Abstract
High-performance vibration control systems are critical to protecting the structural integrity
of aerospace systems subjected to severe dynamic loads, such as rotorcraft, launch vehicles,
and spacecraft. Recent advances in nonlinear vibration absorbers demonstrate effective passive
broadband vibration reduction by incorporating nonlinearity into the design. Among the most
promising are bistable nonlinear vibration absorbers, also known as nonlinear energy sinks.
While bistable structures based on springs, buckled beams, and magnets have been investigated,
the potential of bistable composite structures, which offer reduced weight and greater geometric
flexibility, has yet to be explored. This thesis investigates the feasibility of using a bistable
composite plate as the mechanism for bistability in these absorbers. A high-order analytical
model is developed for characterising the force-displacement behaviour of bistable unsymmetric
cross-ply laminated composite square plates and determining their sensitivity to gravitational
effects, imperfections, and uncertainties in lamina properties. The model is validated using
finite element analysis (FEA) and experiments, which show strong agreement and reveal key
characteristics and sensitivities for future designs. The effect of support conditions on the
nonlinear dynamics of bistable unsymmetric cross-ply laminated composite square plates is also
explored. Centre-fixed and corner simply supported configurations are analysed, and the results
agree well with FEA simulations. The corner simply supported plate exhibits larger amplitude
and wider frequency cross-well dynamics, making it ideal for energy harvesting and vibration
control. Furthermore, the feasibility of using a bistable composite plate as a nonlinear vibration
absorber (NVA) is examined through detailed numerical analysis. Several dynamic regimes
are identified, including subharmonic resonance, chaos, and strongly modulated responses,
demonstrating the bistable composite plate NVA’s ability to suppress vibrations over a broadband
frequency range.