SHORT-TERM PREDICTION AND ANALYSIS OF WAVE-INDUCED MOTION AND LOAD RESPONSES OF A WAVE-PIERCING TRIMARAN

In this paper, we used a statistical short-term analysis in order to determine the wave-induced motions and loads responses of a trimaran ship with three side hull configurations including symmetric, inboard and outboard types. The calculation of these wave-induced loads was carried out using MAESTRO-Wave, a seakeeping analysis code. A rule-based design for the hull was created based on the American Bureau of Shipping (ABS) rules followed by building a global FEM model of the ship with MAESTRO to predict the wave-induced motion and load responses. In order to validate the numerical prediction, we tested a rigid segmented model of trimaran with symmetric side hull configuration in the National Iranian Marine Laboratory (NIMALA) towing tank. The numerical results revealed that transverse torsion moments and shear forces are significant in head seas. But, transverse bending moments have higher response magnitudes in oblique seas. Also, in transverse wave loads, outboard side hulls offer slightly better performance in waves in comparison to the other forms. This study offers useful information on wave-induced motion and load responses for the purpose of balancing sea-keeping performance as well as other design considerations in developing the conceptual design of a wave-piercing trimaran.