Bistable Characteristics of Irregular Anti-symmetric Lay-up Composite Cylindrical Shells

The bistable characteristics of the irregular anti-symmetric cylindrical shell (IACS), such as [+α₁/ -α₂/ +α₂/ -α₁] lay-up, are presented using theoretical methodology and finite element (FE) analysis. A novel approach named two points loading method is used to induce a snap-through of the shell in FE analysis. Unlike regular [+α/ -α/ +α/ -α] lay-up anti-symmetric cylindrical shells, two or more different ply angles are included in the irregular anti-symmetric lay-up. Besides ply angles, the bistable characteristics of composite cylindrical shells with irregular anti-symmetric lay-ups are also affected by the sequence of lay-ups. Both analytical and FE results show that IACS with different bistable behaviors can be obtained by changing the ply angles or sequence of the lay-ups. It is very useful for the design and manufacture of the bistable structure. There is a reasonable agreement between analytical and FE predictions; possible reasons of differences between analytical and FE results are given.