Documents published in Scipedia

• Report on recommendations for predictive maintenance of FRP-based OWTP platforms (T4.4)

  C. García, M. Moutinho

  Fibregy OA (2024). Vol. Public Deliverables, 23

  
  

  Abstract

  This report will gather recommendations and procedures to be considered in the analysis of predictive maintenance in OWT platforms built in FRP materials, considering the different SHM strategies, instrumentation and a digital twin models developed in the context of FIBREGY. It should be noted that the diagnosis of the marine offshore structures will be based on the variations of various key performance indicators (KPIs), which will provide real-time information about the damage state and structural condition of the offshore platforms, including KPIs related to the onboard equipment and systems if needed. Special attention will be also paid to the optimum number and location of the sensors to be embedded in the offshore platforms.

  Abstract
  This report will gather recommendations and procedures to be considered in the analysis of predictive maintenance in OWT platforms built in FRP materials, considering the [...]

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• Project guidelines and recommendations for using FRP in large OWTPs

  J. Petiteau, S. Paboeuf

  Fibregy OA (2024). Vol. Public Deliverables, 22

  
  

  Abstract

  The project guidelines will define the methodology for the design assessment, the performance criteria to be applied and recommendations for the construction of OWTP in FRP. The report will also identify possible gaps and deviation for the certification

  Abstract
  The project guidelines will define the methodology for the design assessment, the performance criteria to be applied and recommendations for the construction of OWTP in FRP. The [...]

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• Critical review of applicable standards and gaps identification in FRP offshore structures (T4.3.1)

  E. Sanchez, C. García, A. Jurado, J. Petiteau, S. Paboeuf, R. Zaringue, P. Ropero

  Fibregy OA (2024). Vol. Public Deliverables, 21

  
  

  Abstract

  The conclusions of an extensive review of the regulations and standards related to the use of conventional (steel and concrete) and unconventional materials (FRP materials and others) on marine structures will be included in this report, as well as the gaps that need to be filled in in the future by regulatory bodies to enable the rolling out of OWTP platforms in FRP materials. A two-tier strategy will be performed with the fundamental objective to carry out the critical review. Firstly, it will be carried out an analysis of the potential standards for the application of FRP materials in the design of offshore structures. Secondly, it will be identified the existing gaps for the application of FRP materials in the design of the W2Power and the TIDETEC’s turntable tidal turbine developed in FIBREGY. The findings of this report will be used as the background of the deliverable 4.7 focused on the development of project design guidelines and recommendations for using FRP in large OWTPs.

  Abstract
  The conclusions of an extensive review of the regulations and standards related to the use of conventional (steel and concrete) and unconventional materials (FRP materials [...]

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• Multifunctional materials for SHM diagnosis and structural performance assessment

  C. García, B. Fernandes, R. Mendes, F. Otero

  Fibregy OA (2024). Vol. Public Deliverables, 20

  
  

  Abstract

  This report will evaluate the structural health monitoring (SHM) methodology developed in the framework of FIBREGY to obtain the damage state of the fibre-based structural elements used in offshore platforms. The non-destructive vibration-based methodology deals with the variations of the key performance indicators (KPIs, e.g. overall vibration energy, damping, etc.) which are influenced by the presence of damage in the FRP materials. To assess the damage state of the multifunctional materials, a set of sensors and/or optical fibers will be interleaved in the interlaminar regions of the FRP-based materials used in the marine structures. Initially, the main scope of this report is to explore the selection of the most suitable sensors to manufacture the multifunctional materials. Subsequently, the mechanical performance of the multifunctional materials will be analyzed with the paramount purpose to evaluate the possible weakness of the material induced by the embedding of the sensor. Last, it will be considered the testing of different specimens of multifunctional materials and the preparation of the best strategy for the validation of the monitoring system in a real-case through one of the WP6 demonstrators (FRP-based towers).

  Abstract
  This report will evaluate the structural health monitoring (SHM) methodology developed in the framework of FIBREGY to obtain the damage state of the fibre-based structural [...]

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• Connections in offshore structures

  B. Fernandes, J. Nuno-Silva, J. Cardoso, M. Moutinho, F. Otero, P. Ropero, O. Chan Taw, R. Mendes

  Fibregy OA (2024). Vol. Public Deliverables, 19

  
  

  Abstract

  Report containing a benchmark of the connection technologies in OWTP structures, their respective evaluation and selection. The report will also include the re-design and optimization of the most promising connections, supported by a detailed description of the experimental testing campaign.

  Abstract
  Report containing a benchmark of the connection technologies in OWTP structures, their respective evaluation and selection. The report will also include the re-design and optimization [...]

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• Environmental protection of composites

  O. Chan Taw, A. Comer, N. Goutay, F. Otero

  Fibregy OA (2024). Vol. Public Deliverables, 18

  
  

  Abstract

  The report of deliverable D2.3 includes all the results of the durability tests performed during the extensive experimental campaign. The most relevant laboratory tests to evaluate the environmental performance of the various solutions are listed below: - Alternate and continuous immersion in salt solution (ISO 11130, ISO 2812) - High Humidity Test (ISO 6270) - 500 hours at 40 °C and 98 % HR - QUV accelerated weathering test (ISO 11507) - 1000 hours with cycles of 4 hours UV light / 4 hours of high humidity - Climatic chamber with thermal cycles (-20°C / + 80°C) - Adhesion tests: Cross Cut (ISO 2409) and Pull Off (ISO 4624) before and after each ageing test - Gloss (ISO 2813) and Colorimetry (ISO 7724) measurements before and after each ageing test - Observation of visual defects before and after each ageing test - The effect on the texture on biofouling will be evaluated at coupon level in natural sea water basin A dedicated Design of Experiments (DOE) will be built to optimize the number of samples to be tested. The durability will be evaluated for the following configurations: - At least 2 paint references (from 2 suppliers or 2 different chemistries) - At least 2 composite substrates (1 thermoset and 1 thermoplastic) - Three types of application: adhesive paint film, in-mold application of paint film and stand ard liquid paint application - Three surfaces textures: flat surface and two fouling release textures - Unprotected composite samples as a comparison

  Abstract
  The report of deliverable D2.3 includes all the results of the durability tests performed during the extensive experimental campaign. The most relevant laboratory tests to [...]

