Details

Autor(en) / Beteiligte

• Queral, V.
• Rincón, E.
• Lumsdaine, A.
• Cabrera, S.
• Spong, D.

Titel

Composites and additive manufacturing for high-field coil supports for stellarators

Ist Teil von

• Fusion engineering and design, 2021-08, Vol.169, p.112477, Article 112477

Ort / Verlag

Amsterdam: Elsevier B.V

Erscheinungsjahr

2021

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• •Composites for middle/high field stellarator coil supports.•Finite element calculation of principal directions of stress in the support.•The direction of the (carbon) fibres aligned with the principal directions.•Carbon-fibre epoxy composite satisfactorily layered on (outward) the coils.•Sufficient strength and stiffness of directionally layered composites. The utilization of composites layered on an additive manufactured substrate, for the production of coil supports for modular coils in small or middle size experimental stellarators is assessed. The focus of the study is a monolithic coil support comprising the coils of a half-period of a stellarator, somewhat similar to the ones in UST_2 and ARIES-CS stellarators. However, the concept may be applicable to quasi-monolithic coil supports (coil forms of NCSX type) or individual coil casings (W7-X type). Coil supports for stellarators require high precision, stiffness and strength for large contorted parts. Traditionally, monolithic coil supports are produced by steel casting/forging and final machining. This production method and material gives accurate, stiff and strong coil supports, but the method may be expensive for monolithic supports due to the geometrical complexity and required accuracy of the structure. In relation to those matters, this work investigates whether a monolithic coil support comprising an additive manufactured resin substrate, which is externally (outward from the coils) surrounded with a thick layer of fibre-reinforced resin, may achieve enough strength and stiffness under middle/high magnetic fields. Finite element calculations are produced to obtain the direction of the principal stresses and their values in compression and tension at different areas of the monolithic support, which is relevant for anisotropic materials. The feasibility of directional application of (carbon) fibres on the winding surface of the stellarator outward from the coils is experimentally tested on a scaled-down additively manufactured prototype of a monolithic support. The strength and stiffness of the composite structure appears sufficient for common magnetic fields in experimental stellarators, and the 3D-composite design and manufacturing was technically feasible.