Dynamic Characteristics Of Marine Derrick Under Wave Loads

Human’s exploration and exploitation of marine resources is never giving up. Especially with the increasing depletion of onshore oil resources, for marine mineral deposits is showing booming trend. Jacket platform as the main structure of the shallow sea oil drilling plays a very important role, and at the working condition, the marine derrick on the platform is not only to bear the work load and wind load but also need to consider the wave load on it. In this paper, as a precondition to the wave load for the main contents of the jacket platform and derrick overall dynamic characteristics analysis, Details are as follows:1. During the relevant simplified premise, Using ANSYS software to build finite element models for shallow water jacket platform and derrick, respectively doing design conditions static analysis for marine derrick and platform-derrick. The results can make a contribution to confirm the correctness of the overall modeling method.2. Using ANSYS software’s modal analysis module to calculate model natural frequency based on the analysis results, through the harmonic analysis to validate the rationality of the establishing model; Through the study of the wave theory and combining Morison formula to calculate the wave force when the model under the storm self storage and the eutopic working two design condition, and using the calculated results combine with transient analysis function to analysis the whole model’s dynamic characteristics under the design wave condition.3. Taking into account the Stokes 5 randomness of waves, selecting P-M wave spectrum as an incentive spectrum to the platform-derrick model in order to using the PSD spectrum analysis to calculate the dynamic characteristics under the random waves, hoping to provide a reference for subsequent wave dynamics of the platform-derrick structural.