Shear deflections and buckling characteristics of inflated members

The relation between shearing stiffness and inflation pressure is derived by taking into account beam edges and is used in buckling analyses of inflated plates and columns. The drop threads in inflated fabric beams redundantly affect the shear flow in the edges. From experiments on beams of coated metal cloth, it has been concluded from the small transverse curvature that in the flat portion of a beam the shear flow can be disregarded in many practical cases. Shear deflection equations are obtained both with this assumption and with drop threads disregarded. The results are applied to inflated columns by using the Euler criterion modified for shear flexibility. Similarly, conventional theory is extended to cover inflated plates. Eccentrically loaded pressurized-membrane columns are analyzed by modifying the secant formula for shear flexibility and conservatively assuming beam-column collapse to occur when local wrinkling begins.