Bi-stable analysis of strain hardening shells

Bi-stable structure can be stable in both its extended and coiled forms. For a thin shell, the plastic forming process leads to the distribution of residual stresses that cause bi-stable behavior. The associated stress distributions are analyzed, assuming a strain hardening material model, and analytical expressions for the distribution of residual stresses and stain energies of the shells in the two stable configurations are obtained. The theoretical results of the curvatures characterizing the bi-stability agree well with the test results.