| Flexible bodies with different structure form are widely used in many industrial and technological systems, such as rotary machine, aerospace, vehicle engineering, mechanical arm and micro electro mechanical systems(MEMS). Construction members in these systems undergo large scale rigidity motion as well as elastic deformation. Inertial forces caused by the coupling between the rigid motion and elastic deformation play a key role to the dynamics characteristics for structures. Since that researches to the dynamics on the rigidity-flexible coupling are very important to dynamic analysis, system design and control of flexible multibody system(FMS). Theories on the motion and deformation coupling is a unification between the rigid-body dynamics and the deformable body mechanics. The dynamic formulations developed in this field must take account of the coupling effects between the rigid displacement and the deformation in deformable body, moreover, when ignoring the elastic deformation, the formulation can degenerate to the rigid-body dynamics, and when ignoring the rigid motion, the formulation can degenerate to the deformable body mechanics. There are several research topics which are of current interest, among these topics are the construction for dynamic formulation, computational strategies, impact and contact problem for the FMS and the fluid-structure interaction. Many problems are still not solved completely as a result of the nonlinearity in geometry, motion, Physics and material. Otherwise, the generalized elasticity has been developed deeply in recent years, few research has been given to the generalized elastic body undergoing large scale displacement.The dynamic problem on a single flexible body should firstly be solved, when to formulate the kinetic equation for the FMS. On the base of the research at home and abroad on both the flexible multibody system dynamics(FMD) and generalized elasticity, In this dissertation, we focus on the dynamic formulation for the generalized elastic body undergoing rigid rotating and its computational strategies. The generalized elasticity contains three material parameter is put forward, and the structure with different size scale were analyzed. The dynamic models are developed for the generalized elastic body in the centrifugal field with fixed rotational axis and various rotational speed, also the finite element formulation was derived. The classic rotating cantilever beam is simulated in centrifugal field with both the constant rotational speed and various rotational speed. The main works and conclusions in this dissertation are as follows:①The equations of linear and angular momentum conservation are derived for the generalized elasticity. basing on the couple stress elasticity theory and the micropolar theory. Combining the principle of virtual work with the theorem for the isotropic tensor, the modified relationship was put forward for the couple stress and the curvature tensor, moreover the kinetic equation and the boundary conditions were given for the generalized elastic body.②The finite element equation was formulated for the generalized elastic body, on the base of the method of weighted residuals and the constrained variational principle,with both the displacement and rotational angle considered as independent variables. The 4-nodes and 12-Dofs plane isoparametric element was constructed as well as the 8-nodes and 48-Dofs hexahedron isoparametric element for generalized elastic body. The analysis results to the simple shear problem and the cantilever with different size scale conclude that the generalized elasticity expands the classic elasticity to the micro size scale, and provides much more information than the classic elasticity and the beam theory in the structure analysis.③The dynamic model was developed for the double freedom vibration system, so as to investigate the effects of the centrifugal force, coriolis force and force caused by the eccentricity. For a two-Dofs springmass model, both the float frame reference and the fixed frame reference were introduced to described the motion of the mass point, applying the orthogonal tensor and the Rodriguez rotating formula, the velocity and the acceleration are given, and the dynamics formulation are derived for the fixed axis rotational springmass. The simulation results discovered that the centrifugal force and Coriolis force are play a key role to the dynamic characteristic as well as the eccentricity effect.④The dynamic formulation was constructed for a generalized elastic body rotating along a fixed axis, for the various speed conditions. In the float frame reference, the centrifugal force, Coriolis force and tangential inertial force was investigated. The equations of linear and angular momentum conservation are depicted based on the continuum mechanics analysis method as well as the boundary conditions.⑤The principle of virtual work was adopted to derived the finite element equation for the generalized elastic body in the centrifugal field. The finite element formulation for the classic elastic body undergoing large rigid rotation was also been deduced by the lagrange methods, and the dynamic stiffening effects because of the geometrical non-linearity was discussed in the initial stress methods. The 8-nodes and 48-Dofs hexahedron isoparametric element was extended to the finite element formulation in the motion-deformation coupling simulation for the generalized elastic body.⑥Simulations has been given to a typical cantilever beam rotating around a fixed axis with both the constant speed status and various speed status. Dynamic frequencies and responses for cantilever with different rotating configuration and size scale were evaluated. The results indicate that the dynamic frequencies and responses are different for the different rotating configuration, the dynamic stiffening effect become obviously for the flexible structure in the higher rotating speed conditions, and the size effects can't be ignored when for the micro size structure.
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