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Search results for: SPAR PLATFORMS, HEAVE PLATES, HYDRODYNAMIC COEFFICIENT, FLOATING OFFSHORE WIND TURBINES (FOWTS)
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Selected problems concerning strength of a floating dock with roof
PublicationW pracy przedstawiono modele i wyniki analizy wytrzymałości konstrukcji zadaszonego doku pływającego. Obliczono, że ścianki wiązarów zadaszenia, aby mogły przenieść obciążenia środowiskowe, muszą mieć grubość 24 mm. Ciężkie przesuwne segmenty zadaszenia generują w dennikach pontonu doku naprężenia sięgające 25% wartości dopuszczalnych. Wytężenie konstrukcji pontonu doku i podbudowy, obciążonych ciężarem zadaszenia i dokowanego...
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Hydrodynamical loads on a floating dock towed in sea conditions
PublicationPrzedstawiono i analizowano charakterystyki amplitudowe (RAO) oraz prognozy krótko i długoterminowe hydrodynamicznych reakcji doku pływającego holowanego w warunkach morskich na akwenach Bałtyku i Morza Północnego. Przedmiotem badań były: nurzania i kołysania wzdłużne, ciśnienia dynamiczne indukowane w różnych częściach dna doku, pionowy moment gnący i opór doku holowanego na falach czołowych. Charakterystyki RAO rozpatrywanych...
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Digital Platforms and Services - STAC - 2023/2024 - KOPIA
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Prediction of flow boiling heat transfer coefficient for carbon dioxide in minichannels and conventional channels
PublicationIn the paper presented are the results of calculations using authors own model to predict heat transfer coefficient during flow boiling of carbon dioxide. The experimental data from various resea rches were collected. Calculations were conducted for a full range of quality variation and a wide range of mass velocity. The aim of the study was to test the sensitivity of the in-house model. The results show the importance of taking into...
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Integration and Visualization of the Results of Hydrodynamic Models in the Maritime Network-Centric GIS of Gulf of Gdansk
PublicationEnsuring of security in the coastal area makes on a seaside countries research in the field of infrastructure spatial information of environmental data. The paper presents the results of work on the construction of this infrastructure by integrating electronic navigational chart with ortophotomaps of coastal areas as well as numerical data from weather and hydrodynamic models. Paper focuses on a problems associated with creating...
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ADAPTATION OF ENGINEERING FEA-BASED ALGORITHMS TO LCF FAILURE AND MATERIAL DATA PREDICTION IN OFFSHORE DESIGN
PublicationThere is an ever growing industrial demand for quantitative assessment of fatigue endurance of critical structural details. Although FEA-based calculations have become a standard in engineering design, problems involving the Low-To-Medium cycle range (101-104) remain challenging. This paper presents an attempt to optimally choose material data, meshing density and other algorithm settings in the context of recent design of the...
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Dynamic analysis of the impact of the wind spectrum according to the theory of Davenport for lightweight structures of the roof in sports hall Czyzyna in Cracow.
PublicationThe main aim of this analysis is to characterize numerical simulations connected with modeling dynamic influence of wind on the lightweight structures of the roof in sports hall – “Czyżyna”. This hall is built in Cracow. The article also involves the proposals of the solutions connected with dynamic influence of the wind – Davenport’s method has been used. These proposals have not been taken into consideration at the detailed engineering...
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Temperature Coefficient of Electronic Polarizability in Thin Polymer Films Deposited on Si and SiO2 Substrates Determined via Spectroscopic Ellipsometry
PublicationEllipsometry is widely used to determine the thermo-optical properties of thin polymer films. However, if the thermo-optic coefficient (TOC) and the linear thermal expansion coefficient (LTEC) are to be used to determine the temperature coefficient of electronic polarizability (TCEP) in thin polymer films, their values must be determined with the greatest possible accuracy, as both have the opposite effect. In this article,...
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Impact of abiotic stressors on nutrient removal and rhizomicrobiome composition in floating treatment wetland with Equisetum hyemale
PublicationFloating treatment wetlands (FTW) are receiving growing interest as a phyto-technology. However, there are significant research gaps regarding the actual role of plant species and plant-microbiome interactions. In this study, the nutrient uptake of Equisetum hyemale was examined in FTW microcosms under the influence of abiotic stressors: As (3 mg/L) and Pb (3 mg/L) as well as Cl− (300 and 800 mg/L) in reference to a control during...
