Digital twin framework for safety operation and maintenance of marine dynamic flexible cables

Abstract

Addressing the requirements for intelligent development of marine energy equipment, a DT framework for safety O&M of marine dynamic cables are firstly proposed in this paper. Through a meticulous analysis of the mechanical behavior of flexible cables in service, the dynamic cable is simplified into a beam model with tension-bending loads, and the cross section structures can be reduced to helical beam models. The governing stress equations are utilized to establish the relationship between stress distribution in critical cable layers and the local cable configuration. In additional, an integrated safety O&M database are established, and critical results are intuitively presented in a 3D dynamic cable model. Compared with conventional Date-driven DT methods, the proposed models only utilizes three inclinations for cross-section stress distribution reconstruction. Furthermore, this DT model effectively combines the monitoring data with the physical cable characteristics, which has an improved applicability to all serving conditions. In order to verify the accuracy of the proposed framework, a DT model with experiment and numerical simulations are meticulously executed. Comparative analysis between the numerical simulation model and monitoring results is conducted, the maximum AEs of axial stress and contact stress under survival sea state are only 7.93 MPa and 11.93 MPa. The reconstruction for a set of conditions took only 0.37s. The results demonstrate that the present DT model can captures variations in cross-sectional stress and provides valuable technical support for the safety O&M of marine cables.