Poloidal field coil stress analysis for the ZTH machine

Three-dimensional finite element analysis of representative equilibrium field and ohmic heating coils for the Los Alamos ZTH air core machine was performed to determine static stress levels developed within the coil structure caused by Lorentz-force loading. Because of the complex coil configuration in cross section (copper conductors embedded in an epoxy insulating matrix), the study was performed in three steps: a bulk orthotropic material property determination, a bulk material coil section analysis, and a detailed composite cross section of selected thickness analysis. Computational procedures used with coil stress and displacement results that were obtained are presented. Extensive work was performed to investigate the magnitude of the error in coil stress predictions arising from the use of the three-step analysis procedure. Analytical and numerical procedures used to perform the estimate of error study are also presented. 34 figs