Jarrad Wallace

Abstract

Traditional rig design methodologies are often based on empirical “rules-of-

thumb” that frequently result in a rig that is over built and excessively

heavy, which is due primarily to the coarse approximations made in calculating

member loads and subsequent large factors of safety required to avoid

mechanical failure.  This paper investigates the feasibility of using

mathematical models in improving the rig design process, and applying

optimisation techniques to minimise the weight of the structure.  It presents a

new method of quickly and efficiently evaluating rig loads and deflections

under multiple loading conditions, incorporating complementarity constraints to

handle tension-only members.  This is then extended to investigate the non-

linear optimisation of member properties and rig geometry in attempting to

achieve minimum rig weight, as a direct method of improving yacht performance.