Optimum Cable Configuration for Air-Supported Structures

It is anticipated that the design of large-span air-supported structures will increasingly rely on a two-way system of reinforcing cables to provide the overall structural integrity. This report makes recommendations on the optimum shape for such reinforcing cable networks if the deflections and cable forces are to be minimized. It is proposed that this optimum will comprise cables that follow lines of initial geodesic curvature and will therefore maintain constant tension along their lengths. Examination of numerical results for a spherical cap and a part-circular cylinder under lateral loading support this proposal and confirm the advantages of geodesic networks over networks that follow lines of principal curvature. Numerical results are obtained with the use of an iterative computer program based on previous work and adapted for the solution of tension-only structures. Consideration of the numerical difficulties encountered with this class of structure is included.