Damage Detection in Offshore Platform Structures under Environmental Loads Using Modal Strain Energy Method

摘要

A damage detection and severity estimation method for jacket offshore platform under environmental loads using modal strain energy method is presented in this paper. This method is different from former localization ones which need complete modal parameters after the damage occurring. It is remarkable because of its ability to diagnose platform health conditions within only a few amounts of identified natural frequencies and limited modal shapes from the damaged structure. First of all, a study of environmental conditions and environmental loads is introduced to expound how the wind, wave and current effect on the structure. After the theoretical derivation of modal strain energy method and the algorithm analysis, a Bohai Bay offshore platform model is demonstrated in the numerical examples, and the final results indicate that an excellent updating is achievable by applying the new method.