Nonlinear Modal and Subsequent Mode Based Analysis of Mechanical Systems With Frictional Contact Interfaces

Abstract

The linear modal analysis technique is a very well-known technique in Dynamics. The more often used Mode Superposition principal based on modal analysis is a very handy technique for any Dynamics engineer, as it reduces the computation time for frequency and time domain analysis very drastically compared to time stepping techniques. But modal analysis is limited to linear systems only. The systems with nonlinearity such as a frictional contact interface cannot be solved using this method in ANSYS Mechanical. Assuming, systems with such nonlinearity as a linear system, leads to very unreasonable and far from the real behaviour. In this thesis, an effort has been put to find the solution of nonlinear system using nonlinear modal analysis. At first the nonlinear modes are introduced, then the feasibility of modal superposition approach for nonlinear system is also checked. At last, the aim of this work to find the techniques from the literature which can give the solution of the nonlinear system having frictional contact nonlinearity in reasonable computation time.