Shape Memory Effects in Polymer Composites by Temperature Control Through Electromagnetic Induction Heating by Employing a Weakly Coupled Multi-Physics Multi-Timescale Model

Shape memory behavior refers to the ability of the material to shift from a
temporary configuration to the permanent/original configuration under the
influence of an external stimulus, such as temperature, electromagnetism, and
light. Triggering the shape change in polymer composites through contactless
temperature control induced through the losses incurred by the high frequency
alternating electromagnetic fields is the primary focus of this work.
A multi-physics electro-magneto-thermo-mechanical (EM-TM) model
employing mixed-FEM formulation with nodal and Nédélec’s edge elements
was developed for dynamic EM problems coupled with finite TM deformations.
An efficient timescale coupling technique weakly coupling the respective multi-
physics: the EM problem (at a timescale proportional to the high frequency of
the electromagnetic source) and the TM problem, was developed and applied.
A finite strain phenomenological model for shape memory behavior of semi-
crystalline polymers under thermo-mechanical loading was recently developed
in-house (H. Gülaşik, M. P. Muñoz, and L. Noels, “A Thermo-Mechanical,
Viscoelasto-plastic Model for Shape Memory Polymers”, in preparation). The
visco-elasto-plastic constitutive model for the thermo-mechanics of the shape
memory polymer is extended considering: i) weak coupling with the dynamic
EM problem by employing the multi-timescale coupling ii) the heat source
arising from the losses incurred by the alternating EM fields. The developed
weak coupling algorithm accounts for the large deformations in the polymer
while computing the EM fields and the EM heat source by a) remeshing the
geometry used in the EM problem by importing the deformed configuration
from the TM problem b) transfer of the relevant fields with appropriate
kinematic transformations between the deformed and the reference
configuration.
Shape memory effects with shape fixity, shape recovery, and phase transition
achieved by controlling the temperature in the polymer through EM sources will
be demonstrated by numerical test results.