Needling and welding systems, methods, and devices

Abstract

A method for joining thermoplastic structures is disclosed. The method includes arranging a plurality of thermoplastic structures to form a joint, where the joint has a first side and a second side opposite the first side. The method also includes positioning a charge over a portion of the joint, where the charge comprises a plurality of needles. The method further includes welding the portion of the joint such that the thermoplastic structures are coupled. The welding includes applying a load to at least the first side of the joint or second side of the joint. The welding also includes heating the portion of the joint. The method additionally includes inserting the plurality of needles into the portion of the joint.

Description

Needling and Welding Systems, Methods, and DevicesCROSS REFERENCE TO RELATED APPLICATION

[0001] The present application claims priority to U.S. Provisional Application No. 63 / 525,651, filed on July 7, 2023, the entire contents of which are herein incorporated by reference as if fully set forth in this description.BACKGROUND

[0002] Composite laminate structures, including parts and / or panels, may be used in a variety of industries, such as the aerospace industry, and may be favored for their high strength to weight ratio. It may be desirable to join together one or more composite laminate structures. Currently, adhesives may be used to bond the parts and / or structures together. In addition to adhesives, metal fasteners may be employed to better resist shear and / or peel loading on the joint and to help in transferring loading, and suppressing damage to and / or between the structures. To facilitate installation of the metal fasteners, holes may be drilled into the structures. This may break the fibers of the composite laminate and / or remove material, which may adversely affect the mechanical properties of the structure. Further, load transfer from the fasteners to the structure may create high localized stresses around the fastener holes which may result in various failure modes and / or damage to the composite laminate structure, such as delamination.

[0003] Fastener holes may also allow moisture intrusion into a substructure posing corrosion concerns and / or affecting electronic components housed within the substructure. To mitigate such ingress sealants may be used, adding weight, cost and complexity. Additionally, metal fasteners and composite laminate structures may have differing coefficients of thermal expansion leading to large stresses that must be mitigated. When avehicle structure, such as an aircraft structure, experiences large temperature ranges, differing coefficients of thermal expansion may result in conditions where the metal fastener does not properly fill the fastener hole (e.g., an over-expanded condition or an under-expanded condition). This may ultimately affect how load transfers throughout the structure and may require added structural weight to account for these conditions.

[0004] Accordingly, the present invention seeks to improve structures in a way that effectively transfers loading through the structure.SUMMARY

[0005] Embodiments described herein relate to welding and needling of parts and / or structures, such as fiber reinforced needling with both conductive and non-conductive fibers, as well as unreinforced needles and welding, and, more particularly, to systems, methods, and devices for needling and welding of thermoplastic structures.

[0006] In a first example embodiment, a method for joining thermoplastic structures is provided. The method includes arranging a plurality of thermoplastic structures to form a joint, where the joint has a first side and a second side opposite the first side. The method also includes positioning a charge over a portion of the joint, where the charge includes a plurality of needles. The method further includes welding the portion of the joint such that the thermoplastic structures are coupled. The welding includes applying a load to at least the first side of the joint or second side of the joint. The welding also includes heating the portion of the joint. The method additionally includes inserting the plurality of needles into the portion of the joint.

[0007] In an embodiment, the method further includes cooling the portion of the joint.

[0008] In an embodiment, the method further includes determining a set process time, a set temperature, and a set impact frequency, where the portion of the joint is heated to the set temperature at a rate of heating defined by the set process time and set temperature, and where the plurality of needles are inserted at a rate of insertion defined by the set process time and set impact frequency.

[0009] In such an embodiment, the set process time, the set temperature, and the set impact frequency are based on a material property of at least one thermoplastic structure of the plurality of thermoplastic structures in the joint.

[0010] In such an embodiment, the material property is a glass transition temperature.

[0011] In such an embodiment, the set process time is based on a thickness of the joint and a material property of at least one of the plurality of thermoplastic structures.

[0012] In an embodiment, heating the portion of the joint includes heating the portion of the joint via inductive heating.

[0013] In an embodiment, inserting the plurality of needles into the portion of the joint further includes determining an impact frequency, where an insertion rate for the plurality of needles is based on the impact frequency, and inserting the plurality of needles into the portion of the joint also includes applying, at the determined impact frequency, an ultrasonic impact to the charge.

[0014] In an embodiment, the charge further includes a retaining piece for housing the plurality of needles.

[0015] In such an embodiment, inserting the plurality of needles into the portion of the joint includes applying ultrasonic impact to the charge such that as the charge is compressed the plurality of needles transfer from the retaining piece into the portion of the joint, and where after the plurality of needles are inserted the retaining piece resides on the first surface.

[0016] In an embodiment, a thermoplastic polymer used in each of the plurality of thermoplastic structures in the joint is the same.

[0017] In an embodiment, a thermoplastic polymer of the plurality of needles is the same as a thermoplastic polymer of at least one of the plurality of thermoplastic structures in the joint.

[0018] In an embodiment, subsequent to inserting the plurality of needles into the portion of the joint, the method further includes welding, using inductive heating, the plurality of needles with the portion of the joint, where a thermoplastic polymer in the plurality of needles is melted to fuse with a thermoplastic polymer in the portion of the joint.

[0019] In an embodiment, prior to inserting the plurality of needles into the portion of the joint, the method further includes providing continuous cooling to the plurality of needles such that the plurality of needles is below a predetermined temperature, where the maximum temperature is based on a material property of the plurality of needles.

[0020] In an embodiment, the plurality of needles are inserted into the portion of the joint at a substantially orthogonal angle to the first side.

[0021] In a second example embodiment, a device for joining a thermoplastic structure is provided. The device includes a frame. The device also includes an actuator coupled to the frame and configured to apply a load. The device further includes a heating unit coupled to the frame. The device additionally includes an impact driver coupled at a first end to the frame and at a second end to an impact plate, where the impact plate drivingly engages a charge, where the charge includes a retaining piece and a plurality of needles disposed within the retaining piece. The device also includes a controller coupled to the frame. The controller is configured to weld a portion of the thermoplastic structure. The welding includes applying a load to a side of the portion of the thermoplastic structure. The welding further includes heating the portion of the thermoplastic structure. The controller is further configured to insert, using the impact driver, the charge into the portion of the thermoplastic structure.

[0022] In an embodiment, the device further includes a cooling unit coupled to theframe and configured to provide below ambient temperature air to the charge, such that the plurality of needles are below a maximum temperature in the retaining piece.

[0023] In an embodiment, the controller includes a control panel configured to input a set process time, a set process temperature, and a set impact frequency.

[0024] In such an embodiment, at least one of the set process time, the set temperature, and the set impact frequency is based on a material property of the thermoplastic structure.

[0025] In an embodiment, a material property of the plurality of needles is the same as a material property of the thermoplastic structure.

[0026] In an embodiment, the plurality of needles comprise carbon fiber.

[0027] In a third example embodiment, a robot for joining a thermoplastic structure is provided. The robot includes a base; a robotic arm coupled at a first end to the base, the robotic arm having a joint and movable in six degrees of freedom; and a tool coupled to a second end of the robotic arm. The tool includes a frame having a first arm a second arm, the first arm disposed at a distance from the second arm and configured to allow a portion of the thermoplastic structure to be disposed between the first and second arms. The tool also includes an inductive heating unit coupled to the frame, where a first portion of the inductive heating unit is coupled to the first arm and a second portion of the inductive heating unit is coupled to the second arm. The tool further includes an impact driver coupled to the first arm of the frame, where the impact driver is drivingly engaged with a charge, where the charge comprises a plurality of needles. The tool additionally includes an actuator coupled to the second arm of the frame and configured to apply a load to the portion of the thermoplastic structure disposed between the first and second arms. The robot also includes a controlleroperably connected to the robot. The controller is configured to cause the robot to perform the operation of welding the portion of the thermoplastic structure. The welding includes applying, using the actuator, the load to a side of the portion of the thermoplastic structure. The welding also includes heating, using the inductive heating unit, the portion of the thermoplastic structure to a set temperature. The controller is also configured to cause the robot to perform the operation of inserting, using the impact driver, the plurality of needles into the portion of the thermoplastic structure.

