Bio-inspired self-healing polymer foams with bilayered capsule systems - ScienceDirect
Bio-inspired, self-healing polymer foams containing novel calcium-alginate capsule system was developed for load-bearing application. The capsules were created by a multi-stage encapsulating process that can encapsulate two mutually reactive healing agents within single capsules....
30 avril 2020
29 avril 2020
Non-destructive thermography-based system for damage localisation and characterisation during induction welding of thermoplastic composites
Non-destructive thermography-based system for damage localisation and characterisation during induction welding of thermoplastic composites
In the last decades, advanced thermoplastics matrix composites (TPCs) were recognised as a valid alternative to thermosetting matrices for many advanced applications. One of the advantages in the use of TPCs is the capability to perform fusion bonding which avoids the use of external joints. Induction welding of carbon fiber reinforced TPCs has gained large interest thanks to the minimum surface preparation required, high efficiency and capability to localise heat at the welding surface.....
In the last decades, advanced thermoplastics matrix composites (TPCs) were recognised as a valid alternative to thermosetting matrices for many advanced applications. One of the advantages in the use of TPCs is the capability to perform fusion bonding which avoids the use of external joints. Induction welding of carbon fiber reinforced TPCs has gained large interest thanks to the minimum surface preparation required, high efficiency and capability to localise heat at the welding surface.....
15 avril 2020
Materials | Free Full-Text | Non-Conventional Deformations: Materials and Actuation
Materials | Free Full-Text | Non-Conventional Deformations: Materials and Actuation
This paper reviews materials and structures displaying non-conventional deformations as a response to different actuations (e.g., electricity, heat and mechanical loading). Due to the various kinds of actuation and targeted irregular deformation modes, the approaches in the literature show great diversity. Methods are systematized and tabulated based on the nature of actuation. Electrically and mechanically actuated shape changing concepts are discussed individually for their significance, while systems actuated by heat, pressure, light and chemicals are condensed in a shared section presenting examples and main research trends. Besides scientific research results, this paper features examples of real-world applicability of shape changing materials, highlighting their industrial value. View Full-Text
This paper reviews materials and structures displaying non-conventional deformations as a response to different actuations (e.g., electricity, heat and mechanical loading). Due to the various kinds of actuation and targeted irregular deformation modes, the approaches in the literature show great diversity. Methods are systematized and tabulated based on the nature of actuation. Electrically and mechanically actuated shape changing concepts are discussed individually for their significance, while systems actuated by heat, pressure, light and chemicals are condensed in a shared section presenting examples and main research trends. Besides scientific research results, this paper features examples of real-world applicability of shape changing materials, highlighting their industrial value. View Full-Text
Current status of carbon fibre and carbon fibre composites recycling - ScienceDirect
Current status of carbon fibre and carbon fibre composites recycling - ScienceDirect
The rapid rise in the applications of carbon fibre reinforced polymer matrix composites (CFRPs) is creating a waste recycling challenge. The use of high-performance thermoset polymers as the matrix makes the recovery of the fibres and the resins extremely difficult......
The rapid rise in the applications of carbon fibre reinforced polymer matrix composites (CFRPs) is creating a waste recycling challenge. The use of high-performance thermoset polymers as the matrix makes the recovery of the fibres and the resins extremely difficult......
Thesis - Experimental and numerical investigation on the mechanical and dynamic performance of flax/E-glass hybrid composites - ePrints Soton
Experimental and numerical investigation on the mechanical and dynamic performance of flax/E-glass hybrid composites - ePrints Soton
Industry demand for natural fibres has been growing due to social awareness and environmental legislations. For example, the European Waste Framework Directive and the Department of Agriculture and the US Department of Energy have set targets to compel industries towards environmentally friendly materials in various sectors. Along with metals, composite materials are utilized in various applications and the fibres mostly used in these applications are widely E-glass and carbon fibres......
Industry demand for natural fibres has been growing due to social awareness and environmental legislations. For example, the European Waste Framework Directive and the Department of Agriculture and the US Department of Energy have set targets to compel industries towards environmentally friendly materials in various sectors. Along with metals, composite materials are utilized in various applications and the fibres mostly used in these applications are widely E-glass and carbon fibres......
