Numerical study on crashworthiness of monopile-supported offshore wind turbine due to iceberg considering fluid-structure interaction

As offshore wind energy expands into cold-region waters, offshore wind turbines (OWTs) are increasingly exposed to ice-structure interaction. In this study, a three-dimensional fluid-structure interaction (FSI) model was developed in LS-DYNA to simulate the dynamic response of a typical 5 MW monopile-supported OWT subjected to ice impact. The model explicitly accounts for coupled interactions among ice, water, and structure. A systematic parametric study was conducted to explain the effects of ice speed, shape, size, and immersion ratio on the peak impact force, structural energy absorption, local indentation depth, and tower-top acceleration and displacement responses. The response metrics were normalized to conduct a sensitivity analysis. The overall results indicate that ice speed has the greatest influence on the structural response, followed by ice shape, ice size, and the immersion ratio. These findings help improve the understanding of the ice-structure impact mechanism.