Snap-through and stiffness adaptation of a multi-stable Kirigami composite module

Multi-stable composite laminates have been used to create adaptive and shape-morphing structures for many applications. However, it remains challenging to use these composites to obtain complicated shape changes and mechanical property adaptations. This study proposes a Kirigami composite concept to help address this challenge. By strategically placing slit cuts into the composite laminate with carefully designed fiber layout, one can release the internal constraints and significantly enrich the achievable shapes and adaptive functions. This study focuses on the elementary Kirigami composite module consisting of a single slit cut and two bistable patches. Experiments and finite element simulations show that this Kirigami module exhibits four different stable equilibria and its snap-through instability originates from a rapid run-away growth of surface curvature inversions due to connecting tab. This study also investigates a stiffness adaptation function. These results can be used for creating more sophisticated Kirigami composite structures with multiple patches and cuts.