[0028] In a fourth example embodiment, a charge is provided. The charge includes a plurality of needles. The charge also includes a retaining piece, compressible between an uncompressed position and a compressed position, where the plurality of needles are disposed substantially within the retaining piece at an angle in the uncompressed position, and where the plurality of needles are disposed substantially outside of the retaining piece in the compressed position.

[0029] In an embodiment, the plurality of needles comprise carbon fiber.

[0030] These as well as other aspects, advantages, and alternatives will become apparent to those of ordinary skill in the art by reading the following detailed description, with reference, where appropriate, to the accompanying drawings.BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure l is a welding and needling device, according to exemplary embodiments of the present invention.

[0032] Figure 2 is a perspective view of a charge, according to exemplary embodiments of the present invention.

[0033] Figure 3 is a perspective view of a robot for welding and needling a work piece, according to exemplary embodiments of the present invention.

[0034] Figure 4 is a cutaway view of inductively welding thermoplastic laminates, according to exemplary embodiments of the present invention

[0035] Figures 5A-5C are perspective views of a welding and needling process, according to exemplary embodiments of the present invention.

[0036] Figure 6 is a flow chart of an example method for joining thermoplastic structures, according to an exemplary embodiment of the present disclosure.

[0037] Figure 7 is a simplified block diagram showing some of the components of an example computing device, according to an exemplary embodiment of the present disclosure.DETAILED DESCRIPTION

[0038] Thermoplastics may be used in a variety of applications, such as in thermoplastic composites. At certain temperatures, thermoplastics may change from a solid state to a plastic or liquid state, allowing for increased workability. In thermoplastic composites, the thermoplastic may be a matrix. Thermoplastic composites may be heated to soften the matrix, allowing them to be shaped or joined with another thermoplastic structure. For example, multiple thermoplastic composites may be heated to a specific temperature, such as a glass transition temperature, and a load may be applied to the composites to weld them together. During the welding process, the thermoplastic matrices in a first and a second composite structure undergo a phase change to either a plastic or liquid state. In the plastic or liquid phase, and in some instances under the applied load, fusing of the thermoplastic matrices occurs between a portion of each thermoplastic composite. Further, softening of thermoplastic matrix may facilitate the installation of additional material. For example, a thermoplastic composite laminate may be heated to soften the thermoplastic matrix and a fastening device, such as a carbon needle, may be inserted into the softened laminate. One example of this process is three-dimensional (3D) carbon needling. Such a process may allow for fastening devices to be installed without generating fastener holes in the composite laminate, which may cause damage to the structure and weaken the mechanical properties.

[0039] Disclosed herein are example systems, methods, and devices for accomplishing 3D needling and welding of thermoplastic structures. The disclosed systems, methods, and devices may be utilized in any device or application where joining of structures by inductive welding and / or needling may occur. For example, the inductive welding and / or needling may be used to join structures of a vehicle, including but not limited to a ground vehicle (e.g., an automobile), a sea vehicle (such as a boat), or a flying craft (such as anaerial, floating, soaring, hovering, airborne, aeronautical aircraft, airplane, plane, spacecraft, a helicopter, an airship, or an unmanned aerial vehicle, a vertical take-off and landing (VTOL) craft, or a drone). The disclosed embodiments of the present invention may be used in any of these applications in order to obtain advantages such as localized welding and needling of specific portions of structures, providing shear flow between structures without the need to drill and install traditional fasteners (e.g., nuts and bolts), and reducing the weight of the structure by minimizing the use of traditional fasteners.

[0040] Figure 1 is a welding and needling device 100, according to exemplary embodiments of the present invention. In some embodiments, the device 100 may include a frame 104, a heating unit 110, a driver assembly 120, and an actuator assembly 130. In some embodiments, the frame 104 may include a control panel 106, a controller 108, and a housing 102.

[0041] In some embodiments, the frame 104 may define a C-Shape having a first member 104 A and a second member 104B facing one another and connected by a vertical member. In some embodiments, the heating unit 110 and the driver assembly 120 may be coupled to the first member 104 A, and the heating unit 110 and actuator assembly 130 may be coupled to the second member 104B. Thus, in some embodiments, the heating unit 110 may include one or more heating coils disposed opposite one another on both the first member 104 A and the second member 104B. The first and second members, 104 A and 104B respectively, may be separated by a distance to allow components and / or work pieces, such as thermoplastic laminates, to be disposed within the gap. In some embodiments, the thermoplastic laminates may take the form of a first thermoplastic laminate 202 and a second thermoplastic laminate 204. The first thermoplastic laminate 202 and a second thermoplasticlaminate 204 may each respectively include a portion disposed within the gap between the first member 104A and the second member 104B of the frame 104.

[0042] In some embodiments, the housing 102 may be configured to house components of the device 100. For example, various components of the heating unit 110, the driver assembly 120, and / or the actuator assembly 130 may be disposed within the housing 102. The various components disposed within the housing 102 may include hardware and / or software utilized by the heating unit 110, the driver assembly 120, and / or the actuator assembly 130. In some embodiments, the control panel 106 and the controller 108 of the device 100 may be disposed both inside of the housing 102 and on an external surface of the housing 102. For example, the control panel 106 may have settings disposed on the external surface of the housing 102 that are configured to input a set process time, a set temperature, and / or a set impact parameter, such as an impact frequency. The set process time may specify the cycle time that the device 100 operates the heating unit 110 and / or the driver assembly 120. The set temperature on the control panel 106 may control a maximum temperature that the heating unit 110 heats the work piece to, such as the thermoplastic laminates. The set impact frequency on the control panel 106 may control the maximum impact frequency that the driver assembly 120 operates during the process. In some embodiments, the set process time, the set temperature, and / or the set impact frequency may be based on a material property and / or a mechanical property of the thermoplastic laminates. In some embodiments, the set process time, the set temperature, and / or the set impact frequency may be based on a material property and / or a mechanical property of the carbon needles.

[0043] In some embodiments, the control panel 106 may include a knob, a dial, abutton, or any other adjustable input. In some embodiments the control panel 106 may be a digital display, while in other embodiments the control panel 106 may be analog. The control panel 106 may allow a user to set a specific process parameter for operation of the device 100. Various components of the control panel 106, such as circuitry and / or electronics, may be disposed inside of the housing 102. In some embodiments, the controller 108 may be configured to operate the device 100 at the parameters set on the control panel 106. In some embodiments, the controller 108 may be a trigger, while in other embodiments the controller 108 may be a button or a switch.

[0044] While Figure 1 illustrates the controller 108 and the control panel 106 disposed on the housing 102, in some embodiments, the controller 108 and / or the control panel 106 may be located elsewhere. For example, the controller 108 may be actuated by a foot pedal, while the control panel 106 may be located on a computing device in communication with the device 100.

[0045] In some embodiments, the device 100 may be configured to couple with one or more external power sources to operate the various components. For example, the frame 104 may include a fitting to couple with an air supply and / or an electricity supply. In some embodiments, the air supply may be used to power the driver assembly 120, while the electricity supply may power the actuator assembly 130, the heating unit 110, the controller 108, and / or the control panel 106. In other embodiments, the device 100 may be configured to operate electrically without using the air supply, such that the driver assembly 120 is powered by the electrical supply.

[0046] In some embodiments, the actuator assembly 130 may include an actuator 132, a load cell 134, and an impact backer plate 136. In some embodiments, the actuator 132 maybe coupled by the controller 108 and operable to apply an adjustable load to at least one side of the thermoplastic laminates. For example, the actuator 132 may apply an adjustable load to a surface of the thermoplastic laminates, such as a surface of the second thermoplastic laminate 204. In some embodiments, the actuator 132 may be in communication with the control panel 106, which may set the adjustable load applied by the actuator 132. In some embodiments, the load applied by the actuator 132 may be determined based on characteristics of the thermoplastic laminates being joined, while in other embodiments the load may be based on other factors. The load applied by the actuator 132 may serve to secure the thermoplastic laminates during processing.

