Abstract:To gain accurate calculation about standing stability of wind turbine installation vessel, two different constraint models of pipe legs, the conventional hinge model and the pile and soil interaction model, were established. With the two models, numerical analysis was conducted to investigate the standing stability of wind turbine installation vessel based on static, modal and transient dynamics analyses.The comparison results of two models show that the static analysis of the pile and soil interaction model is greatly different with that of the hinge model, while the two model maximum stresses are far below the yield strength of pile leg.The two natural frequencies of pile leg vary slightly, and the maximum bending moment occurs at the end of pile legs without occurrence near the water surface. The maximum displacement of legs under variable load is greater than that under static load. The pile leg of wind turbine installation vessel has good stability, and higher accuracy can be achieved by the pile and soil interaction mode to analyze stability.