Numerical study on mode curvature for damage detection of a drilling riser using transfer matrix technique. (February 2017)

• Record Type: Journal Article
• Authors: Zhou, Xingkun; Wang, Dongshi; Duan, Menglan; Gu, Jijun; Liu, Yang
• Is Part Of: Applied ocean research. Volume 63(2017:Oct.)
• Page Start: 65
• Page End: 75
• Publication Date: 2017-02
• Subjects: Drilling riser -- Transfer matrix technique -- Mode curvature -- Damage detection; Ocean engineering -- Periodicals; 620.416205
• DOI: 10.1016/j.apor.2016.12.008
• Languages: English
• ISSNs: 0141-1187

Abstract

Highlights: Mode characteristics of drilling riser are calculated based on the transfer matrix method. Structural damage of drilling riser is detected by the mode curvature technique. Comprehensive consideration of mode shape difference, mode curvature and mode curvature difference is considered to determine the damage location. Damaged degrees of single and multiple damage in both symmetric and asymmetric positions are evaluated. Abstract: In order to prevent marine pipeline accidents caused by corrosion defect, crack or loose contact, the technique of non-destructive testing or examination (NDT or NDE) becomes great important in the flied of structural health monitoring (SHM) in ocean engineering. The objective of this study is to propose a numerical method to localize and size the structure damage of a drilling riser. One theoretical development is a simple and effective algorithm used for ocean risers' mode extraction and damage detection based on the transfer matrix technique. The merits of the developed method are that damage of risers with different boundary conditions and variable cross-sections can be localized and sized. Additionally, the relationships between damage locations and modes are discussed by comparing mode shape difference, mode curvature and mode curvature difference. Numerical results show that mode curvature values of damaged elements have little influence on those of intact elements. Based on this fact, a damage index method is developed to evaluate damage severities and explore the influence of single and multiple damage severities on damage indexes. More importantly, the outcomes are verified to be accurate enough to indicate the feasibility and reliability of the numerical method by the standard FEM package.