This study proposes a new method for evaluating the damage of aging offshore platforms, based on dynamic tests. The proposed method involves a new damage indicator for reducing the effects of occurred damages accumulated before the first measurement. One theoretical improvement is that the requirement of using the stiffness matrix of the finite element model to replace that of the measured model can be ignored in calculating the modal strain energy of the measured model. The other development is that the proposed approach can be used for providing reasonable evaluations of damages that occurred between two adjacent dynamic tests. This improvement is crucial for evaluating aging platforms because such platforms have seldom been tested for damage detection during their previous service life. For demonstrating the applicability of the proposed method, numerical studies were conducted for a 3D offshore platform based on data generated from finite element models. The results indicated that the proposed method can be used to identify accurately the damages that occurred between the two measurements and to provide an accurate estimation of damage severity.
Liu, Fu-Shun; Lu, Hong-Chao; Wang, Wei-Ying; and Yang, Dong-Ping
"PERIODIC DAMAGE EVALUATION OF AGING OFFSHORE JACKETS BASED ON CONTINUOUS DYNAMIC TESTS,"
Journal of Marine Science and Technology: Vol. 22
, Article 10.
Available at: https://jmstt.ntou.edu.tw/journal/vol22/iss6/10