Improvement of Mechanical and Hydrophobic Properties of Nanotube Reinforced Glass-Fiber Composites - ProQuest
Improvement of Mechanical and Hydrophobic Properties of Nanotube Reinforced Glass-Fiber Composites - ProQuest
An exponential increase in the use of composite materials over the past 70 years makes
them ideal materials to improve the scope for diverse industrial applications. Fiber-reinforced
composites (FRCs) are one of the imperative materials and are used extensively in distinct
engineering fields such as aerospace, automotive, sporting goods, greener energy, and more.
Among the fiber-reinforced composites, Glass Fiber Reinforced Composites (GFRCs) are
finding increased applications due to their high strength-to-weight ratio.....
An exponential increase in the use of composite materials over the past 70 years makes
them ideal materials to improve the scope for diverse industrial applications. Fiber-reinforced
composites (FRCs) are one of the imperative materials and are used extensively in distinct
engineering fields such as aerospace, automotive, sporting goods, greener energy, and more.
Among the fiber-reinforced composites, Glass Fiber Reinforced Composites (GFRCs) are
finding increased applications due to their high strength-to-weight ratio.....
14 avril 2020
Computational modelling of dynamic delamination in morphing composite blades and wings | Fallah | The International Journal of Multiphysics
Computational modelling of dynamic delamination in morphing composite blades and wings | Fallah | The International Journal of Multiphysics
Morphing blades have been promising in lifting restrictions on rated capacity of wind turbines and improving lift-to-drag ratio for aircraft wings at higher operational angles of attack. The present study focuses on one aspect of the response of morphing blades viz. dynamic delamination.
A numerical study of delamination in morphing composite blades is conducted. Both components i.e. the composite part and the stiffener are studied. The eXtended Finite Element Method (XFEM) and nonlocal continuum mechanics (peridynamics) have both been used to study fracture in the isotropic stiffener used in conjunction with the blade. As for the composite morphing blade, cohesive elements are used to represent the interlaminar weak zone and delamination has been studied under dynamic pulse loads. Intraply damage is studied using the nonlocal model as the peridynamic model is capable of addressing the problem adequately for the necessary level of sophistication.
Morphing blades have been promising in lifting restrictions on rated capacity of wind turbines and improving lift-to-drag ratio for aircraft wings at higher operational angles of attack. The present study focuses on one aspect of the response of morphing blades viz. dynamic delamination.
A numerical study of delamination in morphing composite blades is conducted. Both components i.e. the composite part and the stiffener are studied. The eXtended Finite Element Method (XFEM) and nonlocal continuum mechanics (peridynamics) have both been used to study fracture in the isotropic stiffener used in conjunction with the blade. As for the composite morphing blade, cohesive elements are used to represent the interlaminar weak zone and delamination has been studied under dynamic pulse loads. Intraply damage is studied using the nonlocal model as the peridynamic model is capable of addressing the problem adequately for the necessary level of sophistication.
Multi-Surrogate Collaboration Approach for Creep-Fatigue Reliability Assessment of Turbine Rotor - IEEE Journals & Magazine
Multi-Surrogate Collaboration Approach for Creep-Fatigue Reliability Assessment of Turbine Rotor - IEEE Journals & Magazine
The creep-fatigue resistance of turbine rotor seriously affects the reliability performance and service lifetime of aircraft engine. Creep-fatigue reliability assessment is an effective measure to quantify the uncertain creep-fatigue damage and evaluate the creep-fatigue reliable life for turbine rotor. To improve the modeling accuracy and simulation efficiency of creep-fatigue reliability assessment, a multi-surrogate collaboration approach (MSCA) is proposed by absorbing the strengths of the proposed dynamic neural network surrogate (DNNS) into distributed collaborative strategy. The creep-fatigue reliability assessment of a typical turbine rotor is regarded as one case to estimate the presented MSCA with respect to the fluctuations of multi-physical variables and the variabilities of multi-model parameters. The assessment results reveal that the creep-fatigue reliable life of turbine rotor under reliability degree of 0.998 7 is 629 cycles, and the fatigue strength coefficient and holding creep time play a leading role on creep-fatigue reliable life since their effect probabilities of 27 % and 19 %, respectively. Comparison of various methods (direct Monte Carlo simulation, response surface, neural network surrogate, DNNS) shows that the presented MSCA holds high efficiency and accuracy in creep-fatigue reliability assessment of turbine rotor.
