Initial wrinkling and its evolution of membrane inflated cone in bending

The concept of the wrinkling factor is firstly presented to obtain the wrinkling condition. An extremum method is then proposed to predict the critical wrinkling load and the initial wrinkling location by searching the maximum of the wrinkling factor. Here the critical wrinkling load is defined as the ratio of the wrinkling moment versus the initial wrinkling location, which is different from previous definition. The nondimensional analyses show that the critical wrinkling load and the initial wrinkling location are both closely related to the taper ratio of the inflated cone. The critical taper ratio is 1.5 which corresponds to the highest load-carrying efficiency of the inflated cone in bending. The wrinkled region is finally predicted to deeply understand the wrinkling evolution in the bended membrane inflated cone. A series of wrinkling experiments on the inflated cone in bending are performed to verify the accuracy and the validation of the proposed method. The good agreements between the tests and the predictions give confidence to use the extremum method for wrinkling analysis of the inflated load-carrying structures.