Modeling and simulation of fiber positioning in composite structures under electro-magnetic agencies

Carbon fibers are electrical conductive and might be magnetically and thermally conductive if particular surface treatment is performed. Due to this effect, the fibers can be deformed by electrical, magnetic and also thermal forces. This can be exploited in the production process of fiber reinforced composites for obtaining different stress distributions at, for example, a hole, and for minimizing the fracture proneness. The numerical treatment of such problems define a challenging task. In this project, we start with single fibers and rovings, which are subjected to a magnetic field. Since the displacements are large, geometrical non-linear effects have to be taken into consideration. The large deformations have, on the other side, a change in the magnetic field, which defines a coupled field problem. Thus, the pure mechanical stiffness has to determined and considered within the finite element computations (treatment of non-linear bar, rope and beam elements with electro-mechanical coupling). From the algorithmic point of view, the Maxwell-equations have to treated, where the external space must be exploited. This can be seen to be very close to fluid-structure interaction problems. In view of large scale examples, homogenized anisotropic problems must be taken into account. 

Apart from these basic investigations, we perform structural computations, where both discrete and continuously distributed reinforcement is led around holes, in order to compare classical drilled holes with the new applications. Thus, the project strongly collaborates with the experimental project on “The realization of potential-based positioning of carbon-fibers in fiber composite structures” and to the project on “Multiscale modeling of functionally conform multiphase composites”.