Papers

@article{costas_influence_2022,

title = {The influence of infragravity waves, wind, and basin resonance on vessel movements and related downtime at the Outer Port of Punta Langosteira, Spain},

author = {Raquel Costas and Andrés Figuero-Pérez and José Sande-González-Cela and Enrique Peña-González and Andrés Guerra},

url = {https://www.sciencedirect.com/science/article/pii/S0141118722003017},

doi = {10.1016/j.apor.2022.103370},

issn = {0141-1187},

year  = {2022},

date = {2022-12-01},

urldate = {2026-08-10},

journal = {Applied Ocean Research},

volume = {129},

pages = {103370},

abstract = {The coupling of low-frequency oscillatory modes of a harbor with horizontal motions of moored ships can amplify the latter, causing operational and safety problems. The objectives of this study were to analyze infragravity waves and their effect on moored ship motions; to validate the Wavelet Transform Analysis (WTA) method for studying port-ship resonance in the Outer Port of Punta Langosteira, Spain; and to study the climatic forcing of downtimes. The excited resonant modes of the basin (102 and 132 s) were determined using a numerical model and high-frequency water level measurements at different points of the harbor. Yaw and sway motions of three bulk carriers were analyzed in the frequency-time domain using WTA. The results showed that the oscillation periods of the studied vessel motions are directly related to the water depth to vessel draft ratio. In addition, when the wind speeds exceeds 20 km/h, the ship moves away from the fenders, which lead to a lengthening of these periods. Based on our findings, yaw may induce oscillations of the same period in sway. Additionally, operational thresholds were proposed based on outer and inner waves data that will lead to optimize ship stays, avoiding downtimes, and to advance the safety of loading and unloading operations.},

keywords = {Downtimes, Infragravity waves, Moored vessel motions, Operational thresholds, Vessel resonance, Wavelet transform analysis},

pubstate = {published},

tppubtype = {article}

}

@article{costas_integrated_2022,

title = {Integrated approach to assess resonance between basin eigenmodes and moored ship motions with wavelet transform analysis and proposal of operational thresholds},

author = {Raquel Costas and Andrés Figuero-Pérez and Enrique Peña-González and José Sande-González-Cela and Paulo Rosa-Santos},

url = {https://www.sciencedirect.com/science/article/pii/S002980182200138X},

doi = {10.1016/j.oceaneng.2022.110678},

issn = {0029-8018},

year  = {2022},

date = {2022-03-01},

urldate = {2026-08-10},

journal = {Ocean Engineering},

volume = {247},

pages = {110678},

abstract = {Waves with periods between 25 s and some minutes can amplify the motions of moored ships, which may result in terminal downtimes and compromise safety. The purpose of this work is twofold: (i) studying infragravity waves and their influence on moored ship motions, including the definition of operational thresholds and (ii) developing a novel and integrated approach to identify and assess resonance situations using wavelet transform analysis. The resonant modes of the harbor basin were identified using a numerical model validated with full-scale data. The motions of five similar LPG vessels moored at two adjacent jetties were analyzed, both in the frequency and frequency–time domains. It was concluded that surge is the most important motion at the berth that has greater operational problems. Moreover, the infragravity motion periods vary with the mooring line pretension and are proportional to the ratio of water depth to vessel draft. Three episodes of mooring line breaking were attributed to large infragravity surge oscillations. In addition, operational thresholds for basin-vessel resonance situations were defined based on the port tide gauge data. A significant wave height of 0.075 and 0.010 m for the 30–65 s period band was established for LPGs and oil tankers, respectively.},

keywords = {Infragravity waves, Moored vessel motions, Operational threshold, Vessel resonance, Wavelet transform analysis},

pubstate = {published},

tppubtype = {article}

}

@article{munoz-ibanez_acoustic_2019,

title = {Acoustic emission processes occurring during high-pressure sand compaction},

author = {Andrea Muñoz-Ibáñez and Jordi Delgado-Martín and Elisa Grande-García},

url = {https://onlinelibrary.wiley.com/doi/abs/10.1111/1365-2478.12691},

doi = {10.1111/1365-2478.12691},

issn = {1365-2478},

year  = {2019},

date = {2019-01-01},

urldate = {2026-08-04},

journal = {Geophysical Prospecting},

volume = {67},

number = {4},

pages = {761–783},

abstract = {Granular materials submitted to uniaxial compression undergo pore space reduction due to mechanisms such as particle rearrangement and grain crushing. These changes in the internal structure of the material release energy in the form of elastic waves that can be detected by sensors sensitive to acoustic emission. In this study, Acoustic emission monitoring with a wavelet-based signal processing technique is used to identify the various mechanisms occurring during high-pressure sand compaction. Particle movement, grain failure, friction between grains and the surface of the compression cell and intergranular friction are studied. Acoustic emission data recorded during these simplified tests are used to characterize each phenomenon. Wavelet transform analyses allow the identification of useful features, making possible frequency discrimination among sliding, rolling, friction and grain fragmentation processes. For instance, we observe that at low stress, grain flow is characterized by the lowest centroid and peak frequencies, while at greater stresses, intergranular friction and grain fragmentation have the higher values. In the tests performed, the stress–strain evolution and final condition of the tested sand are broadly consistent, irrespective of the condition employed: continuous, stepwise or even variable loading rate or temperature. However, Acoustic emission data manifest much more complex behaviour (including thermal, load-rate dependency and delayed fragmentation phenomena) than that suggested by stress–strain relationships. At low stress levels, grain flow (sliding/rolling) is a relevant strain-accommodation mechanism, but so is crushing due to the effect of concentrated forces at the grain contact level. At high stresses, when crushing is generalized, intergranular friction is also a relevant phenomenon due to the increase in the coordination number produced by previous fragmentation.},

keywords = {Acoustic emission, b-value, Grain crushing, Sand compaction, Wavelet transform analysis},

pubstate = {published},

tppubtype = {article}

}