Research on structural damage detection of offshore platforms based on grouping modal strain energy

• Published in: Ocean engineering 2017-08, Vol.140, p.43-49
• Main Authors: Liu, Guijie, Zhai, Yuanzhuang, Leng, Dingxin, Tian, Xiaojie, Mu, Weilei
• Format: Article
• Language: English
• Subjects: Modal analysis; Modal strain energy; Offshore platform; Structural damage
• ISSN: 0029-8018; 1873-5258
• DOI: 10.1016/j.oceaneng.2017.05.021

Nowadays, natural load excitation cannot detect all modal problems when testing vibration responses of offshore platforms. To overcome this issue, the present paper proposes a novel method to detect structural damages of offshore platforms based on grouping modal strain energy. This method divides the unit modal strain energy into axial tension-compression and bending. It may not only expand known modals and overcome the incomplete modal parameters under natural load excitation, but also could estimate the damage locations based on low-order modal parameters. The proposed method was verified by numerical simulations. Based on simulations on different damage conditions of a jacket offshore platform, damage locations could be determined accurately through comprehensive analysis of grouping modal strain energy distribution. •Several modal damage indexes are compared and analyzed.•An structural damage diagnosis method based on grouping modal strain energy indexes is proposed.•The proposed method was verified by combining ANSYS and MATLAB.•Damage locations could be determined accurately through grouping modal strain energy distribution.