Abstract: The dynamic modeling of compliant mechanism becomes more difficult and complex because of the geometric nonlinear factor resulted by the large deformation of flexible beam. In order to solve this problem, based on the simplification principle, a new method for its dynamic modeling is studied with the consideration of large deformation character of flexible beam. Three kinds of flexible beams, i.e. end-moment, end-vertical force and parallel-guided mode are considered as research objects. With the consideration of large deformation characteristic and in the combination of boundary condition obtained from the pseudo rigid-body model, deformation curve of flexible beam under large deformation is obtained on the basis of the least square principle. And the kinetic energy of flexible beam is deduced. Based on the principle of energy conservation, the potential energy of flexible beam is easily calculated in the pseudo rigid body model. Then the dynamic model of parallel guided compliant mechanism is developed. Finally, the numerical analysis verifies the validity of the dynamic model by comparing with other methods.

Key words: Compliant mechanism, Dynamic model, Pseudo rigid body model