Double-layer cylindrical shell was studied.ANSYS was secondarily developed by APDL

and automatically modeling

loading

adding constraints and solving of double-layer cylindrical shell with random span have been carried out.Mode and transient analysis has been analyzed based on it.The characteristics of structural natural vibration was firstly analyzed according to geometrical parameters

and natural frequency’s rule of structure has been studied according to ratio of rise to span and shell thickness.The result show that the stiffness is larger when ratio of rise to span is between 1/5 to 1/3.6 and thickness is among 1.8 m to 2.4 m;Dynamic internal force of bars will increase along with increasing thickness and constant ratio of rise to span

and the dynamic internal force ratio of two-dimensional to one-dimensional also increase more or less

but the bar’s force in longitudinal direction changed insignificantly.Time response curves of maximal displacement and axial stress have been drawn under seismic effect

and seismic performance of the shell has been derived.