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Field tests on hydrodynamic and hybrid operation of a bi-directional thrust bearing of a pump-turbine
PublicationIn vertical shaft pump turbines operating in pumped storage power plants an important role is played by a thrust bearing. Because of bi-directional character of operation, thrust bearing tilting pads have to be supported symmetrically, which is known to be unfavourable from the point of view of their performance. Large thrust bearings have to be carefully designed so as to minimise excessive thermo-elastic pad deformations. The...
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Artificial Neural Network based fatigue life assessment of riveted joints in AA2024 aluminum alloy plates and optimization of riveted joints parameters
PublicationThe objective of this paper is to provide the fatigue life of riveted joints in AA2024 aluminum alloy plates and optimization of riveted joints parameters. At first, the fatigue life of the riveted joints in AA2024 aluminum alloy plates is obtained by experimental tests. Then, an artificial neural network is applied to estimate the fatigue life of riveted lap joints based on the number of lateral and longitudinal holes, punch pressure,...
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The experimental identification of the dynamic coefficients of two hydrodynamic journal bearings operating at constant rotational speed and under nonlinear conditions.
PublicationHydrodynamic bearings are commonly used in ship propulsion systems. Typically, they are calculated using numerical or experimental methods. This paper presents an experimental study through which it has been possible to estimate 24 dynamic coefficients of two hydrodynamic slide bearings operating under nonlinear conditions. During the investigation, bearing mass coefficients are identified by means of a newly developed algorithm....
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Investigation of hydrodynamic clutch with a magnetorheological fluid
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Hydrodynamic model experiments with POD propulsors
PublicationPrzedstawiono serię badań modelowych dwóch pędników podowych. Pędniki te zostały zaprojektowane i zbudowane dla dwóch wersji dużego, załogowego modelu statku przeznaczonego do prób manewrowych. Jedna wersja ma pędnik pojedynczy a drugi układ dwupędnikowy. Obydwa modele były badane w kanale obiegowym. Celem eksperymentu było zmierzenie sześciu składowych siły i momentu hydrodynamicznego na pędniku w funkcji współczynnika posuwu...
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Design criterion for hydrodynamic vortex separators
PublicationTechnical objects designing involves determination of geometrical parameters that characterize a given object. When the device is described by the differential equations, an inverse problem brings difficulties, as geometrical values sought condition the solution to the problem. Vortex separators can be designed by the "criterion method'. Firstly, a critical particle is distinguished such that bigger particles are removed from...
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Combination of hydrodynamic cavitation and SR-AOPs for simultaneous degradation of BTEX in water
PublicationHydrodynamic cavitation (HC) is an emerging technology gaining interest in water treatment for use in elimination of a wide range of organic pollutants. The energy released during cavitation phenomenon has number of applications and, particularly, it can be utilized for activation of persulfate (PS) and peroxymonosulfate (PMS). In the present study, hybrid techniques: HC combined with persulfates – HC-PS and HC-PMS were tested...
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Plasticity of Bead-On-Plate Welds Made with the Use of Stored Flux-Cored Wires for Offshore Applications
PublicationExtreme atmospheric conditions in the marine and offshore industry are harmful to engineering materials, especially to welded joints, and may cause degradation of their properties. This article presents the results of research on the plasticity of bead-on-plate welds made using two types of seamless, copper plated flux-cored wires. Before welding, spools with wire were stored for 1 month in two distinct locations with different...
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Supervisory control of wind farm
PublicationW artykule przedstawiono układ nadrzędnej regulacji farmy wiatrowej umożliwiający minimalizację wahań mocy czynnej na wyjściu farmy wiatrowej.
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Innovative Resistojet Propulsion System—Use in Robotic Space Platforms
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DECISION - MAKING IN VIRTUAL SOFTWARE TEAMS USING CLOUD PLATFORMS
PublicationSoftware development projects are usually realized by traditional or virtual IT teams using computing clouds. Team collaboration requires decision - making regarding essential aspects of a project progress. The article concerns methods of decision – making process in the case of traditional and virtual teams’ work. The research results conducted in a group of IT specialists are presented, and to analyze their preferences in decision-making...
