Characterization of dominant mechanisms in contact interface restoring forces

Accurate representation of different parts of a mechanical system is important in construction of mathematical models for structural dynamic analysis. There are usually elements in structures – for example joints or boundary conditions – which demand more efforts for precise modeling. This is due to development of the contact mechanisms – i.e. linear or nonlinear – in normal and tangential directions of their surfaces. In this paper a method for multiple nonlinearity detection and identification is proposed. The method is applied to characterize the state of the contact mechanisms in normal and tangential directions of a nonlinear beam subjected to a frictional contact support.

► A new approach for characterization of multiple unknown elements in nonlinear systems is developed.
► The method uses measured nonlinear FRFs and a reference linear system.
► The method is applied to numerical and experimental case studies.