Ocean conditions have changed over the years, with severe and extreme wave generation occurring more frequently, resulting is larger loads and motions for offshore fixed and floating structures to contend with. It is not known exactly why ocean conditions are growing more severe, but we know that any structure being considered for offshore operations has to be designed to handle larger loads then in the past. Wave slamming, either directly or through run up is an area of growing concern with the offshore industry. During these slamming events the local forces can exceed the strength of the structural plating or the internal frames resulting in structural damage. It is often difficult to predict where these slamming events will occur, therefore large areas are required to be instrumented in order to capture these slamming events during model experimentation. Commercial pressure transducers are typically 5 mm in diameter, which corresponds to full-scale areas of approximately 0.05 m2 or less depended on the scale factor. Thus to cover a large area effectively, a large number of transducers are required. Alternatively a smaller number of larger devices such as force panels with areas of 8 m2 can be used. This area corresponds to the typical area that internal framing would experience slamming loading.
This paper describes the design and development iterations of Oceanic’s model-scale force panels and their applications on modeled offshore structures such as FPSO’s, FLNG’s, and GBS’s. A major advancement in construction of these force panels has been achieved through the use of in-house 3D printing technology to produce complex components.
The paper also presents results from controlled slamming experiments to validate the force panels with respect to piezoelectric pressure sensors and a theoretical slamming model based upon potential flow. Finally, the paper describes the transition from above water installation of the panels to submersion installation and the implementation of the inverse Duhamel analysis to remove the interference due to submerged panel dynamics from the measured response.