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The role of hydrodynamic cavitation in tuning physicochemical properties of food items: A comprehensive review
PublicationBackground: Today, food processing industries are looking for alternative technologies with an eco-friendly character for the processing of food, beverages and agricultural crops. Ideally, such technologies may preserve the original properties of the food products while reaching their primary target of application. Scope and approach: At this point, hydrodynamic cavitation (HC) is recognized as one of the potential technologies...
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Displacement Sensors Based on the Phase of the Reflection Coefficient of a Split Ring Resonator Loaded Transmission Line
Publication— In this paper, novel displacement sensors using a microstrip loaded with a pair of split ring resonators (SRRs) are proposed. It is shown that the phase of the reflection coefficient from the loading SRRs can be used for displacement sensing. The paper also proposes a differential version of the sensor that benefits from a higher sensitivity and reference zero, which is useful for alignment purposes. It is further shown that...
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Strucutral steel - tensile test results
Open Research DataModern floating structures such as ships, oil platforms and offshore wind towers are built mostly of structural steel. It is a material that is subject to requirements which, when met, allows the construction and safe operation of the structure throughout its entire work cycle. One of the basic criteria that a material must meet is its strength. The...
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Critical Reappraisal of Casagrande and Taylor Methods for Coefficient of Consolidation
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Integration Data Model of the Bathymetric Monitoring System for Shallow Waterbodies Using UAV and USV Platforms
PublicationChanges in the seafloor relief are particularly noticeable in shallow waterbodies (at depths up to several metres), where they are of significance for human safety and environmental protection, as well as for which the highest measurement accuracy is required. The aim of this publication is to present the integration data model of the bathymetric monitoring system for shallow waterbodies using Unmanned Aerial Vehicles (UAV) and...
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Investigation of ecological parameters of a gas turbine combustion chamber with steam injection for the floating production, storage, and offloading vessel
PublicationThe article is dedicated to the investigation of the possibility of using the contact type gas turbine cycle with steam injection into the combustion chamber for the floating production, storage, and offloading vessel in order to increase the specific power and efficiency and reduce emissions of toxic components. A new approach is proposed, associated with the use of the two-stage injection of superheated steam into a gas turbine...
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Detection of Delamination in Laminate Wind Turbine Blades Using One-Dimensional Wavelet Analysis of Modal Responses
PublicationThis paper demonstrates the effectiveness of a nondestructive diagnostic technique used to determine the location and size of delamination in laminated coatings of wind turbine blades. This is realized based on results of numerical and experimental investigations obtained by the use of the finite element method (FEM) and laser scanning vibrometry (LSV). The proposed method is based on the one-dimensional continuous wavelet transform...
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Using Statistical Methods to Estimate The Worst Case Response Time of Network Software Running on Indeterministic Hardware Platforms
PublicationIn this paper we investigate whether the statistical Worst Case Execution Time (WCET) estimation methods devised for embedded platforms can be successfully applied to find the Worst Case Response Time (WCRT) of a network application running on a complex hardware platform such as a contemporary commercial off-the-shelf (COTS) system. Establishing easy-to-use timing validation techniques is crucial for real-time applications and...
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Design and numerical study of turbines operating with MDM as working fluid
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Floating treatment wetland with Equisetum hyemale - performance in nutrients and potentially toxic elements removal
Open Research DataThis data set contains the results of a microcosm experiment with floating treatment wetlands (FTW) conducted under artificial conditions. The goal of this experiment was to determine the effect of stress factors (Pb, As, increased salinity) on the nutrient uptake capacity of Equisetum hyemale in FTW. The ability of E.hyemale to uptake Pb and As was...
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INTERNATIONAL JOURNAL OF OFFSHORE AND POLAR ENGINEERING
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Wind tunnel experiments and numerical analysis of the wind load on double-shell cylindrical, vertical tanks
PublicationW pracy przedstawiono wyniki badań modelowych w tunelu aerodynamicznym oraz symulacji komputerowych obciążenia wiatrem pionowych, walcowych zbiorników dwupłaszczowych z dachem pływającym. W badaniach modelowych analizowano wpływ rozstawu między płaszczami zbiornika na wartość i rozkład współczynnika ciśnienia na płaszczach oraz dachu pływającym. Wyniki symulacji komputerowych przeprowadzonych w programie Fluent porównano z wynikami...
