Analysis of mechanical dynamometer based on bifurcation theory

摘要

In order to study the nonlinear characteristics of a mechanical dynamometer, a mathematic model isestablished using the Lagrangian method. The adequate and essential conditions for homoclinic orbit and periodical orbit of the system are discussed using the model. A bifurcation diagram of the external excitation is obtained through simulation. Simulation through the quasi-periodic route; Poincare sections and phase portraits validate the doubling bifurcation motion of the system. Therefore, typical nonlinear vibration can be found in this system, especially when the excitation frequency is changing between its lower and higher values. For the purpose of improving the measuring accuracy, the parameters of the mechanical dynamometer should be designed to keep the system in periodic and quasi-periodic motions.