Nonlinear Modal Reduction to Investigate the Dynamics of Disordered Systems

The study of the dynamic behaviour of disordered structures often implies the analysis of the sensitivity of the structural response to the random parameters which characterize its stiffness and damping. This consideration actually involves the solution of many more differential equations than the “ordered” structure (i.e., the structure not affected by randomness of material or geometry). In order to reduce the computational effort, a methodology is proposed, which makes use of the nonlinear normal modes to investigate both the dynamic behaviour of the structure, and its sensitivity to random parameters.