GLOBAL-LOCAL ANALYSIS OF LARGE-SCALE COMPOSITE STRUCTURES USING FINITE-ELEMENT METHODS

Large domain design problems using finite element methods (FEM) requir e special techniques to achieve solutions within reasonable computatio nal time. Global-local FEM refers to a set of numerical techniques des igned to reduce the total solution time (and therefore the computation al effort) for a given level of solution accuracy. In this paper we ad dress the solution to large-scale periodic structures made up of multi -material composite systems, using two different global-local techniqu es. An error analysis is performed where the spatial distribution of e rrors due to material discontinuities and numerical solution procedure s are evaluated for both of the methods. A simple illustrative example is used in which the error is quantified in relation to the savings i n computational time. The two methods are then applied to the design o f a high-field hybrid magnet, an axi-symmetric composite structure mad e up of a periodic array of ''unit cells''.