Abstract: In this paper, based upon the characteristics of elastic modal combination of large solid bundled launch vehicles, the finite element theory is used to describe the complex elastic vibration of a solid bundled launch vehicle, and a new three-channel unified elastic vibration equation was established. The elastic vibration equation can reflect the coupling between channels and between boosters and core stage. Some issues need consideration in the theoretical derivation, an engineering application was proposed, and the elastic vibration model was verified. The results of the theoretical derivation and simulation show that the elastic vibration equation of a solid bundled launch vehicle established in the paper is correct and can meet the needs for the engineering application.

Key words: font-size:15px, background-color:#FAFAFA, ">solid bundled rocket, finite element, elastic vibration, coupling