Three-dimensional electromagnetic modeling of composite dielectric materials

When manufacturing composite dielectric materials with various shapes, sizes, dielectric properties, and amounts of each constituent element, it is beneficial to predict the effective dielectric constant and the distribution of electric fields within the composite. A three-dimensional electromagnetic model has recently been developed at the University of Missouri to aid in this analysis. CST EM Studio, which specializes in three-dimensional electromagnetic simulation, was chosen for the simulation environment. A custom-developed software program automates the construction and electromagnetic analysis of the composite material within CST EM Studio. The program virtually constructs a composite with up to thousands of distinct composite elements placed in a quasi-random arrangement according to user-defined input parameters. The program provides a means of efficiently and accurately modeling composite systems without manually creating the high number of individual composite elements. The program enables user specification over the simulation parameters and automated analysis of the simulation results through a user interface. The dielectric constant of each composite element, the loading percentages, and multiple physical particle parameters, including the shape, size, and density, are user-defined. The effective dielectric constant of the composite is determined by analyzing the capacitance of a parallel plate capacitor made with the virtual composite material. Additionally, the distribution of electric fields through the composite elements and at potential triple points can be analyzed for potential sites of failure. A detailed description of the modeling method and program is provided. Commonly-used equations for the effective dielectric constant of composites are introduced, and comparisons are presented between the simulated effective dielectric constant and the values calculated from those equations for various particle loading percentages. Lastly, examples of how the electric field is distributed through the composite structure are included.