[0047] In some embodiments, the applied load from the actuator assembly 130 may assist in welding the thermoplastic laminates together. For example, the load applied by the actuator assembly 130 may force a surface of the first thermoplastic laminate 202 to be in contact with a surface of the second thermoplastic laminate 204. As heat is applied from the heating unit 110, the matrices in the first and second thermoplastic laminates 202 and 204 may soften. The applied load from the actuator assembly 130 may force the softened surfaces of the first and second thermoplastic laminates 202 and 204 together. This may assist in interaction between the matrices of the respective thermoplastic laminates, welding the surface of the first thermoplastic laminate 202 with the surface of the second thermoplastic laminate 204. In some embodiments, the actuator assembly 130 may continue to apply the load (e.g., at a constant force) until the welded thermoplastic laminates have cooled, for example to ambient room temperature. Applying the load until the thermoplastic laminates have cooled may allow the softened surfaces to remain in contact until the surfaces have hardened together, thus providing for a stronger weld bond.

[0048] The actuator 132 may be communicatively coupled to the load cell 134. In some embodiments, the load cell 134 may provide feedback to the actuator 132 and / or the control panel 106 regarding the applied load. For example, when the set load has been reached, the load cell 134 may communicate to hardware and / or software controlling the actuator 132, such as the control panel 106, to cease increasing the applied load and hold the load at a constant force. The load cell 134 may provide real-time feedback to the actuator 132 regarding the applied load. In some embodiments, the impact backer plate 136 may be coupled to the load cell 134 and disposed between the thermoplastic laminates and the load cell 134. The impact backer plate 136 may be in contact with the thermoplastic laminates and apply the load from the actuator 132. The impact backer plate 136 may be configured to distribute the load from the actuator 132 across a portion of the thermoplastic laminates. In some embodiments, evenly distributing the loading over the portion of the thermoplastic laminates may reduce the occurrence of warping during processing due to uneven forces. Thus, even distribution of loading may produce more consistent joining of the portion of thermoplastic laminates.

[0049] As shown in the embodiment illustrated in Figure 1, the actuator assembly 130 may be coupled to the second member 104A of the frame 104. However, the actuator assembly 130 may be coupled elsewhere on the device 100. In some embodiments, the actuator assembly 130 may be remote from the device 100, and communicatively coupled to the device 100 such that it may be controlled by the controller 108. While one actuator assembly 130 is illustrated in Figure 1, in some embodiments, the device 100 may include more than one actuator assembly 130.

[0050] In some embodiments, the heating unit 110 may be disposed on the first and / orsecond members 104 A and 104B of the frame 104 having a space where the work pieces desired for processing may be placed. The heating unit 110 may be coupled to the control panel 106 such that the temperature setting on the control panel 106 controls a temperature that the heating unit 110 heats the work pieces to.

[0051] Operation of the heating unit 110 may be accomplished through actuation of the controller 108. In some embodiments, the heating unit 110 may be an induction heating unit, although other heating methods of heating are possible. With induction heating, the heating unit 110 may include one or more induction heating coils. For example, the heating unit 110 may have one or more induction heating coils on the first member 104A and the second member 104B to facilitate heating of the thermoplastic laminates. Heating multiple sides of the thermoplastic laminates may allow for faster process times and / or more even heating throughout the thermoplastic laminates. Even heating throughout the thermoplastic laminates may provide better process control. For example, the occurrence of warping during processing that arises from unequal thermal expansion between the thermoplastic laminates due to significant temperature differences may be reduced.

[0052] The portion of the thermoplastic laminates disposed within the heating unit 110 may be heated via the induction coils to the set process temperature on the control panel 106. The heating rate at which the heating unit 110 heats the thermoplastic laminates, via the induction coils, may be determined by the set process time on the control panel 106. In some embodiments, including the first and second thermoplastic laminates 202 and 204, the set process temperature and / or the set process time may be based on a material property of either the first and / or the second thermoplastic laminate 202 and 204. In one example, the set process temperature that the heating unit 110 operates may be a glass transition temperatureof the first thermoplastic laminate 202 and / or a glass transition temperature of the second thermoplastic laminate 204, while in another example the set process temperature may be higher than or lower than the glass transition temperature of the first thermoplastic laminate 202 or the second thermoplastic laminate 204.

[0053] In some embodiments, the heating unit 110 may facilitate welding between the first and second thermoplastic laminates 202 and 204. For example, the heating unit 110 may heat the portion of the first and second thermoplastic laminates 202 and 204 to the set process temperature, such as the glass transition temperature. This may cause a matrix in the first and second thermoplastic laminates 202 and 204 to soften, allowing the matrix in the first thermoplastic laminate 202 to interact with the matrix in the second thermoplastic laminate 204. For example, when the set temperature is reached, welding between a surface of the first thermoplastic laminate 202 in contact with a surface of the second thermoplastic laminate 204 may occur. Welding may provide fixed coupling between the thermoplastic laminates. The load applied by the actuator assembly 130 may assist in welding the first and second thermoplastic laminates 202 and 204 by urging interaction between the softened matrices. However, in other embodiments, welding may be performed using the heating unit 110 without the aid of the actuator assembly 130.

[0054] In some embodiments, a material property of the first thermoplastic laminate 202 is the same as and / or similar to a material property of the second thermoplastic laminate 204. For example, the matrix of the first thermoplastic laminate 202 may be the same as and / or similar to the matrix of the second thermoplastic laminate 204. Same and / or similar matrices between the first and second thermoplastic laminates 202 and 204 may allow for improved welding between the respective parts, as the matrices may have same and / or similartemperature ranges in which welding may be accomplished, such as the same glass transition temperature. This may allow for improved interaction between the respective thermoplastic matrices, which may produce a stronger bond between the first and second thermoplastic laminates 202 and 204.

[0055] However, in other embodiments it may be desirable to join two or more parts having differing material properties. For example, a first part may be a thermoplastic or thermoplastic composite and a second part may be a thermoset composite. In another example, the first part may be a thermoplastic based part and the second part may be another thermoplastic based part having a material property different than the first part. Other examples are also possible. Thus, in some embodiments two or more dissimilar parts may be joined through needling.

[0056] In some embodiments, the heating unit 110 may facilitate welding between carbon needles and the first and second thermoplastic laminates 202 and 204. After the carbon needles are driven into the first and second thermoplastic laminates 202 and 204, it may be desirable to couple the carbon needles to the structure to prevent migration of the carbon needles and / or allow for more effective load transfer between the respective parts, for example. While the carbon needles are disposed within the first and second thermoplastic laminates 202 and 204, the heating unit 110 may continue to provide heating such that a matrix of the carbon needles softens and interacts with the matrices of the first and second thermoplastic laminates 202 and 204. Interaction between the matrices may fixedly weld the carbon needles in the desired position.

[0057] In some embodiments, a material property of the carbon needles is the same as and / or similar to a material property of either the first thermoplastic laminate 202 and / orthe second thermoplastic laminate 204. For example, the matrix of the carbon needles may be the same as and / or similar to the matrix of either the first thermoplastic laminate 202 and / or the second thermoplastic laminate 204. Same and / or similar matrices between the carbon needles and either the first and / or second thermoplastic laminates 202 and 204 may allow for improved welding between the respective parts, as the matrices may have same and / or similar temperature ranges in which welding may be accomplished, such as a same glass transition temperature.

[0058] In some embodiments, the driver assembly 120 may include an impact driver 122 and an impact plate 124 coupled to an end of the impact driver 122. The impact driver 122 may be coupled to the first member 104A, having a portion of the impact driver 122 disposed within the housing 102. The driver assembly 120 may be coupled to the control panel 106 and controlled by the controller 108. The set impact parameter (e.g., the set impact frequency) on the control panel 106 may control the impact pressure or force of any frequency and / or spectrum of the impact driver 122 during operation. In some embodiments, the impact driver 122 may be pneumatically powered, while in other embodiments the impact driver 122 may be electrically powered. In some embodiments, the impact driver 122 may be an ultrasonic impact driver.

[0059] In some embodiments, the impact plate 124 may be configured to contact and / or engage a charge 150 disposed between the impact plate 124 and the thermoplastic laminates. During operation, the actuation of the controller 108 may begin operation of the impact driver 124 at the set impact frequency. The impact driver 124 may force the charge 150, by way of the impact plate 122, toward the thermoplastic laminates that are heated by the heating unit 110. As the impact driver 124 presses against the charge 150 the carbonneedles disposed within the charge 150 may be driven into the heated thermoplastic laminates.

