Abstract
Design of concrete columns as part of offshore structures exposed to wave slamming, relies on finite element, (FE), analysis. Measured slamming forces obtained from model tests are often used as input to the analysis. This process of calculating the structural response is not straightforward, and in practical applications, it typically does not consider hydro-elastic effects, except for possibly incorporating added mass. So, how effective are these FEA calculations? Here FE analysis of a concrete shell covering a section of a monopile is carried out. The wave impact pressures used as input to the FE calculations were measured on slamming panels fixed to a circular monopile in SINTEF’s Ocean basin. The calculated utilizations are compared statistically with directly measured utilizations of elastic shells installed in the same monopile. The results show that in most cases the calculated design utilizations of the concrete shells are significantly higher than measured utilizations. Hence, the FE analysis is conservative in most cases, even though significant non-conservative simplifications were introduced in the calculation procedure.
