Dynamic interface analysis

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The purpose of this on-going research program is to develop methodology and simulation-based tools for investigating the behaviour of dynamic systems operating in prescribed deterministic and pseudo-random motion environments. Attention is specifically focused on two representative systems: the helicopter/ship dynamic interface and human postural stability. Three short-term objectives are planned for the period covered by this grant application. (1) A computational model of a helicopter/ship system will be refined and integrated, along with a sea state weather model and pseudo-random ship motion generation approach, into a versatile Monte Carlo simulation such that risk-based probabilistic methodology can be used to discover elusive details relating to interface load spectra. The load spectra will effectively quantify life cycle interface loading, probability of exceeding various design peak and fatigue load limits, and allow frequency-domain correlations between platform motions and interface forces. (2) Rotor blade sailing, the phenomenon of large blade deflections occurring at low rotational speeds as the result of ship motion and unsteady aerodynamics, will continue to be investigated computationally and experimentally to discover how various conditions affect blade sailing and the extent to which the phenomenon can be attenuated using actively-controlled smart materials. Both rigid-segment and continuous beam modelling approaches are used to provide accurate computationally-efficient solutions well suited for parametric studies. (3) Postural stability research will continue to develop articulated dynamic models of humans on moving bases to determine the relationship between model complexity and fidelity and use the results to establish an accurate motion-induced interruption model. Inferences from these interrelated projects will be considered and generalized if possible in the context of the prescribed motion interface problem.