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• Fatigue performance of composites

  A. Comer, A. Hejjaji, G. Bhatia, J. R. Pothnis, J. Cardoso

  Fibregy OA (2024). Vol. Public Deliverables, 17

  
  

  Abstract

  The deliverable will present the results and conclusions of the different fatigue tests to be performed. An interim report will be delivered by month M24 describing the regular fatigue tests (O° and 90° lay-ups) and results. This data is the only one required by the numerical models for material calibration. The report will be completed by M29, including the advanced fatigue characterization performed on oblique (45°) lay-ups and also the connections.

  Abstract
  The deliverable will present the results and conclusions of the different fatigue tests to be performed. An interim report will be delivered by month M24 describing the regular [...]

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• Ongoing development of applications of the Cone Penetration Test in interpretation and design

  B. Lehane*

  ISC2024.

  
  

  Abstract

  This paper presents recent research on the application of the cone penetration test to site characterisation and foundation design. Aspects considered related to characterisation include the interpretation of relative density in granular soils, the derivation of the penetration-velocity characteristic, corrections for shallow penetration and scale effects in laboratory experiments and the influence of particle size on penetration resistance. In relation to foundation design, the paper outlines the nature of CPT-based correlations and describes the development of three types of such correlations for footings, axially loaded piles and laterally loaded piles.

  Abstract
  This paper presents recent research on the application of the cone penetration test to site characterisation and foundation design. Aspects considered related to characterisation [...]

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• The influence of soil structure on CPTu and SDMT results

  S. Oberhollenzer*, E. Lande, S. Ritter

  ISC2024.

  
  

  Abstract

  The natural structure of clays has a significant influence on its mechanical behaviour and can be characterized using insitu and laboratory tests. It was reported by Robertson (2016) that soil structure leads to an increased tip resistance (qc) and shear wave velocity (Vs) when performing seismic cone penetration tests. However, only limited studies investigated changes in soil structure by means of in-situ tests. Sensitive, marine clays were investigated within the research project "VIBE – Sustainable Ground Improvement Solution for Oslo" at the Norwegian Geo-Test site Onsøy (Gundersen et al. 2019). Possibilities and limitations of the vibro replacement method were studied for very soft ground conditions based on a full-scale field test. The influence of soil structure on in-situ measurements of piezocone penetration tests (CPTu) and seismic flat dilatometer tests (SDMT) are further studied by intentionally disturbing the soil structure by a vibrator. Results of CPTu and Medusa SDMT, executed before and after treatment, are compared to characterize changes in soil structure. The results indicate that the vibration-induced destructuration led to a significant decrease of CPTu measurements, namely tip resistance (qc), sleeve friction (fs) and measured pore pressure (u2), within medium to high sensitive clays. As the decrease in fs is more significant compared to the decrease in qc, a significant decrease in friction ration (Rf) was observed. In analogy, SDMT resulted in a decrease in shear wave velocity (Vs), horizontal stress index (KD) and dilatometer modulus (ED) after the vibro treatment. It was further shown that the soil behaviour type chart according to Robertson (2016) leads to no sufficient characterization of soil structure in soft, marine clays.

  Abstract
  The natural structure of clays has a significant influence on its mechanical behaviour and can be characterized using insitu and laboratory tests. It was reported by Robertson [...]

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• BRIGHT SPARK LECTURE - A Machine Learning Paradigm for Subsurface Stratigraphy from Sparse Data

  C. Shi*

  ISC2024.

  
  

  Abstract

  Subsurface stratigraphy is an indispensable component of geotechnical site characterization and primarily deals with the interpretation of geological interfaces from site-specific measurements, such as boreholes. Traditional geological profiling methods often rely on engineering judgement for manual drawing or entirely depend on parametric models for interpolation. Both approaches face challenges when dealing with limited geo-data. To effectively address the dilemma, a new machine learning paradigm is proposed in this study to combine valuable prior geological knowledge and sparse site-specific measurements for data-driven predictions of both two-dimensional geological cross-sections and threedimensional geological domains. The valuable prior knowledge is quantitatively represented as training images, which are compiled and stored in a training image database that is further enriched and augmented by employing deep generative models. Subsequently, the optimal training images that are compatible with the available site-specific data are adaptively selected for onward stochastic predictions under the framework of non-parametric Bayesian analysis. The method has been successfully applied to tackle geological profiling challenges in Hong Kong. The proposed framework is demonstrated to be capable of not only predicting the most probable geological patterns but also effectively quantifying associated stratigraphic uncertainty. The framework holds great potential of revolutionizing current engineering practices

  Abstract
  Subsurface stratigraphy is an indispensable component of geotechnical site characterization and primarily deals with the interpretation of geological interfaces from site-specific [...]

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