抄録
Asymmetric laminates of fibrous composites have strong elastic and thermal anisotropic properties, resulting in the curved surfaces caused by residual thermal strain during curing process. Specific asymmetric laminates indicate bi-stable states in terms of surface shapes, and these bi-stable states enable large deformation with relatively small energy input. This becomes an advantage when the asymmetric laminate is applied to the aerospace structures such as a morphing airfoil. The present paper first reveals occurrence criteria of bi-stable states for asymmetric laminates. In-plane buckling strengths are employed as an index of occurrence and calculated for plates with different width-to-thickness ratio and lay-up configurations. Then, vibration properties of bi-stable composite shells are evaluated by using both numerical study with the Ritz method based on Donnel-Mushtari theory and the experimental modal analysis technique. The numerical and experimental results show that there are some relations between the buckling strength and the occurrence of bi-stable states within plates having specific lay-up configurations, and asymmetric laminates with bi-stable states indicate different vibration characteristics before and after snap-thorough deformation.
