Prediction of Postbuckling Characteristics of Perforated Metamaterial Cylindrical Shells Under Axial Compression

Large deflection postbuckling responses of metamaterial cylindrical shells perforated by arrayed circular holes are investigated through a newly proposed theoretical model incorporating with finite element method and experiment.The triggering of an unusual pattern transformation under compressive load(that shows special hyperelastic metamaterial characteristics)contributes to the particularity of the postbucklingmodes,in which the axisymmetric waisted and non-axisymmetric postbuckling configurations of perforated cylindrical shells are identified.The transformations of postbucking modes are mainly affected by global outline sizes of the shell and local geometrical parameters of holes.The structural load-carrying capacity for the waisted postbuckling response suffers a sudden drop and recovers when the holes collapse.Comparatively,the shell would undergo a sustained fall off under non-axisymmetric postbuckling states.The negative Poisson’s ratio induced by pattern transformation plays a key role and a critical effective threshold value exists,inducing the waisted postbuckling mode.The revealed principles would be of benefit for achieving a controllable structural stability that is usually difficult to implement on those conventional structures.