امین محمودی

One of the greatest discoveries of 20th century was oil and it has so many applications that it cannot be separated from mankind. The oil exploration has started as early as 1900 and the oil exploration initially was concentrated on land. As the need for oil expands in an explosive rate, need for find new discoveries was eminent. During the middle of 20th century, oil discovery started in near shore and medium range of water depth. The need for qualified offshore structural design are rapidly increasing as the oil industry moves into deeper water in the search for additional supplies of oil and gas, new technology is emerging at a rapid peace for the development of new concepts for offshore platforms. In this thesis, accelerated assessment of a semi-submersible platform that has been tested experimentally in a towing tank was simulated with ANSYS AQWA. Platform Movement with six degrees of freedom in regular waves is examined in both frequency and time domains. Thus the frequency domain outcome are damping and added mass coefficients, wave forces (at different angles of incidence) and Response amplitude operators plots. After simulation in frequency domain, the semi-submersible platform's vertical acceleration calculated by using response amplitude operators. The process for 9 cases (9 waves with different period and amplitude) repeated and the results are taken. After comparison of the results with the experimental results can be seen, the simulation performed on the semi-submersible platform has a very low error and acceptable difference. Therefore the other parameters that are not recoverable in the lab, could be withdrawn in the simulation. Then causes of motion sickness at sea (seasickness) will be explained. Eventually, after calculating the values of vertical acceleration (acceleration due to heaving) and by using the existing standard in the field of human reaction to vertical movements and oscillations, the crew's comfort and performance on the semi-submers