Qn the Stress Analysis and the Shape Design of the Scientific Balloon at High Altitude

An analysis of the stress of the zero pressure balloon membrance with rotational symmetry is presented, and the reasonable shapes can be designed by choosing rational restrain conditions of the latitude stress t. We propose the following three principles for σ_t: (1) in the lower hemilballoon,σ_t≈0;(2) then, σ_t gradually increases from the middle to the top of the balloon; (3) near the top, the longitude stress σ_t≈0.According to these principles, one can design balloons with or without reinforce tapes, both have the maximum stress and the total stress energy much less than that in ordinary designs with σ_t=0. So., such types wiljl be adopted in the design of giant ballootn.