Indexed by:Journal Papers

Date of Publication:2015-12-01

Journal:JOURNAL OF MARINE SCIENCE AND TECHNOLOGY

Included Journals:SCIE、Scopus

Volume:20

Issue:4

Page Number:591-603

ISSN No.:0948-4280

Key Words:Bend stiffener of flexible riser; Nonlinearity; Shape optimization; Surrogate model; Pareto frontier

Abstract:A bend stiffener is one of the key auxiliaries to protect the top section of the flexible riser used in deep water. An analytical model with material and geometric nonlinearity is developed to calculate the curvature of a flexible riser with bend stiffener loaded by tension and bending moment. The models with different material properties are computed. The sensitivities of the different shape parameters are analyzed and discussed for the bend stiffener of a flexible riser with 8 in. inner diameter used in 1500 m water depth. The fatigue resistance and structural weight of the bend stiffener are set as the objective functions, while the constraints are considered as the maximum curvature of the flexible riser should be less than an allowable level. A multi-objective shape optimization model of the bend stiffener is established and solved based on a surrogate model for the structural shape parameters. Additionally, the Pareto frontier of the multi-objective optimization is constructed and analyzed. Moreover, the calculation accuracy and efficiency of three different optimization algorithms are compared and discussed. The optimization method proposed in this paper provides a new theory and an effective tool to design the structure of a bend stiffener of the flexible riser in practical application.