| Metamorphic mechanism is a new type of mechanisms, which is widely used in the fields of manufacturing, aerospace, and bionics. Researches on it are of great significance. In this dissertation, a 3PUS-S(P) metamorphic mechanism is presented, and the kinematics, statics and stiffness of the mechanism are studied. The following works have been accomplished:Firstly, structure model of the 3PUS-S(P) metamorphic mechanism is presented. Changes in topology is analyzed. The freedoms of this mechanism are calculated by Kutzbach-Grubler formulation. The Euller matrix of the mechanism is constructed. The kinematic inverse solution equation of the mechanism is established by combining the exponential product formula. The complete Jacobian matrix of the mechanism is solved based on the screw theory. Based on the principle of virtual work, the mapping between the force screw in the joint space and the operation space is established. The relationship between the evalution index and the geometrical parameters of the mechanism is analyzed, all these analysises lay foundation for the optional design of the mechanism.The driving stiffness matrix and the constrained stiffness matrix of the end of branched chains are constructed according to the synthesis method of substructure. Based on this, the static stiffness model of the 3PUS-S(P) metamorphic mechanism is established. Stiffness distributions at the workspace are gained through the simulation, which lay foundation for the application of this mechanism.Three-dimensional model of the 3PUS-S(P) metamorphic mechanism is accomplished by designing software Pro/E. The ANSYS WORKBENCH finite element analysis software is carried out to solve the model of its linear, angular distortion and mode of vibration. The above-mentioned outcomes lay a solid foundation for the optional design of the 3PUS-S(P) metamorphic mechanism. |
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