Crushing behaviours of folded kirigami structure with square dome shape

In this study, a new type of aluminium sandwich structure with folded square dome as core is proposed. The square dome tessellated core is folded using a single piece of aluminium sheet. Four types of folded dome structures with different base sizes and top face configurations, i.e. 10 mm closed top dome, 20 mm closed top dome, 10 mm open top dome, 20 mm open top dome are studied. A single cube strip model is numerically simulated and calibrated with the experimental results from the previous studies. Good agreement on the peak and average stress between numerical results and test data is achieved. The calibrated model is then used to simulate structural response of the proposed folded dome shape structures. The damage modes and the structural responses including average and peak stress, energy absorption, uniformity ratio and densification strain are compared among these folded structures. The proposed square dome kirigami foldcore shows good energy absorption characteristics under quasi-static loading and dynamic loading by yielding a large densification strain, a low initial peak stress and a small ratio of average stress to peak stress. In addition, unlike the existing cube strip structures, the proposed folded square dome structure shows insensitivity to the crushing speed in terms of initial peak stress and uniformity ratio. Compared with the existing tessellated kirigami foldcore of cube strip, the proposed folded square dome demonstrates a superior performance than most of Miura folded structures.