摘要
Structural vibration modes of large clustered liquid launch vehicles are important criteria for attitude stability design,POGO stability design and structural dynamic load calculation.As the first large one-stage-to-orbit clustered liquid launch vehicle of China,LM-5B has unique structural modal properties which are different from other launch vehicles at home and abroad because of its special structural scheme.Hence,it was necessary to study the structural modal properties for LM-5B.In this paper,ground modal tests for the whole vehicle were conducted to verify and modify the finite-element model of LM-5B,then the structural modal properties were obtained via simulation during flight time,providing significant input for the development of the vehicle.
