Bi-stable Mechanical Behaviors of Double-layered Isotropic Shell Structure

Bi-stable structures are usually made of laminated composite materials.However,composite materials have inherent shortcomings,e.g.,laminated plates of symmetrical lay-up can twist when bending;laminated plates of anti-symmetrical lay-up are easily liable to temperature.In contrast,isotropic structures have no bending-stretching and twisting-bending coupling.A pre-stressed double-layered isotropic cylindrical shell model is proposed in this paper.Expressions for the bending and stretching strain energies are presented.Calculations show that total strain energy has two local minimum values,which reveals that the cylinder shell structure has its bi-stability.The corresponding rolled-up radius is thus determined.Meanwhile,FEM simulation on the bi-stable processes has been performed,and numerical data coincide with well the predicted results by the proposed model.