Co-Simulation research on envelope structure of an umbrella-like inflated airship in near space

The composition and principle of the envelope structure of an umbrella-like inflated airship in near space are firstly introduced in this paper. An improved design scheme of the envelope retractable mechanism is put forward to solve the stress concentration problem in the original envelope retractable mechanism. And then a flexible multi-body dynamics analysis based on the improved envelope retractable mechanism is carried out to obtain the displacement function with time of connection panels. Then a finite element analysis of the envelope structure at altitude of 20 km is used to get the stress distribution on the envelope surface and the tension force transferred to connection panels. Finally, a collaborative simulation method of flexible multi-body dynamics analysis and finite element analysis is put forward. By means of this method, the load history of the maximal force-applied rod in the envelope retractable mechanism during the whole deformation process is obtained, and a comparison of load histories of the rods between the improved envelope retractable mechanism and the original one is demonstrated to verify the rationality of the improved envelope retractable mechanism.