FE analyses and tests in support of Wendelstein 7-X trim coil development

Abstract

The paper presents an overview of the finite element (FE) analyses on the trim coils (TCs) and tests performed at IPP, and focuses on some specific aspects of the TC assembly. Global FE models (GM) of two types of TCs predicted the coil deformations and reaction forces on the supports. Dead weight, temperature rise during operation up to 80°C, electromagnetic loads of 19 field configurations, and outer vessel (OV) deformations have been taken into account. In addition, local models were created for the critical winding pack (WP) regions as well as for each support clamp, and were analyzed with boundary conditions determined by the GM. The detailed WP sub-models were developed to verify the insulation strength against local stresses. The simulations were supported by various mechanical tests under static and cyclic loads. Aim of these experiments was to determine the time dependent behavior of the silicone rubber pads which are used as interfaces between TC and supports, and to check and optimize the assembly tools as well as procedures for the TCs and their supports.