Research On Influence Of Ship Load And Wave Load On Ship Propulsion Shafting

As an important component of ship powerplant, ship propulsion shafting affect the shipfunction and voyage safety. In recent years, shipbuilding is giant-scale, morehigh-performance steel products are used in the shipbuilding and additionally the increasingpower of main engine had made the propulsion shaft become more and more shorter andthick that make the ship hull relative flexible to the shaft. Presently the method ofreasonable bearing load is used in ship shafting alignment especially in the large-scale shipshafting alignment that without regard to the influence of ship load and wave load. Butactually the shaft could not be thought to be rigid supported because of the increasingflexibility. The ship will deform in the voyage that affected by the all kinds of loads. Thispaper took a92500t bulk carrier as an example to have a research on the influence of shipload and ocean wave on propulsion shafting. The main works are summarized as following:Firstly, understand the basic theory of wave load, ascertain the effect principle of shipload and wave load on propulsion shafting, establish the model of effect between shipshafting and ship load and wave load. Study ANSYS on its ship modeling and computingpower, try to use it to compute the model.Secondly, establish the FE model of92500t bulk carrier and shaft FE model by ANSYS.By means of advanced modeling method in ANSYS, establish the ship subsection model,then archive the subsection model, and assemble the subsections into the whole ship model.Base on the whole model, inflict the light load and full load according to the practical spacestructure, and inflict wave load on the base of full load. Use inertia relief as the boundarycondition to compute the deformation on the condition of light load, full load and wave load.Extract the displacement of bearing position as the input to the shaft FE model.At last, inflict the propeller gravity and bearing displacement to shaft FE model on thebasis of alignment theory, analyze the shafting deformation and stress on ship load and waveload and get the influence of ship load and wave load on propulsion shafting. Thecalculations show that different ship load and wave load has great influence on shippropulsion shafting, especially on the penultimate bearing of main engine output end thatcould be idle load. In order to avoid the failure, the influence should be considered whenconducting shafting alignment.