Research On Recursive Dynamics Of Rigid-Flexible-Liquid Coupling Mechanical Multibody Systems

With the development of technology, there are large numbers of rigid-flexible-liqued couplingmultibody system in the field of aerospace, vehicles and robot. To solve these kinds of problems, thespatial operator algebra theory of rigid-flexible coulping and considering small amplitude liquidsloshing multibody system are deduced as well as the solving method of multibody system dynamicsbased on Interval Arithmetic is obtained. The main content of this thesis include five aspects:(1)To meet the demand of improving calculate velocity and precision during the developmentprocess of multibody system dynamics, the spatial operator algebra theory, Lie Groups and Liealgebraic method and the recursive Hamilton dynamics equations which are most important of O(n)times dynamics computational efficiency are summarized. Meanwhile, the dynamics of rod linkagesis deduced by multibody system dynamics method described by fully cartesian coordinate.(2)The dynamics of flexible multibody system is studied. Firstly, the flexible object is treated asapproximate rigid object, the Mathematical modeling for this approximate rigid object is founded bythe finite segment method and the flexible multibody system is dynamical analyzed by spatialoperator algebra theory. Next, the rigid-flexible coupling multibody system dynamics is modeled,meanwhile, the numerical code for this system which is based on Mathematical software is obtained.Finally, the calculational procedure is compared between the spatial operator algebra dynamicsmodeling and tradition Lagrange modeling method by a calculating case.(3)The dynamic characteristic of liquid-filled tank is researched by spatial operator algebratheory. The force expression for the tank and liquid is obtained by the momentum theorem and themomentum moment theorem. The mode of liquid sloshing is achieved by Finite element modalanalysis and the mode results are utilized for the recursive dynamics modeling of small amplitudeliquid sloshing multibody system which is accomplished by spatial operator algebra theory. Thedynamic calculational procedure for small amplitude liquid sloshing multibody system is achieved byMathematical software.(4)The study on the problem of multibody system dynamics is deduced by Interval Arithmetic.Based on the Newmark method and Interval Arithmetic to solve the multibody system dynamicsdifferential equations and the spatial operator algebra theory modeling with underactuated jointsystem. The corresponding numerical computation program is compiled. The specific example is usedto demonstrate the effectiveness and correctness for the new algorithm. (5) Based on natural orthogonal complement and decoupling of natural orthogonal complement,the recursive dynamics for the closed loop systems are discussed. A new plane cam reducer such assimple parallel cam reducer and planetary cam reducer are designed and the cam curve are designedby means of divided degree and divided segment method for the conjugate cams. The dynamiccharacteristic of these two reducers is studied by Virtual Prototyping Technology based on recuisivedynamics.