Investigation of pitch motion portion in vertical response at sides of a Tension-Leg Platform

Abstract

Tendons vertically moor Tension-Leg Platforms (TLPs), thus, a deep understanding of physical tendon stresses requires the determination of the total axial deformation of the tendons, which is a combination of the heave, pitch, and surging responses. The vertical motion of the lateral sides of the TLP is coupled with surge and constitutes a portion of the pitch motion. Tendons are connected to the sides of the TLP; hence, the total displacement of the lateral sides is related to the total deformation of the tendons and the total axial stress. Therefore, investigating the total vertical response at the sides of the TLP is essential. The coupling between various degrees of freedom is not considered in the Response Amplitude Operator (RAO). Therefore, in frequency domain analysis, the estimated vertical RAO is incomplete. Also, in the time domain, only the heave motion at the center of TLP is typically studied; this problem needs to be addressed. In this paper, we investigate the portion of the pitch motion in the vertical response at the sides of the TLP in both the frequency and time domains. Numerical results demonstrate a significant effect of the pitch motion in the vertical motion of the edges of the TLP in some period ranges.

Surge Motion Passive Control of TLP with Double Horizontal Tuned Mass Dampers

“…3 Tabeshpour et al focused on the comprehensive interpretation of the responses of the structure related to wave excitation and structural characteristics. 4 Tabeshpour and Malayjerdi researched pitch motion portion in vertical response at the sides of a TLP. 4 Rosane and Batista investigated passive and active control of the heave motion of a TLP.…”

“…4 Tabeshpour and Malayjerdi researched pitch motion portion in vertical response at the sides of a TLP. 4 Rosane and Batista investigated passive and active control of the heave motion of a TLP. 5 Li and Zhou evaluated multiple active lever-type tuned mass damper for under ground motion structures.…”