Investigating the interaction of fluid and structure on the body of a semi-submerged platform under the influence of regular sea waves

With the advent of technology and the expansion of human needs, the use of water platforms such as seas, oceans, and the recognition of methods and solutions for the design and implementation of marine structures is becoming increasingly clear. The semi-submerged platform is one of a variety of submarine platform platforms, which, according to the features of the platform, is mainly used for extracting deep-sea oil and gas resources. In this research a semi- submersible platform under performance condition using ANSYS finite element software is numerical modeling and It is under regular waves. The platform's geometry is based on a platform built in 2012, and the data used in this study is about the average 20 years of Caspian waves. The degree of displacement, rotation, and force of diffusion has been obtained in degrees of freedom and are compared with each other. to apply regular waves Airy theory has been used. The result of this study show that In the loading of regular waves, the two parameters of the wave period and the wave propagation angle were the determining factor in the displacement and the platform time, as well as the dispersion force resulting from the collision of the wave with the platform. Also, the results show that at a 90 degree angle of the wave with the platform, the motion state at 2 degrees Z, Ry was close to zero and was the largest amount of time around the X axis.