Systems and methods are provided for controlling welding. One embodiment is a method for controlling welding. The method includes initiating induction welding by operating an induction coil along a weld interface of a first composite part comprising a matrix of thermoplastic reinforced by fibers, in order to join the first composite part to a second composite part, determining a measured magnetic field strength at a location distinct from the induction coil, and determining a welding temperature at the weld interface of the first composite part based on the measured magnetic field strength.

Systems and methods are provided for controlling welding. One embodiment is a method for controlling welding of a composite part. The method includes locating a linear fiber optic sensor along a composite part comprising a matrix of thermoplastic reinforced by fibers, measuring temperatures along the weld line via the linear fiber optic sensor, performing induction welding at the composite part along the weld line, determining a continuum of weld temperatures along the weld line, and controlling the induction welding based on the continuum of weld temperatures.

A heat sink for use in induction welding includes a number of tiles, wherein the tiles are electrically non-conductive and have a thermal diffusivity of greater than about 25 mm2/sec. A joint flexibly joins the tiles together.

A method of induction welding a first thermoplastic composite (TPC) to a second thermoplastic composite (TPC) using an induction coil includes forming a weld interface area between the first TPC and the second TPC, cooling the first TPC with a cooling apparatus before heating by the induction coil, and inductively heating the weld interface area with the induction coil after cooling the first TPC.

A method of joining workpieces includes the steps of bringing a first workpiece and a second workpiece together, induction heating a susceptor material, and pressing the workpieces together. Each workpiece may include a thermoplastic material, and the workpieces are brought together at a joint interface so that a protrusion of the first workpiece is aligned with a receptacle of the second workpiece. The susceptor material is in contact with the thermoplastic material of the first workpiece during heating such that the thermoplastic material of the first workpiece softens. The step of pressing is performed while the thermoplastic material of the first workpiece is softened, thereby reshaping the first workpiece where the susceptor material is in contact with the thermoplastic material of the first workpiece. The protrusion is deformed to form an interlock with the receptacle at the joint interface.

A heat sink for use in induction welding includes a flexible backing and a number of tiles disposed on the flexible backing in a single layer, wherein the tiles are electrically non-conductive and thermally conductive.

A heat sink for use in induction welding includes a number of tiles, where the tiles are electrically non-conductive and thermally conductive, a joint flexibly joining the tiles together, and a fluid path formed through the heat sink for communicating a coolant therethrough.

A method of dissipating heat from a surface of a first thermoplastic composite (TPC) being inductively welded with a second thermoplastic composite (TPC) includes flexing a heat sink during placement to conform to the surface of the first TPC, cooling the heat sink, applying inductive heat to a weld interface area between the first TPC and the second TPC, and drawing off heat via the heat sink from the surface of the first TPC.

A method of joining workpieces includes the steps of bringing a first workpiece and a second workpiece together, induction heating a susceptor material, and pressing the workpieces together. Each workpiece may include a thermoplastic material, and the workpieces are brought together at a joint interface so that a protrusion of the first workpiece is aligned with a receptacle of the second workpiece. The susceptor material is in contact with the thermoplastic material of the first workpiece during heating such that the thermoplastic material of the first workpiece softens. The step of pressing is performed while the thermoplastic material of the first workpiece is softened, thereby reshaping the first workpiece where the susceptor material is in contact with the thermoplastic material of the first workpiece. The protrusion is deformed to form an interlock with the receptacle at the joint interface.

A portable welding device comprising: a base facing a work surface, designed to receive tapes in electrically conductive composite materials to be joined or defined by at least one already positioned tape; an operating head receiving one tape at a time and movable with respect to the base along at least a first movement line parallel to the work surface; a motorized arm connecting the operating head to the base and selectively activatable to impart movements to the operating head; and feeding means selectively activatable to feed one tape at a time to the operating head and connected to the operating head; the operating head comprises a positioning roller receiving a tape at a time; a pressure roller spaced from and aligned with the positioning roller along the first movement line; and an inductor interposed between the positioning roller and the pressure roller with reference to the first movement line.