Shafting Torsional Vibration In The Non-linear Element Modeling Research And Simulation Analysis

The torsional vibration of propulsion shaft is one of the failure causes of internal combustion engine power plant. In tradition, the calculation of torsional vibration is based on the linear theory, but the dynamical behavior of the propulsion shaft manifests the strong nonlinear characteristics, which make the torsional vibration of propulsion shaft is investigated using the nonlinear dynamical theory necessarily.In this paper, two kinds of nonlinear components are focused. One component is Geislinger coupling, which is used to link the two adjacent axises. The coupling plays the role that buffers and reduces the vibration, enhances the dynamical performance between two axises. The other is a torsional spring shock absorber,which is often employed to alleviate the external impact.First, using the vibration theory and geometry relationship of torsional spring, the torsional spring model is established. The existence, periodicity and stability of the solution of the order-differential equation of a dynamical system using the torsional spring model obtained are studied. The particular solution of equation without damping and the convergence speed of the solution of equation with damping are discussed, respectively.Comparing with the experimental data, the model is verified to be correct.Then, taking the Dongfeng-5 locomotive internal combustion engine as an example,the torsional vibration equations with 10 degree-of-freedoms are built up by the observational method, considering the Geislinger coupling.Finally, according to the shaft parameter of the Dongfeng-5 locomotive internal combustion engine, the stress,displacement and torque angle of the free vibration and the forced vibration are computed and analyzed. Comparing with the measured data, the simulation results indicates the modeling approach and the model obtained are correct.