RATIONAL DESIGN OF FAST BOAT HULL

We present a new method for the rational design of the hull structure of planing boats, which considers hydro-elasticity, structural dynamics and nonlinearity of geometry and material. The method combines rules calculations with analytical expression and analysis of FSI to a practical design procedure. A design example demonstrates a saving of 20% of the bottom plate thickness, relative to design by rules, while keeping the rules allowable stress. Exceeding the rules allowable stresses enables further reduction of weight. We designed and constructed a full scale research boat and held sea trials, measuring strains at high sampling rate. Our research boat has two sides of different construction: the port side is designed by rules, while the starboard side is designed by our rational design method, with 20% thinner plates and double spacing between the longitudinal stiffeners. We present a verification of our design method: A comparison of stresses between design by rules, rational design, and measurements in the sea trials shows: For the heavy side (designed by rules), rules, rational, and trials show similar stresses, so both rules and rational are applicable for design; While for the light side (rational design), the rules dramatically over assess the stresses, while rational and trials show good agreement. We therefore expect this study to advance the design practice, to obtain more efficient boats.