Modes and interactions in nonlinear dynamic systems Seminar

Event details

Linear modes of vibration are a powerful concept that are used as a basis for understanding the linear dynamic behaviour of systems across a wide range of applications. These include mechanical structures, acoustics, optics, electronics, and many more... For most systems, linearity can only be assumed under certain conditions; for example, in structural dynamics, we often need to assume that displacements are small. However, to meet the drive for efficiency, mechanical structures are becoming increasing lightweight and hence are also becoming increasingly flexible; as such, these smallness assumptions can no longer be made. This requires engineers to leave the linear dynamic regime and consider the nonlinear dynamic behaviour of structures. This talk considers how many of the useful properties of linear modes no longer apply to systems operating in their nonlinear regimes. However, despite the loss of these useful properties, linear modes still provide a useful basis for understanding nonlinear behaviour. Specifically, the interactions between modes, caused by nonlinearity, is explored by considering familiar (but often overlooked) concepts such as phase and energy. The fundamental challenges that are caused by modal interactions are shown for some practical engineering problems, and the potential solutions to these challenges are explored.