Simplified aerostructural static model for inflated wings

Asimplified model for analysis of the aerostructural characteristics of multicell baffled inflated wings is presented. The proposed scheme is an iterative procedure based on a beam theory and strip theory that computes the combined stresses due to inflation pressure and due to aeroelastic loading on a multicell wing, accounting for large wing deflections. Wrinkling criterion on the minimal low principal stress and failure criterion on the maximal high principal stress are applied. Together they define envelopes of allowed combinations of inflation pressure and wing loading, or flight dynamic pressure. These envelopes can be generated per wing geometry and material properties and provide guidelines for the design and analysis of inflated wings. The methodology was validated on a single-cell wing, comparing results with analytical failure criteria from the literature. The methodology was then applied to multicell wings of various geometries, studying the effect of wing aspect ratio, wing thickness ratio, and membrane thickness on the allowed wing loading and allowed and required inflation pressure ranges. The methodology enables a preliminary estimate of an inflated wing's performance and can provide a valuable tool for preliminary design and configuration selection.