Dynamic study of port cranes subjected to stochastic wind actions

The focus of this research is to evaluate and compare the mechanical behaviour of three different big cranes (low profile container crane, ship to shore container crane and derrick crane) subjected to wind actions, which are schematized in two different ways: the first considering the constant actions over time and the second considering that changing over time. Regarding this second point, it was assumed a Kaimal, Wingaarard, Izumi and Cotè [1] model, and the actions were determined by developing a specific Mathcad program. After a preliminary analytical cranes design, the successive steps regards the solid model and the numerical analyses performed by finite element method. The numerical results show that, if the wind actions were schematized like variable in time, the maximum displacement is greater respect the one obtained with the constant actions. This gain is important and it is not constant, but changes with the cranes type and the geometrical configurations. For low profile container crane, the increment is approximatively three time while for the derrick crane with the arm at 5° position this value is only about 20%. The research is still in progress primarily in order to extend this methodology to other lifting equipment.