Determination of electromagnetic forces in tokamak magnets using the TORMAC Computer Program

The TORMAC Computer Program has been developed to determine electromagnetic forces for use in the structural analysis of tokamak magnet structural systems. This program has been written for use in a time-share environment on the DEC-10 computer system and prepares output force data in the form of bulk data card images as required for input by the NASTRAN Finite Element Structural Analysis System. The TORMAC Program utilizes a simplified filament method in its computational procedure. Magnets can be defined as an assemblage of inter-connected line elements representing toroidal field (TF) coils or arbitrary extra coils, or complete circular coils representing poloidal field (PF) coils. All TF coils and extra coils are developed to be directly compatible with NASTRAN finite element models. Only one TF coil need be defined with all other TF coils located internally to the program. The extra coils are located relative to the initially defined TF coil and may be used to represent discrete coils unsymmetrically placed relative to the axis of the torus. The circular PF coils must be symmetric with respect to the axis of the torus. In addition to computing electromagnetic forces at the end nodes of each TF coil and extra coil filament, electromagnetic fields are computed at each such filament as well as at a set of extra points defined in the region of each TF coil. A feature is included wherein arbitrary currents may be defined for each TF coil thus permitting the evaluation of fault conditions. Another optional feature is included to present output force data in a form compatible with the analysis of half or quarter symmetric structures. Examples are presented illustrating the use of this program during the structural analysis of tokamak devices currently being developed