Eolien: la mer n’appartient pas qu’aux pêcheurs! - Challenges

Eolien: la mer n’appartient pas qu’aux pêcheurs! - Challenges

La France a pris un retard considérable dans l’implantation de l’éolien marin pourtant plus efficace que l’éolien terrestre et indispensable à notre mix énergétique. Derniers opposants en date les pêcheurs. Pourtant des solutions existent pour mettre tout le monde d’accord.

Plastiques et Composites : recyclés ou biosourcés ? | Techniques de l'Ingénieur

Plastiques et Composites : recyclés ou biosourcés ? | Techniques de l'Ingénieur

En partenariat avec le Cetim, Techniques de l'Ingénieur vous présente : Plastiques et Composites : recyclés ou biosourcés ? Mercredi 19 Mai 2021 De 10h00 à 11h30

Continuous fibre-reinforced thermoplastic acrylic-matrix composites prepared by liquid resin infusion – A review - ScienceDirect

Continuous fibre-reinforced thermoplastic acrylic-matrix composites prepared by liquid resin infusion – A review - ScienceDirect

Increasing demand for lightweight materials is a major driving force for the steady growth of the continuous fibre-reinforced polymer composite industry. In recent years, strict global targets demanding greater environmental responsibility have led to a shift in research focus to address the end-of-life challenges posed by the use of thermoset matrices.....

Materials | Free Full-Text | Sustainable End-of-Life Management of Wind Turbine Blades: Overview of Current and Coming Solutions

Materials | Free Full-Text | Sustainable End-of-Life Management of Wind Turbine Blades: Overview of Current and Coming Solutions

Various scenarios of end-of-life management of wind turbine blades are reviewed. “Reactive” strategies, designed to deal with already available, ageing turbines, installed in the 2000s, are discussed, among them, maintenance and repair, reuse, refurbishment and recycling. The main results and challenges of “pro-active strategies”, designed to ensure recyclability of new generations of wind turbines, are discussed. Among the main directions, the wind turbine blades with thermoplastic and recyclable thermoset composite matrices, as well as wood, bamboo and natural fiber-based composites were reviewed. It is argued that repair and reuse of wind turbine blades, and extension of the blade life has currently a number of advantages over other approaches. While new recyclable materials have been tested in laboratories, or in some cases on small or medium blades, there are remaining technological challenges for their utilization in large wind turbine blades. View Full-Text

Dynamic Analysis of the Optimized Savonius Vertical Axis Wind Turbine Composite Blades | J. Sol. Energy Eng. | ASME Digital Collection

Dynamic Analysis of the Optimized Savonius Vertical Axis Wind Turbine Composite Blades | J. Sol. Energy Eng. | ASME Digital Collection

This article presents a comprehensive study of the dynamic behavior of small vertical-axis wind turbines (VAWTs) based on local fabricated Savonius VAWTs, which is suitable for countries that have a moderate wind speed. The merits of this design are cleanliness, silent, start-up under low wind speed, independent wind directions, adaptability, and ease of manufacturing. Also, this article presents an experimental validation study for the optimized Savonius VAWT....

Using laminate hybridisation (CFRP-GFRP) and shaped CFRP plies to increase plate post-buckling strain to failure under shear loading - ScienceDirect

Using laminate hybridisation (CFRP-GFRP) and shaped CFRP plies to increase plate post-buckling strain to failure under shear loading - ScienceDirect

Previous works have established the response and failure behaviour of hybrid (CFRP-GFRP) laminates when subjected to a wide range of destabilising loads. However, to date no works have quantified the influence of selective laminate shapes and hybridisation on plate post-buckling strain to failure. Thus, this paper investigates the plate collapse behaviour of a novel X-braced hybrid (CFRP-GFRP) twill woven laminate, subjected to in-plane shear loading. An experimental and numerical investigation is undertaken, including the consideration of a baseline pure CFRP laminate design.....

Observing progressive damage in carbon fiber epoxy laminate composites via 3D in-situ X-ray tomography - ScienceDirect

Observing progressive damage in carbon fiber epoxy laminate composites via 3D in-situ X-ray tomography - ScienceDirect

As the use of fiber-reinforced polymer composites grows in aerospace structures, there is an emerging need to implement damage tolerant approaches. The use of in-situ synchrotron X-ray tomography enables direct observations of progressive damage relative to the microstructural features, which are studied in a T650/5320 laminate composite with two layups via monotonic tension. Specifically, the interactions of micromechanical damage mechanisms at the notch tip were analyzed through 3D image processing as the crack grew. The analysis showed intralaminar cracking was dominant during crack initiation, delamination became prevalent during the later stages of crack progression, and fiber breakage was, in general, largely related to intralaminar cracking.

