602, 702) in contact with the composite charge (246, 704); simultaneously actuating (1004) a plurality of actuators (204, 402, 714) connected to the forming tool (202, 404, 602, 702) to drive the forming tool (202, 404, 602, 702) toward the composite charge (246, 704); driving (1006) a plurality of said actuators (204, 402, 714) at a plurality of stroke lengths (211) to create a variable cross-section (254) within said composite charge (246, 704); a step (1008) of simultaneously stopping the plurality of actuators (204, 402, 714); A method (1000) comprising: [Additional note 24] 24. The method of claim 23, wherein the step of driving the plurality of actuators (204, 402, 714) at the plurality of stroke lengths (211) includes a step (1014) of driving the actuators (228, 410) at a first end (232, 418) of the forming tool (202, 404, 602, 702) at a stroke length (229) that is different from the actuators (212, 412) at a second end (234, 420) of the forming tool (202, 404, 602, 702). [Additional note 25] 24. The method of claim 23, wherein the step of generating the variable cross-section (254) in the composite charge (246, 704) by driving a plurality of the actuators (204, 402, 714) at a plurality of the stroke lengths (211) includes a step (1016) of forming the composite charge (246, 704) into a shape having a first height (272, 308) at a first end (268, 304) and a second height (276, 310) at a second end (270, 306), wherein the second height (276, 310) is different from the first height (272, 308). [Additional note 26] 24. The method of claim 23, further comprising applying a clamping force (283) to compress a portion (248) of the composite charge (246, 704) against the forming tool (202, 404, 602, 702) before actuating the plurality of actuators (204, 402, 714). [Additional note 27] 24. The method of claim 23, further comprising at least partially constraining a portion of the composite charge (246, 704) and maintaining tension (260) in the composite charge (246, 704) while actuating the plurality of actuators (204, 402, 714). [Additional note 28] 24. The method of claim 23, wherein the step of driving a plurality of the actuators (204, 402, 714) at a plurality of the stroke lengths (211) to generate the variable cross-section (254) in the composite charge (246, 704) includes the step (1018) of rotating the forming tool (202, 404, 602, 702) about an axis of rotation (240, 504) parallel to a width (256) of the composite charge (246, 704). [Additional note 29] a plurality of said actuators (204, 402, 714) distributed along a longitudinal axis (244) of said forming tool (202, 404, 602, 702); 24. The method of claim 23, wherein the step of driving a plurality of the actuators (204, 402, 714) at a plurality of the stroke lengths (211) to generate the variable cross-section (254) in the composite charge (246, 704) comprises the step (1020) of driving a plurality of the actuators (204, 402, 714) at a plurality of speeds (210) along the longitudinal axis (244) to generate the variable cross-section (254) in the composite charge (246, 704). [Explanation of symbols]

[0107] 100 aircraft, 102 wing, 104 wing, 106 fuselage, 108 engine, 110 engine, 112 tail, 114 horizontal stabilizer, 116 horizontal stabilizer, 118 vertical stabilizer, 201 punch forming system, 202 forming tool, 204 multiple actuators, 206 back surface, 208 forming surface, 210 multiple speeds, 211 multiple stroke lengths, 212 actuator, 213 stroke length, 214 speed, 216 actuator, 218 speed, 220 actuator, 222 speed, 224 actuator, 226 speed, 228 actuator, 229 stroke length, 230 speed, 232 first end, 234 second end, 236 portion, 238 curvature, 240 axis of rotation, 242 elongated, 243, pivot, 244, longitudinal axis, 245, forming direction, 246, composite charge, 248, portion, 250, longitudinal component, 252, stringer, 254, variable cross section, 256, width, 258, length, 260, tension, 262, rectangular, 264, net shape, 266, trimming, 268, first end, 270, second end, 272, first height, 274, first width, 276, second height, 278, second width, 280, composite charge restraint, 281, pressure, 282, clamping system, 283, clamping force, 284, charge support, 286, first half, 288, gap, 289, void, 290, second half, 292, movement system, 294, first axis, 296, second axis, 301 Longitudinal component, 302, Variable cross section, 304, First end, 306, Second end, 308, First height, 309, First width, 310, Second height, 400, View, 401, First orientation, 402, Multiple actuators, 404, Forming tool, 406, Back surface, 408, Forming surface, 410, Actuator, 412, Actuator, 414, First distance, 416, Second distance, 418, First end, 420, Second end, 422, Direction, 500, View, 501, Second orientation, 502, Direction, 504, Rotation axis, 600, View, 602, Forming tool, 604, Charge support, 606, First orientation, 608, Second orientation, 610, Direction, 612, Direction, 614, First end, 616, Second end, 618, Forming surface, 620, First end, 622 Second end, 700 View, 702forming tool, 704; composite charge, 706; charge support, 708; first half, 710; second half, 712; forming surface, 713; underside, 714; plurality of actuators, 716; direction, 720; direction, 722; first end, 724; second end, 1100; aircraft manufacturing and maintenance methods, 1102; specification and design, 1104; material procurement, 1106; component and subassembly manufacturing, 1108; system integration, 1110; certification and delivery, 1112; in-service, 1114; routine maintenance and service, 1200; aircraft, 1202; airframe, 1204; system, 1206; interior, 1208; propulsion system, 1210; electrical system, 1212; hydraulic system, 1214; environmental system