[0060] In some embodiments, it may be desirable to cool the carbon needles disposed within the charge 150 prior to being driven into the thermoplastic laminates. For example, as the thermoplastic laminates are inductively heated by the heating unit 110, the heating unit 110 may similarly produce heating of the carbon needles due to the proximity of the charge 150 to the heating unit 110. In some embodiments, such heating of the carbon needles prior to insertion may be undesirable. For example, such heating may soften the carbon needles making it more difficult to effectively drive the carbon needles into the thermoplastic laminates. Softened carbon needles may also bend, buckle, and / or warp during insertion which may cause the carbon needles to be driven into the thermoplastic laminates at an unintended angle.

[0061] In some embodiments, the carbon needles within the charge 150 are cooled prior to insertion into the thermoplastic laminates. The device 100 may include a cooling unit 140 configured to supply cooling to the carbon needles. For example, the cooling unit 140 may include a gas supply nozzle that circulates the gas at a specified temperature to maintain the temperature of the carbon needles below a threshold temperature. The threshold temperature may be a temperature based on a material property of the carbon needles (e.g., a temperature at which the material property increases or decreases). In some embodiments, the cooling unit 140 may supply ambient temperature gas to the charge 150, while in other embodiments, the gas may be below ambient temperature. Any suitable gas may be used. For example, the cooling unit 140 may be coupled to a compressed air supply or a nitrogen supply. In some embodiments, the cooling unit 140 may regulate the temperature of thecarbon needles without using gas. In some embodiments, the cooling unit 140 may be communicatively coupled to the control panel 106. The control panel 106 may include a cooling setting for inputting a set cooling temperature that the cooling unit 140 is to operate.

[0062] Cooling the carbon needles may be accomplished in a variety of ways. For example, the device 100 may include internal cooling channels that provide the cooling to the carbon needles, such as by circulating a cooling gas or liquid. While in other examples, an external cooling device may be coupled to the device 100 and provide cooling to the carbon needles. Thus, cooling may be performed using an internal and / or external cooling device. In some embodiments, the thermoplastic laminates may be cooled. For example, it may be desirable to cool the thermoplastic laminates while heating the needles (e.g., carbon needles). In some embodiments, it may be desirable to insert a metal needle into the thermoplastic laminates. In such examples, the thermoplastic laminates may be joined (e.g., welded) then cooled prior to insertion of the needles (e.g., metal needles). The metal needles may be heated to facilitate insertion into the thermoplastic laminates. Thus, in some embodiments the carbon needles may be cooled, the thermoplastic laminates may be cooled, and / or both the carbon needles and the thermoplastic laminates may be cooled at different stages of the needling and welding process.

[0063] Figure 2 is perspective view of the charge 150, according to exemplary embodiments of the present invention. In some embodiments, the charge 150 may include a plurality of carbon needles 152 disposed within a retaining piece 154. In some embodiments, the charge 150 may take the form of a cartridge having the carbon needles 152 preloaded so as to be disposed within the retaining piece 154. The charge 150 may be loaded into a device, such as the device 100 of Figure 1, and positioned over the thermoplasticlaminates. During operation, the charge 150 may be engaged by the impact driver 122 by way of the impact plate 124. The impact driver 122 may drive the charge 150 onto the thermoplastic laminates. As the charge 150 is compressed, the carbon needles 152 may transfer from the retaining piece 154 and into the thermoplastic laminates. After the carbon needles 152 have been driven into the thermoplastic laminates, the retaining piece 154 may remain on a surface of the thermoplastic laminates in a compressed state.

[0064] In some embodiments, the carbon needles 152 may comprise a matrix and a carbon fiber. In some embodiments, the matrix may be a thermoplastic, while in other embodiments, the matrix may be a thermoset. The thermoplastic matrix of the carbon needles 152 may be the same as or similar to the matrix used in the thermoplastic laminates. Using the same or similar thermoplastic matrix for the carbon needles 152 may allow for welding to occur between the carbon needles 152 and the thermoplastic laminates. The carbon fiber of the carbon needles 152 may be any suitable orientation and / or pattern. In one embodiment, the carbon needles 152 may include a unidirectional carbon fiber and a thermoset matrix. The unidirectional carbon fiber may be oriented along the length of the carbon needles 152 such that the unidirectional fibers run from a first end to a second end of the carbon needles 152. A dimension of the carbon needles 152 may vary based on the desired application. For example, a thickness and / or a length may be chosen based on a dimension of the thermoplastic laminates that the carbon needles 152 are to be inserted into.

[0065] In some embodiments, at least one end of the carbon needles 152 may comprise a point. The pointed end of the carbon needles 152 may be oriented substantially toward the thermoplastic laminates. During insertion of the carbon needles 152 into the thermoplastic laminates, the pointed end may facilitate easier insertion. The pointed end mayalso allow the carbon needles 152 to bypass the fibers of the thermoplastic laminates, allowing for insertion while mitigating breaking of the fiber. Breaking of the fibers of the thermoplastic laminates may adversely impact the mechanical properties of the thermoplastic laminates. Thus, mitigation of fiber breaking during insertion of the carbon needles 152 by utilizing a pointed end may advantageously produce better mechanical properties in the thermoplastic laminates than using a non-pointed end.

[0066] While carbon needles are described above, in some embodiments it may be desirable for another needle material to be used. For example, the needles may be made from the thermoset or thermoplastic matrix using another fiber, such as glass or aramid. The orientation of the fiber and / or the ratio of fiber to matrix may vary based on the desired application. Thus, in embodiments the needles may include a thermoplastic material, a thermoset material, and / or a reinforcement material (e.g., metallic, ceramic, inorganic, or carbon based material). However, in other examples the needles may be made from a metal including metal alloys. In some embodiments, the metal needles may retain material properties at elevated temperatures compared to the material to be joined (e.g., the composite laminates), which may mitigate undesirable deformation of the needles during insertion into the material. Thus, in some embodiments a material property of the needles may be the same as a material property of the joint that the needles are inserted into, while in other embodiments a material property of the needles may be different than a material property of the joint.

[0067] The retaining piece 154 may be made from any suitable material. For example, the retaining pieces 154 may include an open cell foam. In some embodiments, a dimension of the retaining piece 154, such as a length and / or width, may be based on adimension of the thermoplastic laminates, while in other embodiments, a dimension of the retaining piece 154 may be based on a dimension of a component of the device 100, such as the impact plate 124. A thickness of the retaining piece 154 may be less than, equal to, or greater than a length of the carbon needles 152. In some embodiments, the retaining piece 154 may be substantially flat on a side, having a thickness on a first end equal to a thickness on a second end. The term “substantially flat,” as used herein, may account for thickness variations of the retaining piece 154 between 0 degrees and 5 degrees, between 5 degrees and 10 degrees, between 10 degrees and 15 degrees, and / or between 15 degrees and 20 degrees. In some embodiments, substantially flat may be based on a manufacturing tolerance in producing the retaining piece 154. However, in other embodiments, the retaining piece 154 may be tapered to have the thickness on the first end different from the thickness on the second end. For example, a thermoplastic laminate (e.g., first thermoplastic laminate 202) may be tapered on a first surface such that a given cross-section may vary in thickness. In such an example, the retaining piece 154 may match the slope of the first surface to allow the carbon needles 152 to be inserted at the desired angle (e.g., orthogonal).

[0068] The carbon needles 152 may be disposed within the retaining piece 154 in any suitable arrangement based on the needs of the application. For example, the arrangement of the carbon needles 152 within the retaining piece 154 may depend on a type of stress the thermoplastic laminates may experience. In some embodiments, the carbon needles 152 may be arranged in-line with one another, while in other embodiments the carbon needles 152 may be in an offset arrangement. Similarly, the density of carbon needles 152 within the retaining piece 154 (e.g., carbon needles per square inch) may vary based on the desired application. The carbon needles 152 may be disposed at any suitable angle within the retaining piece 154. The angle of the carbon needles 152 may be based on a desired insertionangle into the thermoplastic laminates. In some embodiments, the desired insertion angle of the carbon needles 152 may depend on a type of stress the thermoplastic laminates may experience, such as shear stress. In some embodiments, the carbon needles 152 are disposed within the retaining piece 154 so as to form an orthogonal angle (e.g., 90 degrees) with the thermoplastic laminates. However, other angles may also be used.

