The occurrence of the sinking ship in Indonesian water has to be put in consideration. One of the reasons is due to uncontrollable ship caused by a broken rudder stock. This condition will be dangerous when the high wave excitation can makes the ship capsize. In this paper a prediction of fatigue life of the rudder stock due to the ship roll motion at random sea wave is presented. The rudder stock is made from carbon steel (ST41) and installed on LCT Ship (L = 64 m, B = 12 m, T = 3.6 m). The prediction starts with a numerical simulation of ship roll motion in Indonesia water with sea states 5 (Hs = 3 m, Tp = 8.3 s), then the time history of the roll motion is used to calculate the time history of flexural moment of the rudder stock structural component. By knowing this flexural moment, the time history of flexural stress also can be found. This flexural stress time history can then applied to Palmgren – Miner formula to predict the life of the rudder stock, based on SN-Curve of the ST41. From this study it is found that the life of the rudder stock is 1.8 years.
Laboratory for Hydrodynamics Technology – Agency for Assessment and Application Technology, Indonesia
Center of Technology for Maritime Industrial Engineering – Agency for Assessment and Application Technology, Indonesia
In this paper, the dynamic behaviors are studied for the semi-submersible floating foundation of a tri-pod and spar wind turbine. It is a 5 MW wind turbine in 320 m deep water considering the coupled load effects of waves, wind, and sea current on floating foundation and mooring lines and ocean environment. The paper focuses on the key issues of floating foundation design, such as coupling dynamic analysis model and calculating methods. The motion performance and line tension are investigated by using an aero-hydrodynamic software Ansys-AQWA. The results show that the tri-pod wind turbine with mooring system may work in the ocean environment without heave-plates.
Department of Maritime Engineering, Amirkabir University of Technology, Tehran, Iran
The increasing of shipping activities through the Northern Sea Route (NSR) and growth of oil and gas activities in Arctic and Sub-Artic regions require suitable design of ice-going ships and planning operations in ice. In 2002, Sumitomo Heavy Industries has built advanced ice-ship called “Double Acting Tanker”. This paper discussed development of methodology to determine the Double Acting Tanker operated in ice condition such as: unfrozen and frozen channels and level ice conditions. The methodology consists of ice failure test, mathematical model of ice resistance and software development was carried our using VB language. The ice failure characteristics were determined from experiment conducted in Universiti Taknologi Malaysia.
Faculty of Mechanical Engineering, Universiti Teknologi Malaysia, Skudai, Johor, Malaysia
