A COMPREHENSIVE STUDY OF DYNAMIC RESPONSES OF TLP UNDER REGULAR WAVE LOADS

Tension leg platform (TLP) is a complicated compliant offshore structure used for oil exploitation in deep water. Because of the complexity of the system and excitation force, it is important to comprehensive study of the dynamic responses and engineering interpretation of the results. In this paper the nonlinear dynamic analysis of TLP is carried out in time domain. The time history of regular wave is generated based on wave data. The hydrodynamic forces are calculated using the modified Morison equation according to Airy’s linear wave theory. The coupling of various degrees of freedom is considered. Differential equation of motion is solved using Modified Euler Method (MEM). The power spectral densities (PSDs) of displacements, velocities and accelerations are calculated from nonlinear responses. The focus of the paper is on the powerful and simple method to solve the equation numerically and also comprehensive interpretation of the responses of the structure related to excitation wave and structural characteristics. As an example a case study is investigated and numerical results are discussed.