Loading and Response of Offshore Wind Turbine Support Structures: Prediction with Comparison to Measured Data

The effectiveness of numerical prediction of structural dynamic response is assessed for a wind mast support structure typical of wind turbines, but without the turbine itself. This effectiveness is assessed by comparison of predicted mechanical strain below the waterline of the structure with measured field data. Particular attention is paid to the effects of wave directional spreading. In the model, wave loads are generated from a series of simulated irregular time-histories associated a single significant wave height and period, but two distinct spreading parameters. Load predictions are based the Morrison equation and the structural response is computed by solving a finite element model of the structure in the time domain. Comparisons are based on the variances of the response process.