Investigation of the Ballistic Performance of GFRP Laminate under 150 m/s High-Velocity Impact: Simulation and Experiment

 Investigation of the Ballistic Performance of GFRP Laminate under 150 m/s High-Velocity Impact: Simulation and Experiment

Hybrid Plastics and Natural Materials

 Hybrid Plastics and Natural Materials

A Roya, A Naskara, A Ghosha, J Adhikaria, P Sahac…

Fatigue damage growth and fatigue life of unidirectional composites - ScienceDirect

Fatigue damage growth and fatigue life of unidirectional composites - ScienceDirect

A micromechanical model is developed for the prediction of the growth rate of fatigue damage zones in unidirectional fibre composites subjected to cyclic tension-tension loading. The fatigue damage occurs by progressive fibre breaks caused by the debond crack tip stress fields of fibres that have broken in earlier load cycles. The debond crack tips are taken to advance along the broken fibres due to a cyclic slip-induced decrease in the frictional sliding shear stress acting along the debonded parts of the fibres that undergo repeated forward and reverse slip. The fatigue life is calculated as the number of load cycles for damage zones to reach a critical size where rapid composite failure can occur by longitudinal splitting cracks connecting damage zones within the specimen. A parameter study is performed to explore how the damage growth rate and fatigue life depend on microscale parameters (mechanical properties of fibre, matrix and fibre/matrix interface).

Recycling of thermosetting composites for wind blade application - ScienceDirect

Recycling of thermosetting composites for wind blade application - ScienceDirect

It is well known that wind energy could represent a promising solution to the continuous increase of energy demand in the modern society. At the end of 2016 the European wind power amounted to 153.7 GW, distributed on 77,000 wind turbines and corresponding to the 10.4% of the electrical energy supplied. Considering the EU program to increase the renewable energy share to 27% by 2030, the key role of the wind energy in the next decade is clear. As the number of wind towers that will be dismantled in the next years will continuously increase, the development of sustainable practices to dispose of these plants at the end of their life is of utmost importance....

Solid particle erosion of graphene-based coatings - ScienceDirect

Solid particle erosion of graphene-based coatings - ScienceDirect

Solid particle erosion experiments have been conducted to study the erosion behavior of multiple graphene-based coatings. In this paper, the effects of three factors on the erosion resistance have been investigated: (1) The effect of using graphene-based coatings (2) The effect of using single and multilayer coatings with alternating graphene and polyurethane layers, (3) The effects of angles of attack and erosion duration on the single and multilayer graphene coatings. The investigation also explored the coating surface quality, adhesion, and coating hardness. Finally, two parameters were used to evaluate the efficiency of the coating systems: Material removal and the depth of the erosion scar.....

Wind Turbine Blade Aerodynamic Efficiency Enhancement Efforts-A Compiled Review

Wind Turbine Blade Aerodynamic Efficiency Enhancement Efforts-A Compiled Review PDF

S Gomathinayagam, FD General - NATIONAL INSTITUTE OF WIND ENERGY, 2021

Performance estimation and redesign of horizontal axis wind turbine (HAWT) blade - ScienceDirect

Performance estimation and redesign of horizontal axis wind turbine (HAWT) blade - ScienceDirect

The present global energy crisis has pushed the human race to its limit in search of alternative sources of energy. Wind turbine technology has seen continuous developments ever since the humankind has been on the lookout for harnessing the wind energy. The modern design analysis tools and the emergence of new materials have enabled the development of state-of-the-art wind turbines. The main power-producing component in the turbine is none other than the blade itself which has undergone a major design improvement in the recent past.....

