Feasibility Study of Endo- and Exo-skeletal Framed Structures with Envelopes for LTA Platforms

摘要

A pathway for design and fabrication of Endo- and Exoskeleton framed elliptical envelopes was demonstrated. Envelope sizes of 2 ft x 0.5 ft and 5 ft x 1.25 ft were successfully fabricated and their buoyancy and lifting capability were assessed. A technique of filling the envelope with helium was demonstrated. The weight of 2 ft by 0.5 ft envelope before and after filling with helium was 0.082 lb (37 g) and 0.018 lb (8 g), respectively. Using the concepts developed for the 2 ft x 0.5 ft envelope, the fabrication was successfully scaled to 5 ft x 1.25 ft. The weight of the 5 ft x 1.25 ft envelope before filling with helium was 0.48 lb (218 grams). After it was filled with helium the envelope carried a payload of 0.32 lb (143 grams). Frame member sizes are not structurally designed and optimized because the loadings and their conditions were not available, if provided the structure could be designed to meet the optimal operational conditions.