Claims

1. A method (800) of punch forming a composite charge (246, 704), comprising: placing (802) a forming tool (202, 404, 602, 702) in contact with the composite charge (246, 704); simultaneously actuating a plurality of actuators (204, 402, 714) connected to the forming tool (202, 404, 602, 702) to drive the forming tool (202, 404, 602, 702) toward the composite charge (246, 704); driving (806) a plurality of said actuators (204, 402, 714) at a plurality of speeds (210) to create a variable cross-section (254) within said composite charge (246, 704); a step (808) of simultaneously stopping the plurality of actuators (204, 402, 714); A method comprising:

2. 2. The method of claim 1, wherein the step of driving the plurality of actuators at the plurality of speeds includes the step of driving the actuators at a first end of the forming tool at a different speed than the actuators at a second end of the forming tool.

3. 2. The method of claim 1, wherein driving a plurality of the actuators at a plurality of the speeds to create the variable cross-section in the composite charge includes forming the composite charge into a shape having a first height at a first end and a second height at a second end, the second height being different from the first height.

4. 2. The method of claim 1, wherein driving a plurality of the actuators at a plurality of the speeds to create the variable cross-section in the composite charge includes forming the composite charge into a shape having a first width at a first end and a second width at a second end, the second width being different from the first width.

5. 2. The method of claim 1, wherein placing the forming tool in contact with the composite charge includes placing the forming tool in contact with an entire length of the composite charge.

6. 2. The method of claim 1, further comprising applying a clamping force to compress a portion of the composite charge against the forming tool prior to actuating the plurality of actuators.

7. 10. The method of claim 1, further comprising at least partially restraining a portion of the composite charge to maintain tension in the composite charge while actuating the plurality of actuators.

8. 2. The method of claim 1, wherein driving a plurality of the actuators at a plurality of speeds to create the variable cross-section in the composite charge comprises rotating the forming tool about an axis of rotation that is parallel to a width of the composite charge.

9. a plurality of said actuators (204, 402, 714) distributed along a longitudinal axis (244) of said forming tool (202, 404, 602, 702); 2. The method of claim 1, wherein driving a plurality of the actuators at a plurality of speeds to create the variable cross-section in the composite charge comprises driving a plurality of the actuators along the longitudinal axis at a plurality of stroke lengths to create the variable cross-section in the composite charge.

10. A punch forming system (201, 282) for a variable cross section (254), comprising: a charge support (284, 604, 706) for supporting the composite charge (246, 704) during formation of the composite charge (246, 704); a forming tool (202, 404, 602, 702) disposed on the charge support (284, 604, 706), the forming tool (202, 404, 602, 702) having a forming surface (208, 408, 618, 712) and a back surface (206, 406, 713); a plurality of actuators (204, 402, 714) connected to the back surface (206, 406, 713) of the forming tool (202, 404, 602, 702) and operable at a plurality of speeds (210) to form the composite charge (246, 704) between the forming surface (208, 408, 618, 712) and the charge support (284, 604, 706); A punch forming system comprising:

11. the charge support (284, 604, 706) comprises a first half (286, 708) and a second half (290, 710); 11. The punch forming system of claim 10, wherein at least one of the first half (286, 708) and the second half (290, 710) is configured to move away from the other of the first half (286, 708) and the second half (290, 710) to allow formation of the composite charge (246, 704).

