LAUSR

Abstract This paper describes the first study on the DEMO upper port duct bellows. It aims at establishing the basis for their pre-conceptual design through available standardized analytical procedures and identify the bellows features where the analytical procedures fail and the detailed finite element (FE) analyses are required. The available analytical procedures have been found insufficient for the specific bellows design, considering the rather challenging size, load cases and non-standard trapezoidal shape of the DEMO upper port duct bellows. Although a properly verified design of the bellows cannot be provided at this stage, the development of an optimization tool has been initiated to identify a valid range of bellows parameters that fulfill the design constraints while optimizing their mass or length. The preliminary design results are presented and the shortcomings of the analytical tool identified through FE analyses of bellows performed with the ABAQUS code.