Studies On Non-Linear Dynamics Of A Multi-Degree-of-Freedom Viscoelastic Drive Belt System

Viscoelastic drive belt systems transmit the power brought by a motor or engine to machine through the pulleys. There are many kinds of the viscoelastic drive belt systems which have been widely used because of their importance in mechanical and vehicle engineering. Despite many advantages of viscoelastic belt drive devices, transverse nonlinear oscillations associated with the devices have limited their applications. It is found that the tension in the belt may change periodically. So, the nonlinear factors must be considered when designing and calculating the drive belt systems. At present the studies on the viscoelastic drive belt systems concentrate on the linear and nonlinear vibrations of one or two degree of freedom system. There are a few researches on nonlinear oscillations of multi-degree-freedom system in the viscoelastic drive belt systems. The nonlinear dynamic properties of multi-degree-freedom drive belt systems are investigated in this thesis. The main contents are as follows. The engineering background and the review of the researches on the viscoelastic drive belt systems is given in Chapter 1. Both the method of multiple scales and the Galerkin approach are simultaneously utilized to finish the perturbation analysis on the equations of motion for the viscoelastic drive belt system. First, the method of multiple scales is used to translate the non-autonomous governing equations of motion to the partial differential averaged equation. Then, the Galerkin method is applied to the partial differential averaged equation yielding 6-dimensional and 8-dimensional averaged equations. The amplitude-frequency response equations of the four-degree-of-freedom nonlinear system are obtained from its averaged equations. Numerical simulations are given to obtain the response-frequency curves of a four-degree-of freedom system in case of 1:2:3:4 internal resonance. The chaotic motions of three-degree-of-freedom and the four-degree-of-freedom nonlinear systems are investigated by numerical simulations. The planer and...