Frequency analysis and design of nonlinear systems: theories, methods and their applications

The PhD project offered by Professor Z Q Lang is concerned with the development of the theories and methods for the frequency analysis and design of nonlinear systems and the application of these theories and methods in a wide range of science and engineering areas.

Linear system frequency domain analysis and design theories and methods are the basis of the technologies in telecommunication, control, signal processing, mechanical and civil structural vibration suppression and health monitoring, etc a wide range of areas. Given the inherent nonlinear behaviours of practical science and engineering systems, and some beneficial effects that nonlinearity can bring to engineering designs that have recently be revealed by our studies at Sheffield, the extension of well-established linear system frequency domain theories and methods to the nonlinear case has considerable scientific and engineering significance. Motivated by these, a series novel concepts, theories, and methods have been proposed and developed at Sheffield, and many of these new results have been successfully applied in solving real scientific and engineering problems including the analysis of biological signals, the analysis and design of civil and mechanical vibration isolation systems, non-destructive evaluation and health monitoring of engineering structures, and engineering system fault diagnosis, etc.

Depending on the interests of the candidates, the PhD project can focus on the further development of the nonlinear system frequency domain analysis and design theories and methods, or be concerned with the application of the novel techniques that have been proposed at Sheffield to tackle different science and engineering problems. We have established a range of national and international collaborations to facilitate the application studies including, for example, building vibration isolation during earth quakes and signal analysis for eddy current based structural health monitoring etc. Many of the studies are supported by funding from UK EPSRC and Royal Society, which provides a very good research environment including laboratory facilities for the PhD projects.