Multi-Material FDTD Modeling of Vehicle Based on CAD Model with ASE Format

It is necessary to distinguish the materials in the electromagnetic simulation model in addition to the accuracy of the geometry. The CAD model of a vehicle contains accurate geometric data and material information. The CAD model is transformed into an ASE format text-readable file. The triangular surfaces data of objects are read to calculate the intersection location with the grid line, and the material number of triangular surface is recorded at the location. The location and material of all the Yee cells are determined one by one, and the multi-material model is constructed. Based on the modeling practice of some vehicles, the general requirements of CAD model for FDTD method are put forward. Two examples of HEMP coupling to vehicle are compared with the software calculation results, and the validity of the multi-material FDTD modeling based on ASE format file is verified. The modeling method presented in this paper can provide reference for the construction of high precision FDTD model.