An In-Bore Projectile and a Flexible Tube Seen as a Superelement in Launch Dynamics Using Reduced Multibody System Transfer Matrix Method

Launch dynamics of multibody systems (LDMS) studies the forces and motions of the rigid-flexible coupled multibody system composed of an artillery and a projectile during the launch process. In the authors’ previous work, the marching fire of LDMS where the launching carrier experiences a large overall motion in space is simulated, with the artillery being formulated by the multibody system transfer matrix method (MSTMM) and the projectile by the Newton–Euler method. However, such a hybrid formulation does not facilitate the study of LDMS. In this paper, the marching fire of LDMS is formulated in a unified framework of the reduced MSTMM. This is achieved by treating the flexible tube and the rigid projectile as a superelement and deducing the reduced transformation at the output end O of the superelement. The kinematics and kinetics of the superelement are analyzed and then used as basic equations for such deduction. The derived reduced transformation fits for launching subsystem with marching fire including rocket-launcher, and projectile-artillery with or without rifling.