12. 12. The punch forming system of claim 11, further comprising a movement system (292) connected to the charge support (284, 604, 706) and enabling movement of at least one of the first half (286, 708) and the second half (290, 710) in multiple axes.

13. 11. The punch forming system of claim 10, further comprising a clamping system (201, 282) that compresses a portion (248) of the composite charge (246, 704) against a portion (236, 248) of the forming tool (202, 404, 602, 702) during formation of the composite charge (246, 704).

14. 11. The punch forming system of claim 10, further comprising a composite charge restraint that maintains tension (260) in the composite charge (246, 704) during formation of the composite charge (246, 704) by applying pressure (281) to the composite charge (246, 704) and toward one of the forming tool (202, 404, 602, 702) and the charge support (284, 604, 706).

15. A method (900) of punch forming a composite charge (246, 704), comprising: placing (902) a composite charge (246, 704) on a charge support (284, 604, 706); using a plurality of actuators (204, 402, 714) at a plurality of speeds (210) to drive a forming tool (202, 404, 602, 702) against the composite charge (246, 704) toward the charge support (284, 604, 706 to create a variable cross-section (254) within the composite charge (246, 704); a step (906) of simultaneously stopping the plurality of actuators (204, 402, 714); A method comprising:

16. 16. The method of claim 15, wherein driving the forming tool (202, 404, 602, 702) toward the charge support (284, 604, 706) relative to the composite charge (246, 704) increases (910) a gap (288) between a first half (286, 708) of the charge support (284, 604, 706) and a second half (290, 710) of the charge support (284, 604, 706).

17. 16. The method of claim 15, wherein the step of driving the plurality of actuators (204, 402, 714) at the plurality of speeds (210) includes the step (912) of driving the actuators (228, 410) at a first end (232, 418) of the forming tool (202, 404, 602, 702) at a different speed (230) than the actuators (212, 412) at a second end (234, 420) of the forming tool (202, 404, 602, 702).

18. 16. The method of claim 15, wherein driving a plurality of the actuators at a plurality of the speeds to create the variable cross-section in the composite charge includes forming the composite charge into a shape having a first height at a first end and a second height at a second end, the second height being different from the first height.

19. 16. The method of claim 15, wherein driving a plurality of the actuators at a plurality of the speeds to create the variable cross-section in the composite charge includes forming the composite charge into a shape having a first width at a first end and a second width at a second end, the second width being different from the first width.

20. 16. The method of claim 15, wherein driving a plurality of the actuators at a plurality of speeds to create the variable cross-section in the composite charge comprises rotating the forming tool about an axis of rotation that is parallel to a width of the composite charge.

21. 16. The method of claim 15, further comprising applying a clamping force to compress a portion of the composite charge against the forming tool prior to actuating the plurality of actuators.

22. 16. The method of claim 15, further comprising at least partially restraining a portion of the composite charge to maintain tension in the composite charge while actuating the plurality of actuators.

23. A method (1000) of punch forming a composite charge (246, 704), comprising: placing (1002) a forming tool (202, 404, 602, 702) in contact with the composite charge (246, 704); simultaneously actuating a plurality of actuators (204, 402, 714) connected to the forming tool (202, 404, 602, 702) to drive the forming tool (202, 404, 602, 702) toward the composite charge (246, 704); driving (1006) a plurality of said actuators (204, 402, 714) at a plurality of stroke lengths (211) to create a variable cross-section (254) within said composite charge (246, 704); a step (1008) of simultaneously stopping the plurality of actuators (204, 402, 714); A method (1000) comprising:

24. 24. The method of claim 23, wherein the step of driving the plurality of actuators (204, 402, 714) at the plurality of stroke lengths (211) includes the step (1014) of driving the actuators (228, 410) at a first end (232, 418) of the forming tool (202, 404, 602, 702) at a stroke length (229) that is different from the actuators (212, 412) at a second end (234, 420) of the forming tool (202, 404, 602, 702).

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