Effect of wrinkling deformation on the wind-induced responses of inflated membranes

Inflated membranes are a kind of flexible structure very sensitive to wind load. The enveloping membrane is prone to be wrinkled under compression with very small stiffness and stresses in the direction perpendicular to wrinkles, resulting in a significant change in the wind-induced responses of the inflated membrane. This paper studies the effect of wrinkling deformation on the dynamic behavior of inflated membranes under wind. A thin shell model with random imperfection is developed based on the stability theory to consider the wrinkling deformation of the enveloping membrane. The internal air is treated as a kind of potential-based fluid to consider the air-membrane interaction. The governing equations of inflated membranes are discretized with the finite element method. Square ETFE cushions under the time history of wind pressure provided by the TPU database are analyzed with the developed finite element model for different initial internal pressures and wind speeds to investigate the effect of wrinkling deformation. The results indicate that: a) Effect of the wrinkling deformation is larger on the windward side and smaller on the leeward side with largest magnitudes on the corners; b) The wrinkling deformation has a larger effect on the stresses with more sensitivity to the varying initial internal pressure and wind speed on the windward side; and c) Effect of the wrinkling deformation decreases with the increasing initial internal pressure and increases with the growing wind speed. The present research is helpful to the understanding of the effect of wrinkling deformation on the dynamic behavior of inflated membranes under wind for their rational design and reliable engineering application.