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An innovative method of measuring the extension of the piston rod in hydraulic cylinders, especially large ones used in the shipbuilding and offshore industry
PublicationThe article presents the results of selected works related to the wider subject of research conducted at the Faculty of Mechanical Engineering and Shipbuilding at the Gdańsk University of Technology, regarding designing various on board devices with hydraulic drive for ships and other offshore facilities. One of the commonly used these mechanisms are hydraulic actuators with the measurement of the piston rod extension. The issue...
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Non-Destructive Diagnostics of Concrete Beams Strengthened with Steel Plates Using Modal Analysis and Wavelet Transform
PublicationExternally bonded reinforcements are commonly and widely used in civil engineering objects made of concrete to increase the structure load capacity or to minimize the negative effects of long-term operation and possible defects. The quality of adhesive bonding between a strengthened structure and steel or composite elements is essential for effective reinforcement; therefore, there is a need for non-destructive diagnostics of adhesive...
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Stateczność i niezawodność pełnomorskich platform wiertniczych
PublicationW pracy przedstawiono wieloletnie doświadczenia Autora w zakresie wybranych aspektów numerycznej analizy pełnomorskich platform wiertniczych, w szczególności stacjonarnych platform stalowych poddanych działaniu fal wiatrowych i wiatru. W opisie zachowania się platform uwzględniono współoddziaływanie trzech ośrodków: materiału konstrukcji, morskich fal wiatrowych i podłoża gruntowego. Przyjęcie do opisu stochastycznych właściwości...
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Hydrodynamic reanalysis of currents in the Baltic Sea using the PM3D model
Open Research DataThe dataset contains the results of numerical modeling of currents in the Baltic Sea since 1998. A long-term reanalysis was performed using a three-dimensional hydrodynamic model PM3D (Kowalewski and Kowalewska-Kalkowska, 2017), a new version of the M3D model (Kowalewski, 1997).
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The Role of Molecular Structure in Monte Carlo Simulations of the Secondary Electron Yield and Backscattering Coefficient from Methacrylic Acid
PublicationIn this paper, we show the influence of the chemical structure of four different conformers on the secondary electron emission and backscattering of an electron beam from a gel of methacrylic acid. The conformers have different permanent dipole moments, which determines the cross sections for elastic collisions with electrons. The cross sections are used in Monte Carlo simulations of an electron beam, which enters the gel of methacrylic...
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ANALYSIS OF BEARING CLEARANCE AND WIDTH OF OIL GROOVE ON CHARACTERISTIC OF FLUID FILM IN HYDRODYNAMIC MAIN CRANKSHAFT BEARINGS
PublicationAbstract Paper represents analysis of influence of oil groove width and bearing clearance on characteristics of oil film in hydrodynamic journal main crankshaft bearing. Analysis was performed in purpose to define influence of bearing clearance and dimensions of oil groove on static characteristics and manufacturability of half shelf bearings in industrial high-volume production. Computer simulations was made using ARTbear program...
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Comparative analysis of the flow control over a circular cylinder with detached flexible and rigid splitter plates
PublicationA comparative study is performed on a circular cylinder with both flexible and rigid splitter plates (SPs). This study has the novelty of using single and dual detached SPs located downstream of the cylinder. The dimensionless gap distance between the first splitter plate and the cylinder as well as the distance between the SPs are varied. The strain of flexible SPs can be used for energy harvesting from the flow. Therefore, a...
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Fixed roof to shell connection in tank with an internal floating cover.
PublicationReferat dotyczy projektowania połączenia dachu stałego zbiornika walcowego z płaszczem w przypadku zastosowania wewnętrznego przekrycia pływającego. Zaproponowano zastosowanie dodatkowego pierścienia usztywniającego, zabezpieczającego górną krawędź płaszcza zbiornika. Wyniki analiz z zastosowaniem metody elementów skończonych zamieszczono w formie map naprężeń.
