Real-time trace of riser profile and stress with numerical inclinometers

作     者：Chung, Woo Chul Kim, MooHyun Jin, Chungkuk 

作者机构：Texas A&M Univ Dept Ocean Engn College Stn TX 77843 USA 

出 版 物：《OCEAN ENGINEERING》 (海洋工程)

年 卷 期：2021年第234卷

页      面：109292-109292页

核心收录：

学科分类：07[理学] 0707[理学-海洋科学] 0824[工学-船舶与海洋工程] 0814[工学-土木工程] 

基　　金：National Research Foundation of Korea (NRF) - Korea government (MSIT) [2017R1A5A1014883] 

主　　题：Riser profile tracing Monitoring algorithm Inclinometer Bending moment Quadratic cubic polynomial 

摘      要：In this paper, the methodology for the real-time tracing of riser profile and bending moment by multiple inclinometers along the riser is presented with the assumption that its top (by GPS;global positioning system) and bottom (anchoring) points are known. The riser is modelled as a series of slender-beam segments and at each time step, the riser nodal points are progressively traced. For riser x-y-z displacement and bending-moment tracing, quadratic and cubic interpolation functions for each line element between two neighboring bi-axial inclinometers are employed with respect to the global and generalized coordinate systems. Analytical solutions are derived for the instantaneous riser profile and bending moment at each line s mid-point. To validate the developed riser-monitoring algorithms, a FPSO (floating production storage offloading) system with SCR (steel catenary riser) or SLWR (steel lazy wave riser) was simulated for 1-yr and 50-yr collinear wind-wave-current storm conditions with 45-deg heading and the corresponding numerical sensor signals were inputted to the algorithms for reproducing the real-time riser profiles and bending stresses. Based on the comparisons between the algorithm-predicted and actual values, the developed method is validated. The methodology can be applied to any kinds and shapes of lines and cables too.