2021/07/31 · It can be observed that all rings ( a / t = 200, 400, 500, and 600) are foldable with the same folded configurations (30% of the initial area). For different ring sizes, although a same snapping point ( θ = 0.22 π) is obtained, the stability of folding is largely affected (stable for a / t = 200, unstable for a / t = 400, 500, 600).