Dynamic Motion Characteristics of Floating Structures with Tuned Liquid Multiple-Column Dampers

Abstract

The pitch motion of offshore floating structures induced by wave loading is a critical design issue affecting operational safety and performance. The focus of this investigation was a tuned liquid multiple-column damper (TLMCD), which employed multiple interconnected liquid columns to enhance vibration mitigation within a fixed structural footprint. The coupled equations of motion for a floating structure integrated with a TLMCD were derived, and a two-dimensional numerical model based on potential flow theory, the boundary element method, and linear wave theory was developed and validated through wave flume experiments. Parametric studies were conducted to examine the effects of key design parameters, including the liquid column water level and structural draft, on surge, heave, pitch, and liquid dynamic responses. The results indicated that, under a two-column TLMCD configuration, the pitch motion was reduced by approximately 75% compared with the no-damper case, and a further reduction was achieved by increasing the number of vertical liquid columns. The liquid column water level was identified as the dominant parameter governing pitch mitigation, whereas the structural draft primarily influenced the heave response. Overall, the results demonstrated that TLMCDs provide effective and practical motion-control capability for floating structures with limited installation space.