ABSTRACT
Due to high reliability and low cost, monopile foundations have been widely constructed for supporting offshore wind turbines. Monopile foundations are subjected to harsh environmental loading and corrosive seawater, and because of this, corrosion pits and pitting-induced cracks have become a serious threat to the structural integrity of monopile foundations. In this paper, a residual ultimate strength prediction for the monopile foundation subjected to pitting and pitting-induced cracks is performed. The Extended Finite Element Method (XFEM) is utilized to simulate the propagation of pitting-induced fatigue crack. The residual ultimate strength of the monopile foundation subjected to fatigue cracks is then achieved by progressive failure analysis. Furthermore, a parametric study to investigate the influence of pits and cracks on the residual ultimate strength of monopile foundation is conducted. Discussion on results is made and concluding remarks are then drawn for assistance in the design of monopile foundation of offshore wind turbines.
