Fatigue Analysis of the Structural Bottom of an Aluminum Planing Craft through Vibratory Load of the Propeller System

José Marín, Carlos Cuenca
2015 Ciencia y Tecnología de Buques  
This work analyzed the structural fatigue of a high-speed craft, which has a propeller system formed by two 493-hpengines connected through speed multipliers to water jet systems. Its aluminum alloy structure has combined-typeframing. The useful life of the boat bottom's structure was determined considering the cyclical loads generatedby the propulsion system, using the Finite Elements method and applying the effort-number method of cycles tofailure. For this, a structural model was developed
more » ... the selected zone, which was analyzed with the SAP2000program, to obtain complex amplitudes of the stress supported by the structure. Thereafter, with these results thestress range was determined and, then, using S-N curves for Aluminum the number of cycles that needed to becarried out by six structural details selected was determined, for its failure. Using Miner's Rule, combined with thecraft's assumed work modes, the time of the useful life time of the referential details selected during an hour wasdetermined. Finally, if the craft operates for three hours per day, the bottom structure of the boat analyzed wouldhave a useful life of 14.5 years, when working principally in low speed rating.
doi:10.25043/19098642.111 fatcat:fgcxvvr7zzc3loy22tqbtclqgq