ON THE COMPUTATION OF THE SLOW DYNAMICS OF NONLINEAR MODES OF MECHANICAL SYSTEMS

摘要: Abstract A novel method for the numerical prediction of slowly varying dynamics nonlinear mechanical systems has been developed. The is restricted to regime an isolated mode and consists a two-step procedure: In first step, multiharmonic analysis autonomous system performed directly compute amplitude-dependent characteristics considered mode. second these modal properties are used construct two-dimensional reduced order model (ROM) that facilitates efficient computation steady-state unsteady provided interactions absent. proposed methodology applied several ranging form single degree-of-freedom Finite Element models. Unsteady vibration phenomena such as approaching behavior towards equilibrium point or limit cycles, resonance passages studied regarding effect various nonlinearities cubic springs, unilateral contact friction. It found ROM very fast accurate slow systems. Moreover, concept offers huge parameter space including additional linear damping, stiffness near-resonant forcing.