FDTD Simulation of Electromagnetic Field, Heat, and Thermal Stress in a ZnO Element for Lightning Currents

Electromagnetic fields, heats, and von Mises stresses in a 37‐mm‐thick ZnO element have been computed with the FDTD method. The FDTD‐computed von Mises stresses ignore shear stresses, but they agree well with those computed with the FEM that considers shear stresses. The FEM‐computed maximum principal stress is almost the same as the FEM‐computed von Mises stress for a current with a duration of 24 μs, but there is about a 30% difference between them for a current with a time to half peak of 100 μs. © 2025 Institute of Electrical Engineers of Japan. Published by Wiley Periodicals LLC.