Structural Integrity of Hasty Aircraft Inflatable Large Shelters (HAILS) Under Wind Loads

Abstract

Hasty aircraft inflatable large shelters (HAILS) are lightweight, long spanning, cost efficient, easily transported, and easily erected structures. However, these flexible membrane structures are susceptible to large deformations and structural collapse due to wind loads. A HAILS prototype has been analyzed via finite element modeling in ANSYS Mechanical over a range of wind speeds ranging from 0 mph to 90 mph using ASCE 7-16 wind pressure coefficients. The structure was analyzed at its maximum and minimum inflation pressures of 0.5 psi and 0.22 psi, respectively. Membrane specimens from the HAILS prototype were tested to determine nonlinear stress-strain behavior and ultimate strength. Maximum stresses were found in the analysis to determine if tensile rupture were possible during a 90-mph wind event, while minimum stresses were found to determine if structural collapse were possible. Uplift and shear forces were determined for anchor testing in a separate study. This study shows that without any manufacturing defects the HAILS prototype should be able to withstand a 90-mph windstorm without the appearance of wrinkling or collapse of the cross-section.