STUDY ON THE CALCULATION OF MOORING LINE WITH CLUMP WEIGHTS FOR A FLOATING STRUCTURE USING NONLINEAR ANALYSIS IN SAP2000

Phạm Quốc Hoàn; Đoàn Đắc Thành

doi:10.34238/tnu-jst.12634

STUDY ON THE CALCULATION OF MOORING LINE WITH CLUMP WEIGHTS FOR A FLOATING STRUCTURE USING NONLINEAR ANALYSIS IN SAP2000

About this article

Received: 20/04/25 Revised: 15/07/25 Published: 15/07/25

Authors

1. Pham Quoc Hoan , Vietnam Maritime University
2. Doan Dac Thanh, Vietnam Maritime University

Abstract

This article proposes a new model for calculating a single mooring line with clump weights using the finite element method implemented in Sap2000 software. By analyzing the behavior of the mooring line, the authors introduce a model that utilizes the Cable element - designed to resist only axial forces - in combination with the Nonlinear solver and the P-Delta Plus option. This configuration allows for accurate modeling of large displacements and deformations by continuously updating the stiffness matrix during the analysis. The proposed model effectively simulates the behavior of flexible mooring lines under significant loading conditions, accounting for large displacements and nonlinear geometric effects. It enables the determination of key response parameters such as mooring line deformation, inclination angle, axial tension, lateral displacement of the floating body, and forces acting on the anchor pulley. To verify the model’s accuracy, its results were compared against those from an analytical solution presented in a previously published study. The discrepancy between the two sets of results was found to be minimal, confirming the model’s reliability. With the advantage of being implemented in Sap2000 - a widely used structural analysis software in Vietnam - the model is intuitive, easy to construct, and yields reliable results. It shows strong potential for widespread application, not only in the analysis of single mooring lines with clump weights but also in similar problems involving flexible cable systems.

Keywords

Mooring line; Floating structure; Finite element method; Sap2000; Nonlinear analysis

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DOI: https://doi.org/10.34238/tnu-jst.12634

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