Analysis of influencing factors on the achievability of bistable fully closed shells by semi-analytical modelling

Abstract

Bistable fully closed shells can serve as long supporting structures that can be folded into a compact transport geometry and unfolded at the construction place. Bistability is achieved by introducing a specific distribution of residual stresses through the thickness of the shell, e.g. by incremental die-bending. In order to find a suitable bending radii combination a semi-analytical model was developed and experimentally validated for the steel 1.1274 in previous research. Nevertheless, minor deviations have occurred in the prediction of final curvatures of the different stable geometries and it is still unclear to what extent other influencing variables such as shell thickness or material properties influence the achievability of fully closed bistable shells. Therefore, in this paper, an enhancement and generalization of the existing semi-analytical model for different steels is described and the extended model is used for a comprehensive analysis of the influence of different variables on bistability and final shell geometries.