[0069] Thus, the charge 150 may be customizable based on the needs of application. Customizability of the charge 150 may allow for better joining of thermoplastic laminates. On vehicles, such as an aircraft, stresses often vary based on where a part may be located. With parts comprising thermoplastic laminates, the types of stresses experienced may determine the density, angle, dimensions, and / or arrangement pattern of the carbon needles 152 used to join the thermoplastic structures. Thus, a customizable charge may provide increased variability in application to the types of thermoplastic laminates being joined. Because the charge 150 may be standardized in some applications and manufactured prior to use in the device 100, utilizing the charge 150 may allow for consistent and efficient joining of thermoplastic laminates. Thus, the charge 150 may reduce costs associated with processing time and / or reduce human error that may otherwise result from incorrect needle alignment within the thermoplastic structures.

[0070] Figure 3 is a perspective view of a robot 300 for welding and needling a work piece, according to exemplary embodiments of the present invention. In some embodiments, the robot 300 may include a base 302, an arm 306 having joints 304 movable in six degrees of freedom, and an attachment head 308. The arm 306, together with the joint 304, may allow the robot 300 to position the attachment head 308 over a work area. The attachment head 308 may be configured to couple to a tool. In some embodiments, the attachment head308 may couple to the device 100. The device 100 coupled to the attachment head 308 may have all functionality described with respect to Figure 1. Thus, the robot 300 may facilitate joining of work pieces, such as thermoplastic laminates, through welding and / or carbon needling.

[0071] While the embodiment illustrated in Figure 3 has a single arm 306, the robot 300 may have more than one arm. For example, the robot 300 may have two arms, with each arm having joints and / or the attachment head 308. In one embodiment where the robot 300 includes two arms, the device 100 may be divided into two sections. For example, a first attachment head on a first arm of the robot 300 may couple to the first member 104 A of device 100, and a second attachment head on a second arm of the robot 300 may couple to the second member 104B of device 100. This may allow the robot 300 to join portions of the thermoplastic laminates having a dimension outside of a tolerance for the device 100, such as joining thermoplastic laminates that may be unreachable by the device 100.

[0072] In some embodiments, the robot 300 may be coupled to a magazine containing the charge 150. The magazine may supply the charge 150 to the device 100 attached to attachment head 308 as the robot 300 performs operations. In some embodiments, the magazine may hold more than one charge which may be fed as needed to the device 100 for reloading between needling operations. The magazine may thus allow for quick and efficient reloading of charges into the device 100 without requiring the aid of a user. This may decrease operational costs and / or may increase safety of operation by not requiring the user to interact with moving components of the robot 300.

[0073] In some embodiments, the robot 300 may be coupled to a controller 310 configured to control operations of the robot 300. For example, the controller 310 may causethe tool, such as the device 100, coupled to the attachment head 308 to weld a portion of the thermoplastic laminates. In welding the portion of the thermoplastic laminates, the controller 310 may cause the robot 300 to apply a load (e.g., using an actuator) to a side of the portion of thermoplastic laminates and / or heat the portion of the thermoplastic laminates to a set temperature. The heating may be performed using an induction heating unit. The controller 310, may cause the robot 300 to insert the carbon needles into the portion of the thermoplastic laminates. Inserting the carbon needles may be performed using an impact driver, for example. In some embodiments, the controller 310 may cause the robot 300 to weld the inserted carbon needles with the portion of the thermoplastic laminates.

[0074] Figure 4 is a cutaway view of inductively welded thermoplastic laminates 400, according to exemplary embodiments of the present invention. In some embodiments, a portion of a first thermoplastic laminate 502 and a portion of a second thermoplastic laminate 504 bay be overlapped to form a joint. An inductive heating unit 410 may be disposed on either side of the joint. The inductive heating unit 410 may include an induction coil. A load 430 may be applied to at least one side of the joint to encourage contact between the first and second thermoplastic laminates 502 and 504. In the embodiment illustrated in Figure 4, two heating units 410 are shown, a first heating unit is disposed on a first side of the joint, and a second heating unit is disposed on a second side of the joint.

[0075] The inductive coils of the inductive heating unit 410 may induce eddy currents 412 in the first and second thermoplastic laminates 502 and 504. This may heat the first and second thermoplastic laminates 502 and 504 to a set temperature which may cause the portions of the respective thermoplastic laminates in the joint to soften. At the set temperature, contacting surfaces of the first and second thermoplastic laminates 502 and 504may weld together, forming a welded surface 406. The load 430 may enhance the formation of the welded surface 406 by encouraging contact between the first and second thermoplastic laminates 502 and 504 in the softened state.

[0076] Figures 5A-5C are perspective views of a welding and needling process 500, according to exemplary embodiments of the present invention. As shown in Figure 5A, the example welding and needling process may include the first thermoplastic laminate 502, the second thermoplastic laminate 504, and a charge 550 including carbon needles 552 disposed within a retaining piece 554. A portion of the first thermoplastic laminate 502 may be positioned over a portion of the second thermoplastic laminate 504 such that surfaces of the respective thermoplastic laminates are overlapped and / or in contact. In some embodiments, such overlap and / or contact may be referred to as a joint. In some embodiments, the portions of overlapping and / or contacting surfaces of the first and second thermoplastic laminates 502 and 504 may be the portions of the first and second thermoplastic laminates 502 and 504 that are desired to be joined by welding and / or needling. The charge 550 may be positioned over the portion of the first and second thermoplastic laminates 502 and 504. The charge 550 may be positioned according to a desired angle alignment of the carbon needles 552 with respect to the first and second thermoplastic laminates 502 and 504. For example, the charge 550 may be positioned so that the carbon needles 552 form an orthogonal angle with the portion of the first and second thermoplastic laminates 502 and 504. In some examples, the carbon needles 552 may be substantially orthogonal, such as exactly orthogonal or a deviation from orthogonal (e.g., + / - 1 to 2 degrees from orthogonal). However, other angles may also be used. While Figure 5A illustrates the first and second thermoplastic laminates 502 and 504 forming a single lap joint, in other embodiments welding and / or needling may involve other types of joints. For instance, the first and second thermoplastic laminates 502 and 504 mayform a single lap joint, a double lap joint, a scarf joint, a double scarf joint, a stepped joint, and a double stepped joint.

[0077] In some embodiments, the first and second thermoplastic laminates 502 and 504 may be heated to a set temperature. The set temperature may be determined based on a material property of either the first and / or second thermoplastic laminates 502 and 504. For example, the set temperature may be the glass transition temperature. In some embodiments, heating the first and second thermoplastic laminates 502 and 504 to the set temperature may allow for welding to occur between contacting surfaces of respective laminates. Heating may also allow for easier insertion of the carbon needles 552 and / or may mitigate damage to the thermoplastic laminates and / or the carbon needles 552 during insertion. In some embodiments, the heating is performed using inductive heating, however other heating methods may be used.

[0078] In the embodiment illustrated in Figure 5B, after the first and second thermoplastic laminates 502 and 504 have been heated to the set temperature, the carbon needles 552 may be inserted into the respective thermoplastic laminates. In some embodiments, during insertion, the charge 550 may be exposed to a force (e.g, a compressive force from an impact driver). The force may drive the charge 550 towards the first and second thermoplastic laminates 502 and 504, which may cause the retaining piece 554 to compress on the surface of the first thermoplastic laminate 502 and the carbon needles 552 to transfer from the retaining piece 554 into the first and second thermoplastic laminates 502 and 504 at the desired angle. After cessation of the force, the retaining piece 554 may be compressed on the surface of the first thermoplastic laminate 502 and the carbon needles 552 may be substantially disposed within the first and second thermoplastic laminates 502 and504. In some embodiments, the compressed retaining piece 554 and / or portions of the carbon needles 552 residing outside of the thermoplastic laminates may be removed. For example, the portions of the carbon needles 552 residing outside of the thermoplastic laminates 502 and 504 may be trimmed.

