Research

The majority of the practical structures are assembled structures, which include friction contact interfaces and joints.

Components of all these structures interact nonlinearly through contact interfaces and these interactions significantly affect and in many cases drastically change the dynamic characteristics of structures, such as resonance frequencies, forced response levels, spectra of the forced response.

For some conditions nonlinear interactions can result in the occurrence of a multiplicity of forced response regimes existing for the same excitation conditions, in bifurcations of the forced response, loss or gaining stability of the response regimes, chaotic vibrations, etc.

In order to design effectively and to increase the quality and reliability of the large variety of high-performance machines and critical structures, and to reduce the time and cost of their development, new approaches and methodologies need to be developed

My research intended to address the above-mentioned problems and develop a comprehensive methodology for the predictive analysis of nonlinear structural dynamic problems including the effects of uncertainty in design parameter values on the structural dynamic characteristics. The following are major directions of the research.

 Theme 1. Representative modelling of contact interactions that can be efficiently used in predictive numerical analysis of dynamics of complex structures while capturing major tribological effects for different conditions of the contact interactions. This will include the representative modelling of contacts for high energy interactions: rubbing contacts and impacts with frictions.

Theme 2. Effective methods of analysis of nonlinear forced response for large-scale FE and other models and exploration of dynamic characteristics of such structures. This will include analysis of bifurcation, stability, multiplicity of response regimes, transition from periodic to chaotic vibrations, reduction methods etc.

Theme 3. Methods for optimization of the nonlinear dynamic structures with friction, impacts, variable contact area, and other nonlinearities. This would include method for analysis of sensitivity of dynamic properties to design and contact interface parameters.

Theme 4. Analysis of variability, uncertainty, statistical characteristics and robustness of forced response in static and dynamics analysis of complex structures (including effects of mistuning in blades discs of turbomachine  and gas-turbine engines)

Theme 5. Analysis of aeroelastic problems and self-excited vibrations, including limit cycle oscillations induced by interactions of a structure with gas flow (e.g. flutter induced vibrations)   modes and friction-supported vibrations (such as brake squeal in braking systems of cars and other vehicles).