The creep-fatigue resistance of turbine rotor seriously affects the reliability performance and service lifetime of aircraft engine. Creep-fatigue reliability assessment is an effective measure to quantify the uncertain creep-fatigue damage and evaluate the creep-fatigue reliable life for turbine rotor. To improve the modeling accuracy and simulation efficiency of creep-fatigue reliability assessment, a multi-surrogate collaboration approach (MSCA) is proposed by absorbing the strengths of the proposed dynamic neural network surrogate (DNNS) into distributed collaborative strategy. The creep-fatigue reliability assessment of a typical turbine rotor is regarded as one case to estimate the presented MSCA with respect to the fluctuations of multi-physical variables and the variabilities of multi-model parameters. The assessment results reveal that the creep-fatigue reliable life of turbine rotor under reliability degree of 0.998 7 is 629 cycles, and the fatigue strength coefficient and holding creep time play a leading role on creep-fatigue reliable life since their effect probabilities of 27 % and 19 %, respectively. Comparison of various methods (direct Monte Carlo simulation, response surface, neural network surrogate, DNNS) shows that the presented MSCA holds high efficiency and accuracy in creep-fatigue reliability assessment of turbine rotor.
Fractographic analysis of sandwich panels in a composite wind turbine blade using optical microscopy and X-ray computed tomography - ScienceDirect
Fractographic analysis of sandwich panels in a composite wind turbine blade using optical microscopy and X-ray computed tomography - ScienceDirect: This study provides a new perspective on the failure of sandwich panels in a composite wind turbine blade. Fractographic characteristics of fracture regions are examined thoroughly using optical microscopy and X-ray computed tomography. The detailed fractographic analysis leads to the identification of the failure modes and failure sequence. This study addresses an important but rarely studied failure process in the sandwich panels cored with grooved foams....
7 avril 2020
US20200080542A1 - Positioning profiles for pultrusions in wind blade spar caps - Google Patents
US20200080542A1 - Positioning profiles for pultrusions in wind blade spar caps - Google Patents
Provided herein is a spar cap having a profile for guiding and receiving a shear web for wind turbine blade. Particularly, the present disclosure provides a pultruded spar cap having a bond gap feature to maintain a uniform space for distribution of bonding paste between the spar cap and shear web. Also, the spar cap is formed with locating features which guide and receive placement of the shear web.
Provided herein is a spar cap having a profile for guiding and receiving a shear web for wind turbine blade. Particularly, the present disclosure provides a pultruded spar cap having a bond gap feature to maintain a uniform space for distribution of bonding paste between the spar cap and shear web. Also, the spar cap is formed with locating features which guide and receive placement of the shear web.
A gravo-aeroelastically scaled wind turbine rotor at field-prototype scale with strict structural requirements - ScienceDirect
A gravo-aeroelastically scaled wind turbine rotor at field-prototype scale with strict structural requirements - ScienceDirect
A new sub-scale field-prototype design solution is developed to realize the dynamics, structural response, and distributed loads (gravitational, aerodynamic, centrifugal) that are characteristic of a full-scale large, modern wind turbine rotor. Prior work in sub-scale wind turbine testing has focused on matching aerodynamic/aero-elastic characteristics of full-scale rotors at wind tunnel scale.....
A new sub-scale field-prototype design solution is developed to realize the dynamics, structural response, and distributed loads (gravitational, aerodynamic, centrifugal) that are characteristic of a full-scale large, modern wind turbine rotor. Prior work in sub-scale wind turbine testing has focused on matching aerodynamic/aero-elastic characteristics of full-scale rotors at wind tunnel scale.....
US20200080543A1 - Temporary web support for wind turbine blade rotating device - Google Patents
US20200080543A1 - Temporary web support for wind turbine blade rotating device - Google Patents
Provided herein is a shear web support for wind turbine blade. Particularly, the present disclosure provides a frangible shear web support element that is designed to fail under certain specific conditions. The frangible support(s) enhance the structural rigidity of the shear web, allow for one-step mold closures, and rupture or disconnect once a predetermined condition (e.g. load threshold, load orientation/vector) is applied to the support element.
Provided herein is a shear web support for wind turbine blade. Particularly, the present disclosure provides a frangible shear web support element that is designed to fail under certain specific conditions. The frangible support(s) enhance the structural rigidity of the shear web, allow for one-step mold closures, and rupture or disconnect once a predetermined condition (e.g. load threshold, load orientation/vector) is applied to the support element.
