Abstract: Some specific characteristics of the nonlinear dynamics the correlation between nonlinear dynamics and other branches of vibration engineering are discussed. The perspective of some interesting research topics in mechanical system dynamics is suggested, including torsional vibration of main drive systems, mechanism kineto-elasto dynamics, the strength of mechanical structures and the design methodology for high-speed mechanism. Those topics are not only of important practical value but also new developments of nonlinear theory and dynamics design methodology.

Key words: Dynamical design, Mechanical system, Nonlinearity dynamical model