Modeling of induction heating of thermoplastic composites

Abstract

In this article, a hybrid finite element model is presented for the simulation of induction heating of layered composite plates. Modeling includes the alternating electromagnetic field generated by an alternating current running through a coil, the current densities in the composite plate resulting from the electromagnetic field, the heat generation resulting from the current density distribution, and the heat transfer resulting from the nonuniform heat generation in the plate and the temperature distribution in the plate. The different elements of the model are shown to capture the time-dependent temperature distribution resulting from a coil moving over the surface of a composite laminate.

Heating mechanisms in induction welding of thermoplastic composites

“…A brief overview of the theory and implementation of the in-house developed toolbox WelDone is discussed here, however, the authors recommend the reader to consult 8,9 for a more detailed explanation of the numerical toolbox, and for experimental validation work.…”

“…The electrical conductivity values were determined by measuring the resistivity for consolidated unidirectional (UD) laminate consisting of only 0 layers in the 1-, 2-, and 3-direction. As discussed in [7][8][9] different ply orientations within a laminate are required to generate heat when using induction welding. For each ply, the electrical conductivity tensor was rotated by the ply orientation angle using:…”

“…1 The selected method to fusion bond the thermoplastic composites in this research is induction welding as it has multiple benefits when compared to resistance and ultrasonic welding: (i) no contact between the heating element and part is required; and (ii) no need for susceptors when using CFRTP with plies in different orientation. 2 The principle behind induction welding is explained by various researchers and groups in literature, [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18] however, a brief explanation is given here for the reader's convenience. To induction weld, an alternating-current (AC) flows through a coil, this produces an alternating electromagnetic (EM) field in and around the coil (as discussed by Faraday's law) including the CFRTP parts.…”

“…4 At the start of this research it was unclear which, or which combination of the three heating mechanisms would dominate. Literature does not provide a clear answer to this question, some literature [10][11][12][16][17][18] suggest fiber-to-fiber contact heating playing a significant role while other literature 4,5,[7][8][9][13][14][15] indicate differently, and point toward the resistivity of the fiber and polymer. This manuscript, therefore, aims to clarify which heating mechanism or which combinations of mechanism are dominant using laminatelevel and fiber level numerical simulations.…”

“…The principle behind induction welding is explained by various researchers and groups in literature, 1–18 however, a brief explanation is given here for the reader’s convenience. To induction weld, an alternating-current (AC) flows through a coil, this produces an alternating electromagnetic (EM) field in and around the coil (as discussed by Faraday’s law) including the CFRTP parts.…”