As contemporary ship-to-shore cranes are continually growing larger, wind loads are becoming more important, especially during storm conditions. Current design standards using conservative wind calculations put constraints on the crane design, prompting new methods for calculating wind loads.
In this research, a model was built based on a representative Belgian crane, using a ’Finite Element Method’-software (FEM), with the aim of using it to compare the design standards to the actual behaviour of the crane. Self-weight and permanent loads, hoist loads and wind loads were incorporated into the model, which simulates both the in- and out-of-service status of the crane. Normal forces in the crane legs were measured using strain gauges on each leg and wind loads were determined by four wind meters installed at different heights. Measured strains in the crane legs were compared with strains as predicted by the model in several cases with varying wind speed, wind direction, boom position and trolley position.
The model predicts strains in the same order of magnitude as the measured data and the crane leg forces clearly correlate with positions of the trolley and boom. However, there remains a significant deviation between predicted and measured data, which may be related to inaccuracies of the strain gauges, and the lack of strong winds during the measuring period. Improved calibration methods, inclusion of thermal loads into the model, more complex modelling of wind loads, and extended measurement periods to capture the effects of stronger winds are likely to refine the applicability of the model.