Gun Launch System Rigid-flexible Coupling Dynamics

The dynamics modeling theory and simulation of a typical rigid-flexiblecoupling system consisted of a multi-rigid-body system, a flexible cantilever beamand a particle moving on the beam is studied in this dissertation.The dynamic problems of the rigid-flexible coupling system are quite differentfrom the dynamic problems of a multi-rigid-body system, in which the complexity isshown as the coupling system between the large overall rigid motion and the smallelastic deformation. Kane studied the elastic beam model with large overall motionand introduced the concept of Dynamic Stiffening. The coupling deformation term,which is produced by the couple of deformation in lognitudinal and in transversedirection, is the key of Dynamic Stiffening.The dynamics of a coupled rigid-flexible weapon launcher is reported. Thecouple rigid-flexible launcher is divided into two subsystems, one is a system of rigidbodies, the other a flexible launch tube which can undergo large overall motionsspatially. First, the mathematical models for these two subsystems were establishedrespectively. Then the dynamic model for the whole system was obtained byconsidering the coupling effect between these two subsystem. The approach reported,which divides a complex system into several simple subsystem fist and then obtainsthe dynamic model for the whole system via combining the existing dynamic modelsfor simple subsystems, can make the modeling procedure efficient and convenient.In this mathematical model the transverse and longitude deformations are allconsidered. This inclusion of coupling deformation can produce the so called dynamicstiffening. Force of friction between the flexible beam and the moving particle isconsidered too.A coupled rigid-flexible rocket launcher is given to validate the presentedmethod and the dynamics of the flexible beams with large overall motions areanalyzed.