Structural optimisation of a bistable deployable scissor module

Bistable deployable scissor structures can be designed to be transportable and can easily be transformed between two stable states, the compact and the deployed state, offering a huge volume expansion. In the deployed state they instantaneously reach structural stability as a consequence of an intended snap-through behaviour during transformation, generated by designed geometric incompatibilities. The design of such structures is ideally based on the duality of taking into account both their nonlinear transformation phase, as well as their service state in the deployed configuration, with opposing requirements. During transformation the peak force - and snap-through magnitude - needs to be minimized to obtain an easily transformable structure, while in the deployed state the stiffness of the structure should be high enough to allow sustaining gravity loads - requiring a high snap-through magnitude. In this contribution the computational design based on these opposing trends is formulated as a multi-objective optimisation approach. The feasibility of the proposed computational optimisation approach is demonstrated on the example of a bistable module.