[0079] Figure 5C illustrates the welded surfaces 506 of the first and second thermoplastic laminates 502 and 504, and the welded carbon needles 552 with the first and second thermoplastic laminates 502 and 504. In some embodiments, after the carbon needles 552 have been driven into the first and second thermoplastic laminates 502 and 504, it may be desirable to weld the carbon needles 552 with the respective laminates. To weld the carbon needles 552 with the first and second thermoplastic laminates 502 and 504, the heater may heat the thermoplastic structures, including the carbon needles 552, to a specified temperature sufficient to cause the matrix in the carbon needles 552 to interact with the matrices of the first and second thermoplastic laminates 502 and 504. The specified temperature may be based on a material property of the carbon needles 552, the first thermoplastic laminate 502, and / or the second thermoplastic laminate 504. In some embodiments, a material property of the carbon needles 552 is the same as or substantially similar to a material property of either the first and / or second thermoplastic laminates 502 and 504. For example, the matrix used in the carbon needles 552 may be the same as the matrix used in the first and / or second thermoplastic laminates 502 and 504. This may allow the carbon needles 552 to more effectively weld with the respective thermoplastic structures.

[0080] Welding of the carbon needles 552 may serve to fixedly couple the carbon needles 552 with the respective thermoplastic structures, thus mitigating migration. The carbon needles 552 may enhance the ability of the first and second thermoplastic laminates502 and 504 to transfer shear loading. In Figure 5C, the weld between the carbon needles552 and the first and second thermoplastic laminates 502 and 504 is illustrated by the crosshatching on the carbon needles 552.

[0081] In some embodiments, the welded surfaces 506 of the first and second thermoplastic laminates 502 and 504 may occur prior to, during, or after insertion of the carbon needles 552. In some embodiments, an applied load (e.g., from an actuator) assists in forming the welded surfaces 506, while in other embodiments the welded surfaces 506 do not involve the applied load. In some embodiments, the set temperature used to form the welded surfaces 506 may be the same as the temperature used for the welded carbon needles. The welded surfaces 506 together with the welded carbon needles, shown by cross-hatching, may better serve to transfer stresses between the first thermoplastic laminate 502 and the second thermoplastic laminate 504.

[0082] Figure 6 is a flow chart of an example method 600 for joining thermoplastic structures, according to exemplary embodiments of the present invention. In some examples, at least a portion of the thermoplastic structures may be joined by the method 600.

[0083] The method 600 may include one or more operations, or actions as illustrated by one or more steps 602-608. Although the steps are illustrated in a sequential order, these steps may in some instances be performed in parallel, and / or in a different order than those described herein. Also, the various blocks may be combined into fewer steps, divided into additional steps, and / or removed based upon the desired implementation.

[0084] As illustrated, at step 602, the method 600 may include joining thermoplastic structures, by arranging a plurality of thermoplastic structures to form a joint, where the joint has a first side and a second side opposite the first side.

[0085] At step 604, the method 600 may also include joining thermoplastic structures, by positioning a charge over a portion of the joint, where the charge includes a plurality of needles.

[0086] At step 606, the method 600 may also include joining thermoplastic structures, by welding the portion of the joint such that the thermoplastic structures are coupled. The welding includes applying a load to at least the first side of the joint or second side of the joint. The welding also includes heating the portion of the joint.

[0087] At step 608, the method 600 may also include joining thermoplastic structures, by inserting the plurality of needles into the portion of the joint.

[0088] In some embodiments, the method 600 may further include cooling the portion of the joint.

[0089] In some embodiments, the method 600 may further include determining a set process time, a set temperature, and a set impact frequency, where the portion of the joint is heated to the set temperature at a rate of heating defined by the set process time and set temperature, and where the plurality of needles are inserted at a rate of insertion defined by the set process time and set impact frequency.

[0090] In such embodiments, the set process time, the set temperature, and the set impact frequency may be based on a material property of at least one thermoplastic structure of the plurality of thermoplastic structures in the joint.

[0091] In such embodiments, the material property may be a glass transition temperature.

[0092] In such embodiments, the set process time may be based on a thickness of thejoint and a material property of at least one of the plurality of thermoplastic structures.

[0093] In some embodiments, the step of heating the portion of the joint includes heating the portion of the joint via inductive heating

[0094] In some embodiments, the step of inserting the plurality of needles into the portion of the joint further includes determining an impact frequency, where an insertion rate for the plurality of needles is based on the impact frequency, and applying, at the determined impact frequency, an ultrasonic impact to the charge.

[0095] In some embodiments, the charge includes a retaining piece for housing the plurality of needles.

[0096] In such embodiments, the step of inserting the plurality of needles into the portion of the joint includes applying ultrasonic impact to the charge such that as the charge is compressed the plurality of needles transfer from the retaining piece into the portion of the joint, where after the plurality of needles are inserted the retaining piece resides on the first surface.

[0097] In some embodiments, a thermoplastic polymer used in each of the plurality of thermoplastic structures in the joint is the same.

[0098] In some embodiments, a thermoplastic polymer of the plurality of needles is the same as a thermoplastic polymer of at least one of the plurality of thermoplastic structures in the joint.

[0099] In some embodiments, subsequent to inserting the plurality of needles into the portion of the joint, the method 600 may further include welding, using inductive heating, the plurality of needles with the portion of the joint, where a thermoplastic polymer in theplurality of needles is melted to fuse with a thermoplastic polymer in the portion of the joint.

[0100] In some embodiments, prior to inserting the plurality of needles into the portion of the joint, the method 600 may further include providing continuous cooling to the plurality of needles such that the plurality of needles is below a predetermined temperature, where the maximum temperature is based on a material property of the plurality of needles.

[0101] In some embodiments, the plurality of needles are inserted into the portion of the joint at a substantially orthogonal angle to the first side.

[0102] For the method 600 and other processes and operations disclosed herein, the flowchart shows operation of one possible implementation of present examples. In this regard, each step may represent a module, a segment, or a portion of program code, which includes one or more instructions executable by a processor or a controller for implementing specific logical operations or steps in the process. The program code may be stored on any type of computer readable medium or memory, for example, such as a storage device including a disk or hard drive. The computer readable medium may include a non-transitory computer readable medium or memory, for example, such as computer-readable media that stores data for short periods of time like register memory, processor cache and Random Access Memory (RAM). The computer readable medium may also include non-transitory media or memory, such as secondary or persistent long term storage, like read only memory (ROM), optical or magnetic disks, compact-disc read only memory (CD-ROM), for example. The computer readable media may also be any other volatile or non-volatile storage systems. The computer readable medium may be considered a computer readable storage medium, a tangible storage device, or other article of manufacture, for example. In addition, for the method 600 and other processes and operations disclosed herein, one or more steps in Figure6 may represent circuitry or digital logic that is arranged to perform the specific logical operations in the process. This is more fully described in Figure 7 below.

[0103] Figure 7 is a simplified block diagram showing some of the components of an example computing device 700, according to exemplary embodiments of the present invention. In some embodiments, a control panel (e.g., the control panel 106 shown and described with reference to Figure 1) and / or a controller (e.g., the controller 310 shown and described with reference to Figure 3) may include the computing device 700. The computing device 700 may correspond to a computing device configured to perform additional functions (e.g., in communication with one or more other computing devices using a web browser and / or an application). In various embodiments, the computing device 700 may be a mobile computing device (e.g., a smartphone), a desktop computing device, a laptop computing device, a tablet computing device, or a wearable computing device (e.g., a smartwatch or a smart wristband). As illustrated in Figure 7, the computing device 700 may include a network interface 702, a user interface 704, a processor 706, and data storage 708. The network interface 702, the user interface 704, the processor 706, and / or the data storage 708 may be communicatively linked together by a bus 710 (e.g., an electrical interconnect defined on one or more printed circuit boards).

[0104] The network interface 702 may be used by the computing device 700 to communicate with other computing devices over one or more networks (e.g., the public Internet). In some embodiments, the network interface 702 may include a wired interface (e.g., Ethernet). Additionally or alternatively, the network interface 702 may include a wireless interface, such as WIFI. Other interfaces may be included in the network interface 702 and are contemplated herein.

[0105] The user interface 704 may function to allow computing device 700 to receive input from and / or provide output to a user. As such, the user interface 704 may include inputs (e.g., a keypad, a keyboard, a touch-screen, a computer mouse, a microphone, a microphone jack, etc.) and / or outputs (e.g., a cathode-ray tube (CRT) display, a liquid-crystal display (LCD), a light-emitting diode (LED) display, a speaker, a speaker jack, headphones, a headphone jack, etc.).

