Analysis and establishing the equivalent system dynamics model of RRR-RRP II degree bar-group

The equivalent method was combined with FEM in this paper, the equivalent dynamics model for RRR-RRP II degree bar-group was established on the basis of EFEM and the dynamics differential equation was given. Accounting the key point of building dynamic model to be setting up 2 steps tensor T_ia and 3 steps tenser T_ibc and assembling the equivalent mass matrix. The process to establish dynamics model was simple and rapid and the generality is well. Analyzed and solved the dynamics model to the RRR RRP 6 bars mechanism that has been given, the curves of dynamics responding of it was obtained. It is testified by dynamic analysis example that the method presented by this paper has a greater advantage and higher efficiency comparing with traditional method as describing the differential equation and calculating it by using computer and having redeemed the defect that it is easy to make as doing dynamic analysis because of the complexity of kinematics relation of system and the personal skill.