Analysis of failure modes for a non-crimp basalt fiber reinforced epoxy composite under flexural and interlaminar shear loading - ScienceDirect
Analysis of failure modes for a non-crimp basalt fiber reinforced epoxy composite under flexural and interlaminar shear loading - ScienceDirect
This study investigates the mechanical properties (interlaminar shear and flexural strength) and failure modes of a basalt/epoxy composite, manufactured using a non-crimp-fabric (NCF) with a vacuum assisted resin infusion process. Under flexural bending, damage initiated on the compression side between 20-50% of peak load and progressed from ply to ply with increasing load.....
This study investigates the mechanical properties (interlaminar shear and flexural strength) and failure modes of a basalt/epoxy composite, manufactured using a non-crimp-fabric (NCF) with a vacuum assisted resin infusion process. Under flexural bending, damage initiated on the compression side between 20-50% of peak load and progressed from ply to ply with increasing load.....
WO2020068537 JOINT INTERFACE FOR WIND TURBINE ROTOR BLADE COMPONENTS
WO2020068537 JOINT INTERFACE FOR WIND TURBINE ROTOR BLADE COMPONENTS
A rotor blade component for a wind turbine includes a first structural component, such as a spar cap, formed from a plurality of stacked pultruded members. A second structural component, such as a shear web, is fixed to the first structural component at a joint interface. One or more webs form the joint interface, wherein each of the webs has a first section bonded between at least two of the pultruded members in the first structural component and a second section extending across the joint interface and bonded onto or into the second structural component.
A rotor blade component for a wind turbine includes a first structural component, such as a spar cap, formed from a plurality of stacked pultruded members. A second structural component, such as a shear web, is fixed to the first structural component at a joint interface. One or more webs form the joint interface, wherein each of the webs has a first section bonded between at least two of the pultruded members in the first structural component and a second section extending across the joint interface and bonded onto or into the second structural component.
ASI | Free Full-Text | A Feature-Based Cost Estimation Model for Wind Turbine Blade Spar Caps
ASI | Free Full-Text | A Feature-Based Cost Estimation Model for Wind Turbine Blade Spar Caps
A problem for wind turbine operators is decreasing prices for wind-generated electricity. Many turbines are approaching their rated 20-year lives. A more economically viable and sustainable solution that reduces Levelized Cost of Energy (LCOE) and avoids expensive turbine replacement is retrofitting new spar caps blades. A new cost model assesses the feasibility of retrofitting 35 to 75 m turbines with GFRP (glass fiber reinforced polymer composite) and longer length CFRP (carbon fiber reinforced composite) spar caps. Spar cap cost scales with features such as mass, volume fraction and complexity. Organizational learning is a cost factor. Material and direct labor increase as proportions of total cost while tooling, capital, utilities, and indirect labor decrease. There is good agreement between a manufacturer and the model. Twenty-year turbines were compared with retrofitted spar caps over 25 years for LCOE. Same length GFRP and longer length CFRP spar cap retrofits decrease LCOE. Longer length CFRP spar caps decrease LCOE compared with GFRP retrofits over 25 years. CFRP material cost impacts CFRP retrofit feasibility. Retrofitted turbines must meet engineering, operational performance, and planning requirements criteria. Software algorithms may improve human learning and enable automatic updates from varying design and cost inputs, thereby increasing cost prediction accuracy.
A problem for wind turbine operators is decreasing prices for wind-generated electricity. Many turbines are approaching their rated 20-year lives. A more economically viable and sustainable solution that reduces Levelized Cost of Energy (LCOE) and avoids expensive turbine replacement is retrofitting new spar caps blades. A new cost model assesses the feasibility of retrofitting 35 to 75 m turbines with GFRP (glass fiber reinforced polymer composite) and longer length CFRP (carbon fiber reinforced composite) spar caps. Spar cap cost scales with features such as mass, volume fraction and complexity. Organizational learning is a cost factor. Material and direct labor increase as proportions of total cost while tooling, capital, utilities, and indirect labor decrease. There is good agreement between a manufacturer and the model. Twenty-year turbines were compared with retrofitted spar caps over 25 years for LCOE. Same length GFRP and longer length CFRP spar cap retrofits decrease LCOE. Longer length CFRP spar caps decrease LCOE compared with GFRP retrofits over 25 years. CFRP material cost impacts CFRP retrofit feasibility. Retrofitted turbines must meet engineering, operational performance, and planning requirements criteria. Software algorithms may improve human learning and enable automatic updates from varying design and cost inputs, thereby increasing cost prediction accuracy.
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