Elastic instability and inflation modeling of an axially-loaded hyperelastic cylindrical thin shell

While inflating the thin-walled hyperelastic cylindrical cell, a localized type of instability occurs. After some deformation, the localization forms a bulge along the tube length. When a bulge reaches a specific diameter, it begins to spread axially. Such a phenomenon occurs at a single pressure value much lower than the pressure required to initiate the bulge. In this paper, we model such a phenomenon by predicting the effect of axial load on the value of limit pressure and bulge propagation pressure. In conjunction with existing experiments, we develop the model and determine the conditions that cause bulges to form and spread in an inflated thin cylindrical shell in the presence of an axial force. Using a newly proposed energy function, we demonstrate how axial tensile load influences bulge initiation and steady-state propagation in a thin cylindrical rubber shell. Experimental data and alternative models have both been used to validate the proposed mathematical model.