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A design concept of fire protection system for an ecological floating dock
PublicationW artykule przedstawiono możliwe do wystąpienia na doku pływającym zagrożenie pożarowe oraz projekt koncepcyjny systemu zabezpieczenia przeciwpożarowego. Projekt ten obejmuje: istalację gaśniczą wodno-hydrantową i pianową do ochrony pokładu głównego oraz instalację CO2 do ochrony siłowni, rozdzielni elektrycznej i tunelu kablowego, a także instalację wykrywania i sygnalizacji pożaru.
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Agent-Based Approach to RBF Network Training with Floating Centroids
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High-Resolution Wind Wave Parameters in the Area of the Gulf of Gdańsk During 21 Extreme Storms
PublicationThis dataset contains the results of wind-wave parameter modelling in the area of the Gulf of Gdańsk (Southern Baltic). For the simulations, a high resolution SWAN model was used. The dataset consists of the significant wave height, the direction of the wave approaching the shore and the wave period during 21 historical, extreme storms. The storms were selected by an automatic search over the 44-year-long significant wave height...
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Discrepancies of energy values in dynamics of three intersecting plates
PublicationW pracy analizuje się lot konstrukcji powłokowej złożonej z trzech przecinających się powłok. Obciążeniem jest przestrzenny układ sił o zadanym trójkątnym przebiegu w czasie. Po ustaniu obciążenia powłoka doświadcza swobodnego lotu. Celem pracy jest dyskusja różnic wartości energii całkowitej układu w locie swobodnym jakie znane są w literaturze przedmiotu. W pracy przedstawiono także przykład weryfikujący zastosowane algorytmy...
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Experiments on damage development in metallic plates subjected to explosions
PublicationW pracy przedstawiono badania eksperymentalne rozwoju zniszczenia płyt metalowych pod wpływem eksplozji. Zaprezentowano opis badan statycznych i dynamicznych na płytach oraz opis badan jednoosiowych. Dla założonego modelu równania konstytutywnego przedstawiono sposób identyfikacji parametrów materiałowych.
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Plastic ductile damage evolution and collapse of plates and shells.
PublicationPraca jest poswięcona problemowi numerycznej symulacji zniszczenia w płytach i powłokach z uwzględnieniem efektów nieliniowości geometrycznej i materialowej. Uwzględniono skończone przemieszczenia i obroty; przyjęty model materiałowy obejmuje zachowanie sprężysto-plastyczne, wzmocnienie izotropowe i kinematyczne, oraz zniszczenie ciągliwe. Specjalną uwagę poświecono problemom lokalizacji zniszczenia, rozwoju zniszczenia oraz całkowitej...
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Nonlocal Models of Plates and Shells with Applications in Micro- and Nanomechanics
PublicationNowadays, the use of small-scale structures in micro/nanomachines has become more and more widespread. The most important applications of such small-sized parts are in micro-electro-mechanical systems (MEMS) as well as nano-electro-mechanical systems (NEMS) as actuators, sensors, energy harvesters. For example, nanosensors are nanoscale devices that measure physical quantities and convert these to signals that can be detected and...
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GIS-based hydrodynamic modeling for urban flood mitigation in fast-growing regions: a case study of Erbil, Kurdistan Region of Iraq
PublicationFloods threaten urban infrastructure, especially in residential neighborhoods and fast-growing regions. Flood hydrodynamic modeling helps identify flood-prone locations and improve mitigation plans' resilience. Urban floods pose special issues due to changing land cover and a lack of raw data. Using a GIS-based modeling interface, input files for the hydrodynamic model were developed. The physical basin's properties were identified...
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Bone healing under different lay‐up configuration of carbon fiber‐reinforced PEEK composite plates
PublicationSecondary healing of fractured bones requires an application of an appropriate fixa-tor. In general, steel or titanium devices are used mostly. However, in recent years,composite structures arise as an attractive alternative due to high strength to weightratio and other advantages like, for example, radiolucency. According to Food andDrug Administration (FDA), the only unidirectionally reinforced composite allowed tobe implanted...
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Stiffness assessment of the laminate recovered from end-of-life wind turbine blade
PublicationIn the paper the stiffness parameters of the laminate recovered from an aerodynamic shell of a decommissioned wind turbine blade are evaluated. The aim of the work is to assess selected methods for identifying material data, as well as to estimate the level of stiffness degradation during turbine operation. Several practical identification methods are presented and compared. Two concepts of a single laminate layer are considered,...