Multi-objective optimisation of deployable bistable scissor structures: Fid-Bau Portal

Multi-objective optimisation of deployable bistable scissor structures

Arnouts, L.I.W. / Massart, T.J. / De Temmerman, N. / Berke, P.Z.

Abstract Lightweight bistable deployable structures can be designed to be transportable and reusable. They instantaneously achieve some structural stability when transformed from the compact to the deployed state through a controlled snap-through, as a result of intended geometric incompatibilities between the beams. Due to their transformable bistable nature their design requires assessing both their non-linear transformation behaviour, as well as their service state in the deployed configuration. The requirement of a low peak force during transformation can be shown to oppose the high stiffness requirement in the deployed state; their design can therefore be formulated as a multi-objective non-linear optimisation problem. In this contribution, a size and shape optimisation method is elaborated by choosing the best material combinations, the optimal geometry of the structure and beam cross-sections. The originality of this contribution is the use of a multi-objective evolutionary algorithm to structurally optimise bistable scissor structures taking into account the deployed state as well as the transformation phase. First, the method is applied to optimise a single bistable scissor module. Next, a multi-module bistable scissor structure is optimised and the single module and full structure based approaches are critically compared.

Highlights • A multi-objective optimization approach is proposed for bistable scissor structures; • The optimization incorporates the nonlinear transformation as well as the service state; • The optimization problem is solved using NSGA-II fed by nonlinear FE results; • Pareto fronts are derived for single bistable modules with different materials; • 5x5 modular bistable structures are investigated with different boundary conditions;