[0106] The processor 706 may include one or more general purpose processors (e.g., microprocessors) and / or one or more special-purpose processors (e.g., graphics processing units (GPUs) or application-specific integrated circuits (ASICs)). In some embodiments, for example, the processor 706 may include special-purpose processors capable of generating a machine-learned model and / or using a machine-learned model to perform analyses as described herein.

[0107] The data storage 708 may include one or more volatile and / or non-volatile memories. For example, the data storage may include a RAM, a ROM, a hard drive, a solid state drive, etc. In some embodiments, the data storage 708 may be partially or wholly integrated with the processor 706 (e.g., a level 1 (LI) cache or a level 2 (L2) cache within a central processing unit). The data storage 708 may include removable components (e.g., a flash drive) and / or non-removable components (e.g., a ROM integrated with a motherboard).

[0108] The processor 706 may be configured to execute instructions 718 (e.g., compiled or non-compiled program logic and / or machine code) stored in the data storage 708 to carry out the methods described herein. Hence, the data storage 708 may include a non- transitory computer-readable medium, having stored thereon program instructions that, when executed by the processor 706, cause the processor 706 to carry out any of the methods,processes, or operations disclosed in this specification and / or the accompanying drawings. In some embodiments, the processor 706 may use the application data 712 while executing the instructions 718.

[0109] In some embodiments, the instructions 718 may include an operating system 722 (e.g., an operating system kernel, device driver(s), and / or other modules) and one or more applications 720 (e.g., mobile applications, sometimes referred to as “apps”). As described above, the processor 706 may access the application data 712 when executing the applications 720.

[0110] The applications 720 may communicate with the operating system 722 through one or more application programming interfaces (APIs). These APIs may facilitate, for instance, the applications 720 reading and / or writing the application data 712, transmitting or receiving information via the network interface 702, receiving and / or displaying information on the user interface 704, etc.

[0111] Additionally, the applications 720 may be downloadable to the computing device 700 through one or more online application stores or application markets (e.g., using the network interface 702). However, application programs can also be installed on the computing device 700 in other ways, such as via a web browser or through a physical interface (e.g., a universal serial bus (USB) port) on the computing device 700.

[0112] While many of the techniques and functions described herein may be performed by the processor 706 executing one of the applications 720, it understood that other ways for the computing device 700 to perform such techniques and functions are also possible and are contemplated herein. For example, some or all of the calculations may be performed remotely (e.g., on a server computing device). Such an embodiment may bereferred to as a “browser-based app” when the computing device 700 provides data (e.g., application data 712) to a different computing device for analysis using a web browser. Additionally or alternatively, such an interaction between the computing device 700 and another computing device may be performed using an API or a browser-based language (e.g., JavaScript).

[0113] Implementations of the present disclosure can thus relate to one of the example embodiments listed below.

[0114] Embodiment 1 is a method for joining thermoplastic structures, the method comprising: arranging a plurality of thermoplastic structures to form a joint, wherein the joint has a first side and a second side opposite the first side; positioning a charge over a portion of the joint, wherein the charge comprises a plurality of needles; welding the portion of the joint such that the thermoplastic structures are coupled, wherein the welding comprises: applying a load to at least the first side of the joint or second side of the joint, and heating the portion of the joint; inserting the plurality of needles into the portion of the joint.

[0115] Embodiment 2 is the method according to embodiment 1, further comprising cooling the portion of the joint.

[0116] Embodiment 3 is the method according to embodiment 1 or embodiment 2, further comprising determining a set process time, a set temperature, and a set impact frequency, wherein the portion of the joint is heated to the set temperature at a rate of heating defined by the set process time and set temperature, and wherein the plurality of needles are inserted at a rate of insertion defined by the set process time and set impact frequency.

[0117] Embodiment 4 is the method according to any of embodiments 1 to 3, wherein the set process time, the set temperature, and the set impact frequency are based on a materialproperty of at least one thermoplastic structure of the plurality of thermoplastic structures in the joint.

[0118] Embodiment 5 is the method according to any of embodiments 1 to 4, wherein the material property is a glass transition temperature.

[0119] Embodiment 6 is the method according to any of embodiments 1 to 5, wherein the set process time is based on a thickness of the joint and a material property of at least one of the plurality of thermoplastic structures.

[0120] Embodiment 7 is the method according to any of embodiments 1 to 6, wherein heating the portion of the joint comprises heating the portion of the joint via inductive heating.

[0121] Embodiment 8 is the method according to any of embodiments 1 to 7, wherein inserting the plurality of needles into the portion of the joint further comprises: determining an impact frequency, wherein an insertion rate for the plurality of needles is based on the impact frequency; and applying, at the determined impact frequency, an ultrasonic impact to the charge.

[0122] Embodiment 9 is the method according to any of embodiments 1 to 8, wherein the charge further comprises a retaining piece for housing the plurality of needles.

[0123] Embodiment 10 is the method according to any of embodiments 1 to 9, wherein inserting the plurality of needles into the portion of the joint comprises applying ultrasonic impact to the charge such that as the charge is compressed the plurality of needles transfer from the retaining piece into the portion of the joint, and wherein after the plurality of needles are inserted the retaining piece resides on the first surface.

[0124] Embodiment 11 is the method according to any of embodiments 1 to 10, wherein a thermoplastic polymer used in each of the plurality of thermoplastic structures in the joint is the same.

[0125] Embodiment 12 is the method according to any of embodiments 1 to 11, wherein a thermoplastic polymer of the plurality of needles is the same as a thermoplastic polymer of at least one of the plurality of thermoplastic structures in the joint.

[0126] Embodiment 13 is the method according to any of embodiments 1 to 12, wherein subsequent to inserting the plurality of needles into the portion of the joint, the method further comprises welding, using inductive heating, the plurality of needles with the portion of the joint, wherein a thermoplastic polymer in the plurality of needles is melted to fuse with a thermoplastic polymer in the portion of the joint.

[0127] Embodiment 14 is the method according to any of embodiments 1 to 13, wherein prior to inserting the plurality of needles into the portion of the joint, the method further comprises providing continuous cooling to the plurality of needles such that the plurality of needles is below a predetermined temperature, wherein the maximum temperature is based on a material property of the plurality of needles.

[0128] Embodiment 15 is the method according to any of embodiments 1 to 14, wherein the plurality of needles are inserted into the portion of the joint at a substantially orthogonal angle to the first side.

[0129] Embodiment 16 is a device for joining a thermoplastic structure, the device comprising: a frame; an actuator coupled to the frame and configured to apply a load; a heating unit coupled to the frame; an impact driver coupled at a first end to the frame and at a second end to an impact plate, wherein the impact plate drivingly engages a charge, whereinthe charge comprises a retaining piece and a plurality of needles disposed within the retaining piece; and a controller coupled to the frame and configured to: weld a portion of the thermoplastic structure, wherein the welding comprises: apply a load to a side of the portion of the thermoplastic structure, and heat the portion of the thermoplastic structure; and insert, using the impact driver, the charge into the portion of the thermoplastic structure.

[0130] Embodiment 17 is the device according to embodiment 16, further comprising a cooling unit coupled to the frame and configured to provide below ambient temperature air to the charge, such that the plurality of needles are below a maximum temperature in the retaining piece.

[0131] Embodiment 18 is the device according to embodiment 16 or embodiment 17, wherein the controller comprises a control panel configured to input: a set process time; a set temperature; and a set impact frequency.

[0132] Embodiment 19 is the device according to any of embodiments 16 to 18, wherein at least one of the set process time, the set temperature, and the set impact frequency is based on a material property of the thermoplastic structure.

[0133] Embodiment 20 is the device according to any of embodiments 16 to 19, wherein a material property of the plurality of needles is the same as a material property of the thermoplastic structure.

[0134] Embodiment 21 is the device according to any of embodiments 16 to 20, wherein the plurality of needles comprise carbon fiber.

