Engineering Analyses of NCSX Modular Coil and Its Supporting Structure for EM Loads
Authors: H.M. Fan and D. Williamson
Date of PPPL Report: October 2003
Presented at: the 20th IEEE/NPSS Symposium on Fusion Engineering (SOFE2003), 14-17 October 2003, San Diego, California. Proceedings to be published by IEEE.
NCSX modular coil is a major part of the NCSX coil systems that surround the highly shaped plasma and vacuum vessel. The flexible copper cable conductors are used to form modular coil on both sides of the 'tee' beam, which is cast inside the supporting shell structure. The engineering analyses comprise sequentially coupled-field analyses that include an electromagnetic analysis to calculate the magnetic fields and EM forces, and a structural analysis to evaluate the structural responses. In the sequential EM-structural analysis, nodal forces obtained from the EM analysis were applied as "nodal force" loads in the subsequent stress analysis using the identical nodal points and elements. The shell model was imported directly from Pro/ENGINEER files in order to obtain an accurate structural representation. The Boolean operations provided by the ANSYS preprocessor were then applied to subdivide the solid model for more desirable finite element meshing. Material properties of the modular coil were based on test results. Analyses using the ANSYS program to evaluate structural responses of the complicated modular coil systems provided a clear understanding of the structural behaviors and the directions for improving the structural design.