Impact Loads From Drop Test of a Circular Section With 42 Force Transducers

Abstract

Results from previous model test campaigns of various large-volume platforms indicate that wave impact loads on vertical platform columns can become high in extreme sea states. Moreover, column slamming is a highly non-linear and complex problem and reliable estimation of Ultimate Limit State (ULS) and Accidental Limit State (ALS) design loads is a challenge. A model test campaign dedicated to investigate column slamming has been performed on a large volume platform at Marintek. Special effort was put into designing a model and instrumentation package that could capture the complex phenomenon of slamming due to breaking or near breaking waves as accurately as possible. As part of the validation of the instrumentation for this test, drop tests were performed on a circular section with 42 force transducers. In the model test, this section was mounted on one of the platform columns for measuring wave impacts. In the present drop tests, the same section was dropped in still water in a small basin. Different impact velocities and impact angles were investigated. High-speed video recordings were also used to document the tests. This paper presents the setup used in the drop tests. The results from the drop tests are discussed and compared to theoretical solutions.