A nonconformal FETI method with a reduced global interface system

This paper presents a nonconformal finite element tearing and interconnecting (FETI) method where the dual unknown is expanded by modal fields. With this modal expansion, the number of dual unknowns can be reduced significantly, thus reducing the size of the global interface system. Scattering analysis of a deep cavity is adopted to illustrate the application of the method. Its accuracy and efficiency are validated by calculating the monostatic radar cross section of a rectangular cavity.