Papers

@article{fernandez_rodriguez_structural_2025,

title = {Structural Optimization and Comparison Study of Different Configurations of Offshore Wind Turbine Jacket Substructures},

author = {Noelia Fernández-Rodríguez and Iván Couceiro-Aguiar and Xesús Nogueira-Garea and Ignasi Colominas-Ezponda},

url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/we.70014},

doi = {10.1002/we.70014},

issn = {1099-1824},

year  = {2025},

date = {2025-01-01},

urldate = {2025-01-01},

journal = {Wind Energy},

volume = {28},

number = {5},

pages = {e70014},

abstract = {In this work, the design of a three-legged jacket is presented, taking into account the susceptibility to the directionality of the loads in comparison with a four-legged jacket. For this purpose, two jackets with different orientations with respect to the incoming environmental loads were modelled: the G30, which has two legs facing the main incoming environmental actions, and the G90 jacket, which only has one. In addition, mathematical optimization is proposed to minimize the weight of the structure using a combination of size and shape optimization techniques. The solution to the proposed optimization problem is based on the application of sequential linear programming, which is then solved using the simplex method. In this study, a first-order sensitivity analysis was reformulated to extend its applicability to a three-legged configuration. This sensitivity analysis provides the derivatives of the coordinates of the structure nodes with respect to the design variables required for the shape optimization. The proposed formulation allows optimized designs with a weight reduction of around 40% relative to the UpWind jacket. In the G30 jacket, there was an increase in fatigue damage from the cyclic loads. The G90 jacket and optimal four-legged jacket present design limitations conditioned by the effects of compression stresses and buckling. The differences between the G30 and G90 models highlight the sensitivity of the structural response to the directionality of the loads, which can constitute a limiting factor in the cost reduction of three-legged jackets. An interesting result of this research is that the added shape design variables for the jacket footprint allowed a significant improvement of the optimized designs.},

note = {_eprint: https://onlinelibrary.wiley.com/doi/pdf/10.1002/we.70014},

keywords = {jacket structures, offshore structure design, offshore wind energy, structural optimization},

pubstate = {published},

tppubtype = {article}

}

@article{couceiro_computer_2021,

title = {Computer software for analysis and design optimization of power transmission structures by simulated annealing and sensitivity analysis},

author = {Iván Couceiro-Aguiar and José París-López and S. Martínez and Fermín Navarrina-Martínez and Ignasi Colominas-Ezponda},

url = {https://doi.org/10.1007/s00366-020-01022-x},

doi = {10.1007/s00366-020-01022-x},

issn = {1435-5663},

year  = {2021},

date = {2021-10-01},

urldate = {2026-08-06},

journal = {Engineering with Computers},

volume = {37},

number = {4},

pages = {3649–3663},

abstract = {This paper presents a computer software for the optimization of power transmission structures. The software employs a modified version of the Simulated Annealing algorithm that has been proven effective in large engineering problems. The target structures are three-dimensional steel trusses to be used as supporting towers of electrical lines. A mixed formulation merging continuous and discrete design variables is proposed for optimizing the size and shape of the trusses, including a first-order sensitivity analysis that reduces the computational cost. The implementation can be adapted to any kind of transmission tower and allows to quickly create a model to be analyzed and optimized in a few sequential steps. Despite its simplicity of use, the tools provided by the proposed framework allow to perform a full analysis of the design and provide an entire comprehension of its structural behavior. The software also includes a post-process and visualization tool set in a user-friendly graphical interface.},

keywords = {Optimization software, structural optimization, Transmission towers},

pubstate = {published},

tppubtype = {article}

}

@article{couceiro_optimization_2020,

title = {Optimization of Offshore Steel Jackets: Review and Proposal of a New Formulation for Time-Dependent Constraints},

author = {Iván Couceiro-Aguiar and José París-López and Fermín Navarrina-Martínez and Raquel Guizán and Ignasi Colominas-Ezponda},

url = {https://doi.org/10.1007/s11831-019-09342-y},

doi = {10.1007/s11831-019-09342-y},

issn = {1886-1784},

year  = {2020},

date = {2020-09-01},

urldate = {2026-08-06},

journal = {Archives of Computational Methods in Engineering},

volume = {27},

number = {4},

pages = {1049–1069},

abstract = {In this work, a methodology for the optimization of offshore wind turbine substructures (jacket type) is presented. The use of a coupled model allows for capturing the full dynamic interaction between all the elements. The structural analysis is carried out in the time-domain. A non-linear integration scheme is necessarily applied due to the effects of the rotation of the blades. Environmental actions, such as wind and waves, are considered as loading conditions. Fatigue damage at the welds of the joints is taken into account. The objective function to be minimized is the weight of the structure. The shape and sizing optimization model is stated in terms of two variables that define the overall shape of the jacket, along with the dimensions of the cross-sections of the structural members. The model is subjected to Ultimate Limit Stress (ULS), Fatigue Limit State and natural frequency constraints. The time-dependent ULS constraints are efficiently treated by means of a new formulation that is based on constraint aggregation. Fatigue accumulation during the whole design life of the structure is accurately assessed, without the need for excessively costly numerical simulations. The optimization problem is solved by means of Sequential Linear Programming, what requires a full first order sensitivity analysis to be performed. The efficiency, reliability and robustness of the proposed methodology is demonstrated by optimizing a real jacket design.},

keywords = {Fatigue, Offshore jackets, Structural dynamics, structural optimization},

pubstate = {published},

tppubtype = {article}

}