Leading edge erosion of coated wind turbine blades: Review of coating life models - ScienceDirect

Leading edge erosion of coated wind turbine blades: Review of coating life models - ScienceDirect

Erosion of the leading edge of wind turbine blades by droplet impingement wear, reduces blade aerodynamic efficiency and power output. Eventually, it compromises the integrity of blade surfaces. Elastomeric coatings are currently used for erosion resistance, yet the life of such coatings cannot be predicted accurately. This review paper gives an overview of experimentally validated erosion model blocks that can be used to predict the life of the leading edge of coated wind turbine blades. From the reviewed work it is concluded that surface fatigue, as nucleating wear mechanism for erosion damage, can explain erosive wear and failure of the coatings. An engineering approach to surface fatigue, using the Palmgren–Miner rule for cumulative damage, allows for the construction of a rain erosion incubation period equation. ......

Physique du moulage des composites structuraux - Aspects théoriques : Dossier complet | Techniques de l’Ingénieur

Physique du moulage des composites structuraux - Aspects théoriques : Dossier complet | Techniques de l’Ingénieur

Matériaux extrêmement polyvalents, les composites à matrice polymère sont façonnables selon l’application et les propriétés recherchées. Le mode d’élaboration s’avère donc extrêmement déterminant dans la chaîne de conception, puisqu’il détermine les performances du composite. Cet article analyse les différents phénomènes mis en jeu dans les technologies de fabrication des composites avancés. Il en présente des modèles descriptifs découlant des lois de conservation (masse, énergie) et des lois constitutives (viscosité, réactivité, contraintes mécaniques…).

Recycling of thermosetting composites for wind blade application - ScienceDirect

Recycling of thermosetting composites for wind blade application - ScienceDirect

It is well known that wind energy could represent a promising solution to the continuous increase of energy demand in the modern society. At the end of 2016 the European wind power amounted to 153.7 GW, distributed on 77000 wind turbines and corresponding to the 10.4% of the electrical energy supplied. Considering the EU program to increase the renewable energy share to 27% by 2030, the key role of the wind energy in the next decade is clear. As the number of wind towers that will be dismantled in the next years will continuously increase, the development of sustainable practices to dispose of these plants at the end of their life is of utmost importance......

Structural design and optimization of a series of 13.2 MW downwind rotors - Shulong Yao, Mayank Chetan, D Todd Griffith, 2021

Structural design and optimization of a series of 13.2 MW downwind rotors - Shulong Yao, Mayank Chetan, D Todd Griffith, 2021

The quest for reduced LCOE has driven significant growth in wind turbine size. A key question to enable larger rotor designs is how to configure and optimize structural designs to constrain blade mass and cost while satisfying a growing set of challenging structural design requirements. In this paper, we investigate the performance of a series of three two-bladed downwind rotors with different blade lengths (104.3-m, 122.9-m, and 143.4-m) all rated at 13.2 MW. The primary goals are to achieve 25% rotor mass and 25% LCOE reduction. A comparative analysis of the structural performance and economics of this family rotors is presented. To further explore optimization opportunities for large rotors, we present new results in a root and spar cap design optimization. In summary, we present structural design solutions that achieve 25% rotor mass reduction in a SUMR13i design (104.3-m) and 25% LCOE reduction in a SUMR13C design (143.4-m).

LEADING EDGE EROSION OF WIND TURBINE BLADES: Understanding, prevention and protection - ScienceDirect

LEADING EDGE EROSION OF WIND TURBINE BLADES: Understanding, prevention and protection - ScienceDirect

Surface erosion of wind turbine blades is one of rather critical problems of the wind energy development. In this overview paper, recent studies in the mechanisms, modelling and possibilities of preventing the surface erosion of wind turbine blades are discussed. Latest research in the area of leading edge erosion (LEE) from different viewpoints, based on meteorology, aerodynamics, materials science, computational mechanics are summarized. Technologies of experimental testing of anti-erosion coatings, effect of leading edge erosion on aerodynamics of wind turbines, roughness and its evolution are discussed, as well as meteorological aspects, parameters and characteristics of precipitation, possibilities of prediction of rain and hail and regional differences. Further, computational models of LEE and directions of the development of anti-erosion coatings are presented.

Carbon Fiber Composites | SpringerLink

Carbon Fiber Composites | SpringerLink

Composites are a group of materials that mainly constitutes metals, ceramics, and/or polymers in order to improve the composite properties. Usually, some stiffer, stronger materials are used as reinforcing agents in the composite matrix to enhance the mechanical and thermal behavior of the composite materials. Carbon fibers are the major load-bearing components in most of the composites.