Publicacións

@article{hu_optimising_2024,

title = {Optimising the dosage of bio-rejuvenators in asphalt recycling: A rejuvenation index based approach},

author = {Yongping Hu and Jack Ryan and Anand Sreeram and Max Allanson and Ana M. Rodríguez-Pasandín and Lu Zhou and Bhupendra Singh and Haopeng Wang and Gordon D. Airey},

url = {https://www.sciencedirect.com/science/article/pii/S0950061824019032},

doi = {10.1016/j.conbuildmat.2024.136761},

issn = {0950-0618},

year  = {2024},

date = {2024-06-01},

urldate = {2026-04-20},

journal = {Construction and Building Materials},

volume = {433},

pages = {136761},

abstract = {While significant research efforts have been devoted to the rejuvenation of aged bitumen using bio-rejuvenators, a universally recognised approach for dosage optimisation is still yet to be established. Aiming to develop standardised methods to determine the optimal dosages of six types of bio-rejuvenators, this study validated the use of a rheology-based rejuvenation index as a potential universal method. Rheological properties of rejuvenated binders, determined through frequency sweep tests, multiple stress creep and recovery tests, linear amplitude sweep tests, and bending beam rheometer (BBR) tests were carried out with the properties of virgin binder as reference targets. The results indicated that the applied rheology-based rejuvenation index is a feasible approach. This index can ensure improved low- and intermediate-temperature (fatigue) performance of aged bitumen while maintaining high-temperature performance within acceptable limits. Further characterisation of the binders by Fourier Transform Infrared Spectroscopy (FTIR) analysis suggested that the bio-rejuvenation processes will commonly only involve physical softening rather than a chemical reversal of ageing. Therefore, the use of chemistry-based indices is likely not feasible.},

keywords = {Bitumen, Dosage, Fatigue, FTIR, Rejuvenation, Rheology},

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}

}

@article{munoz_fatigue_2020,

title = {Fatigue Study of the Pre-Corroded 6082-T6 Aluminum Alloy in Saline Atmosphere},

author = {Alejandro Fernández Muñoz and José Luis Mier Buenhombre and Ana Isabel García-Diez and Carolina Camba Fabal and Juan José Galán-Díaz},

url = {https://www.mdpi.com/2075-4701/10/9/1260},

doi = {10.3390/met10091260},

issn = {2075-4701},

year  = {2020},

date = {2020-09-01},

urldate = {2026-08-06},

journal = {Metals},

volume = {10},

number = {9},

pages = {1260},

publisher = {Multidisciplinary Digital Publishing Institute},

abstract = {This work studies the influence of the saline atmospheric corrosion on the fatigue strength of 6061-T6 aluminum alloy. For this purpose, this alloy was subjected to tests in a salt spray corrosion chamber at different exposure times (1, 2, and 3 months) according to ASTM B117 standard. The morphological study of the pits was carried out by confocal microscopy. Subsequently, fatigue tests were performed at variable stresses whose maximum stress (Smax) was between 30% and 95% of the yield strength (S0) in order to keep them within the zone of elastic behavior of the material. Data were analyzed using the Basquin equation and the maximum likelihood function method. The results show a similar decrease in the conventional fatigue limit (2 × 106 cycles) after one month (98 MPa) and two months (91 MPa) of corrosion. After three months of corrosion, the material showed a very important reduction in the fatigue limit (68 MPa) with respect to the uncorroded material (131 MPa). The data of Se/S0 (fatigue limit/yield strength) versus the ratio Pm/Dm (pit average depth/pit diameter at zero depth) can be fitted to a logarithmic curve.},

keywords = {6061-T6 aluminum alloy, Basquin’s equation, confocal microscopy, Fatigue, maximum likelihood method, pitting},

pubstate = {published},

tppubtype = {article}

}

@article{ouro_analysis_2019,

title = {Analysis of array spacing on tidal stream turbine farm performance using Large-Eddy Simulation},

author = {Pablo Ouro and Luis Ramírez-Palacios and Magnus Harrold},

url = {https://www.sciencedirect.com/science/article/pii/S0889974619301161},

doi = {10.1016/j.jfluidstructs.2019.102732},

issn = {0889-9746},

year  = {2019},

date = {2019-11-01},

urldate = {2026-08-06},

journal = {Journal of Fluids and Structures},

volume = {91},

pages = {102732},

abstract = {Design of efficient tidal arrays relies on the adopted spacing between turbines and their mutual interplay. Turbines affected by wake shadowing operate in harsher flow conditions, such as higher turbulence levels or lower incident velocity, which leads to reduced performance and larger extreme and fatigue loading. To extend the knowledge about turbine-to-turbine interplay in tidal arrays, high-fidelity numerical simulations using a Large-Eddy Simulation-Actuator Line Method (LES-ALM) are carried out to quantify the impact of row spacing. The developed Digital Offshore FArm Simulator (DOFAS) validates well with experimental data in terms of flow statistics and hydrodynamic coefficients, which demonstrate its adequacy to resolve the complex fluid-turbines interaction. In the cases with spacing of four and eight diameters between the rows, the lack of wake recovery has a detrimental effect on back-row turbines whose efficiency dramatically drops compared to those in the front-row. The LES-ALM captured the low-frequency wake meandering phenomenon responsible for uneven periodic loading on back-row turbines. The devices placed in the front-row suffer the largest thrust loads, blade-root bending moments and support structure moments, whilst the outermost back-row turbines experience the largest tower yaw moments due to their simultaneous exposure to low-momentum turbulent wakes and high-velocity free-stream flow. Finally, damage equivalent loads estimated by the LES-ALM are maximum for the front-row turbines except the tower yaw moment which is maximum on the outermost back-row turbines.},

keywords = {ALM, Arrays, Fatigue, Horizontal axis tidal turbines, LES, Tidal energy, Wake recovery, Wake-device interaction},

pubstate = {published},

tppubtype = {article}

}