[0135] Embodiment 22 is a robot for joining a thermoplastic structure, the robot comprising: a base; a robotic arm coupled at a first end to the base, the robotic arm having ajoint and movable in six degrees of freedom; a tool coupled to a second end of the robotic arm, the tool comprising: a frame having a first arm and a second arm, the first arm disposed at a distance from the second arm and configured to allow a portion of the thermoplastic structure to be disposed between the first and second arms, an inductive heating unit coupled to the frame, wherein a first portion of the inductive heating unit is coupled to the first arm and a second portion of the inductive heating unit is coupled to the second arm; an impact driver coupled to the first arm of the frame, wherein the impact driver is drivingly engaged with a charge, wherein the charge comprises a plurality of needles, and an actuator coupled to the second arm of the frame and configured to apply a load to the portion of the thermoplastic structure disposed between the first and second arms; and a controller operably connected to the robot and configured to cause the robot to perform the following operations: welding the portion of the thermoplastic structure, wherein the welding comprises: applying, using the actuator, the load to a side of the portion of the thermoplastic structure, and heating, using the inductive heating unit, the portion of the thermoplastic structure to a set temperature; and inserting, using the impact driver, the plurality of needles into the portion of the thermoplastic structure.

[0136] Embodiment 23 is a charge comprising: a plurality of needles; and a retaining piece, compressible between an uncompressed position and a compressed position, wherein the plurality of needles are disposed substantially within the retaining piece at an angle in the uncompressed position, and wherein the plurality of needles are disposed substantially outside of the retaining piece in the compressed position.

[0137] Embodiment 24 is the charge according to embodiment 23, wherein the plurality of needles comprise carbon fiber.

[0138] While the disclosure describes exemplary embodiments related to needling and welding thermoplastic laminates, the systems, methods, and devices described herein may be equally applicable to needling and welding any structure. For example, in some embodiments welding and needling described herein may be performed on a non-composite thermoplastic structure, a thermoset composite structure, and / or a metal structure.

[0139] The above detailed description describes various features and functions of the disclosed systems, devices, and methods with reference to the accompanying figures. In the figures, similar symbols typically identify similar components, unless context dictates otherwise. The example embodiments described herein and in the figures are not meant to be limiting. Other embodiments can be utilized, and other changes can be made, without departing from the scope of the subject matter presented herein. It will be readily understood that the aspects of the present disclosure, as generally described herein, and illustrated in the figures, can be arranged, substituted, combined, separated, and designed in a wide variety of different configurations, all of which are explicitly contemplated herein.

[0140] Further, one or more example features and / or implementations described with respect to a figure may be combinable with one or more example features and / or implementations described with respect another figure and / or figures. Thus, the example features and / or implementations described in each of the figures are not meant to be taken in isolation but may be combinable with any other example feature and / or implementation described above. For example, one or more example features and / or implementations described in any of Figures 1-7 may be combinable with one or more example features and / or implementations described in another figure. Further, unless context suggests otherwise, some but not all of the features and / or implementations illustrated in each of the figures maybe used in combination with one another.

Claims

CLAIMSWhat is claimed is:

1. A method for joining thermoplastic structures, the method comprising: arranging a plurality of thermoplastic structures to form a joint, wherein the joint has a first side and a second side opposite the first side; positioning a charge over a portion of the joint, wherein the charge comprises a plurality of needles; welding the portion of the joint such that the thermoplastic structures are coupled, wherein the welding comprises: applying a load to at least the first side of the joint or second side of the joint, and heating the portion of the joint; and inserting the plurality of needles into the portion of the joint.

2. The method of claim 1, further comprising cooling the portion of the joint.

3. The method of claim 1, further comprising determining a set process time, a set temperature, and a set impact frequency, wherein the portion of the joint is heated to the set temperature at a rate of heating defined by the set process time and set temperature, and wherein the plurality of needles are inserted at a rate of insertion defined by the set process time and set impact frequency.

4. The method of claim 3, wherein the set process time, the set temperature, and the set impact frequency are based on a material property of at least one thermoplasticstructure of the plurality of thermoplastic structures in the joint.

5. The method of claim 4, wherein the material property is a glass transition temperature.

6. The method of claim 3, wherein the set process time is based on a thickness of the joint and a material property of at least one of the plurality of thermoplastic structures.

7. The method of claim 1, wherein heating the portion of the joint comprises heating the portion of the joint via inductive heating.

8. The method of claim 1, wherein inserting the plurality of needles into the portion of the joint further comprises: determining an impact frequency, wherein an insertion rate for the plurality of needles is based on the impact frequency; and applying, at the determined impact frequency, an ultrasonic impact to the charge.

9. The method of claim 1, wherein the charge further comprises a retaining piece for housing the plurality of needles.

10. The method of claim 9, wherein inserting the plurality of needles into the portion of the joint comprises applying ultrasonic impact to the charge such that as the charge is compressed the plurality of needles transfer from the retaining piece into the portion of the joint, and wherein after the plurality of needles are inserted the retaining piece resides on thefirst surface.

11. The method of claim 1, wherein a thermoplastic polymer used in each of the plurality of thermoplastic structures in the joint is the same.

12. The method of claim 1, wherein a thermoplastic polymer of the plurality of needles is the same as a thermoplastic polymer of at least one of the plurality of thermoplastic structures in the joint.

13. The method of claim 1, wherein subsequent to inserting the plurality of needles into the portion of the joint, the method further comprises welding, using inductive heating, the plurality of needles with the portion of the joint, wherein a thermoplastic polymer in the plurality of needles is melted to fuse with a thermoplastic polymer in the portion of the joint.

14. The method of claim 1, wherein prior to inserting the plurality of needles into the portion of the joint, the method further comprises providing continuous cooling to the plurality of needles such that the plurality of needles is below a predetermined temperature, wherein the maximum temperature is based on a material property of the plurality of needles.

15. The method of claim 1, wherein the plurality of needles are inserted into the portion of the joint at a substantially orthogonal angle to the first side.

16. A device for joining a thermoplastic structure, the device comprising:a frame; an actuator coupled to the frame and configured to apply a load; a heating unit coupled to the frame; an impact driver coupled at a first end to the frame and at a second end to an impact plate, wherein the impact plate drivingly engages a charge, wherein the charge comprises a retaining piece and a plurality of needles disposed within the retaining piece; and a controller coupled to the frame and configured to: weld a portion of the thermoplastic structure, wherein the welding comprises: apply a load to a side of the portion of the thermoplastic structure, and heat the portion of the thermoplastic structure; and insert, using the impact driver, the charge into the portion of the thermoplastic structure.

17. The device of claim 16, further comprising a cooling unit coupled to the frame and configured to provide below ambient temperature air to the charge, such that the plurality of needles are below a maximum temperature in the retaining piece.

18. The device of claim 16, wherein the controller comprises a control panel configured to input: a set process time; a set temperature; and a set impact frequency.

19. The device of claim 18, wherein at least one of the set process time, the settemperature, and the set impact frequency is based on a material property of the thermoplastic structure.

20. The device of claim 16, wherein a material property of the plurality of needles is the same as a material property of the thermoplastic structure.

21. The device of claim 16, wherein the plurality of needles comprise carbon fiber.

22. A robot for joining a thermoplastic structure, the robot comprising: a base; a robotic arm coupled at a first end to the base, the robotic arm having a joint and movable in six degrees of freedom; a tool coupled to a second end of the robotic arm, the tool comprising: a frame having a first arm and a second arm, the first arm disposed at a distance from the second arm and configured to allow a portion of the thermoplastic structure to be disposed between the first and second arms, an inductive heating unit coupled to the frame, wherein a first portion of the inductive heating unit is coupled to the first arm and a second portion of the inductive heating unit is coupled to the second arm, an impact driver coupled to the first arm of the frame, wherein the impact driver is drivingly engaged with a charge, wherein the charge comprises a plurality of needles, and an actuator coupled to the second arm of the frame and configured to apply aload to the portion of the thermoplastic structure disposed between the first and second arms; and a controller operably connected to the robot and configured to cause the robot to perform the following operations: welding the portion of the thermoplastic structure, wherein the welding comprises: applying, using the actuator, the load to a side of the portion of the thermoplastic structure, and heating, using the inductive heating unit, the portion of the thermoplastic structure to a set temperature, and inserting, using the impact driver, the plurality of needles into the portion of the thermoplastic structure.

23. A charge comprising: a plurality of needles; and a retaining piece, compressible between an uncompressed position and a compressed position, wherein the plurality of needles are disposed substantially within the retaining piece at an angle in the uncompressed position, and wherein the plurality of needles are disposed substantially outside of the retaining piece in the compressed position.

24. The charge of claim 23, wherein the plurality of needles comprise carbon fiber.

Images