Load Introduction into Pressurized Films.

摘要

This report presents a numerical method for predicting the distribution of stresses in a superpressure balloon system manufactured from a homogeneous,isotropic,elastic film sufficiently pressurized to prevent geometric instabilities. A computational model of the problem was established in the area of load attachment by considering a rectangular region subjected only to an in-plane load at the corner and neglecting any effects of curvature. The grid size is sufficient to obtain detailed stress distributions in and around seams and load patches. Results are presented for two particular load patches as well as the stresses associated with three different seam to film stiffness ratios. As expected the results indicated the most highly stressed region to be in the vicinity of load introduction. The magnitude of these stresses is acceptable but dependent on the payload being supported uniformly by all load lines. The results also indicate that some load is retained in the seam,the amount dependent on the ratio of seam to film stiffness.