scholarly journals On-Demand Photopolymerization of Fiber-Reinforced Polymers Exhibiting the Shape Memory Effect

Polymers ◽  
2021 ◽  
Vol 13 (24) ◽  
pp. 4300
Author(s):  
Xavier Allonas ◽  
Johann Pierrel ◽  
Ahmad Ibrahim ◽  
Céline Croutxé-Barghorn
Keyword(s):  
Shape Memory ◽  
Shape Memory Effect ◽  
Memory Effect ◽  
Glass Fibers ◽  
Polymer Chains ◽  
Fiber Reinforced Polymers ◽  
Secondary Amines ◽  
Fiber Reinforced ◽  
One Pot ◽  
Reinforced Polymers

Fiber-reinforced polymers exhibiting the shape memory effect were created on the basis of a one-pot three-step chemical process. The first step is a Michael addition, which creates linear polymer chains. The second step is free radical photopolymerization, which increases the degree of curing of polymers. The last step is post-consolidation due to the reaction of previously formed secondary amines on the residual double bonds. By employing such chemistry to impregnate glass fibers, the final composite exhibits a convincing shape memory effect, as shown by cyclic thermomechanical tests.

scholarly journals Aplicação da análise hierárquica como ferramenta de tomada de decisão para escolha do compósito de reforço com polímeros reforçados com fibras

2013 ◽  
Vol 3 (3) ◽  
pp. 161-176
Author(s):  
D. H. Perelles ◽  
M. F. Medeiros ◽  
M. R. Garcez
Keyword(s):  
Decision Making ◽  
Glass Fibers ◽  
Fiber Reinforced Polymers ◽  
Fiber Reinforced ◽  
Analytic Hierarchy ◽  
Reinforced Polymers ◽  
Structural Reinforcement ◽  
De Se ◽  
Hierarchy Process ◽  
Decision Making Tool

RESUMOO reforço de estruturas com Polímeros Reforçados com Fibras (PRF) é uma alternativa que tem sido muito utilizada em intervenções executadas em elementos de concreto armado. A fibra de carbono é a mais empregada na formação dos compósitos de reforço utilizados em obras civis. Existe, no entanto, a possibilidade de se ampliar as opções de fibras formadoras do compósito utilizando as fibras de aramida e de vidro. Como uma ferramenta alternativa de tomada de decisão, o Método de Análise Hierárquica, baseado em critérios analisados de forma qualitativa e quantitativa, será utilizado neste trabalho para a avaliação das fibras de carbono, aramida e vidro, de forma a se obter qual material seria o mais apropriado para a execução de um reforço estrutural considerando como principais parâmetros de análise os custos dos materiais e as tensões e as deformações que os elementos poderão apresentar. A aplicação desta técnica de interpretação de resultados se mostrou muito útil, podendo ser considerada adequada para estudos que exijam uma tomada de decisão entre diferentes sistemas de reforço com PRF.Palabras clave: Reforço estrutural; polímeros reforçados com fibras; carbono; aramida; vidro; método da análise hierárquica.ABSTRACTStrengthening structures with Fiber Reinforced Polymers (FRP) is an alternative that has been used in interventions performed on reinforced concrete elements. Carbon fibers are the most used in the formation of composite reinforcement used in civil works. There is, however, possible to expand the options of forming fibers using the composite fibers of aramid and glass. As an alternative decision-making tool, the Analytic Hierarchy Process, based on criteria analyzed qualitatively and quantitatively, will be used in this work for the evaluation of carbon, aramid and glass fibers in order to obtain what material would be more suitable for the implementation of a structural reinforcement considering how key parameters of analysis material costs and the tensions and strains that may exhibit elements. This decision-making tool showed useful and can be considered suitable to select different FRP systems.Keywords: Structural strengthening; fiber-reinforced polymers; carbon; aramid; glass; hierarchical analysis method.

Active Vortex Generator Deployed on Demand by Active Hybrid Composites From Shape Memory Alloys and Fiber Reinforced Polymers

2017 ◽  
Author(s):  
Martin Gurka ◽  
Sebastian Nissle ◽  
Moritz Hübler ◽  
Max Kaiser
Keyword(s):  
Shape Memory Alloys ◽  
Shape Memory ◽  
Flow Separation ◽  
Hybrid Composites ◽  
Vortex Generators ◽  
Fiber Reinforced Polymers ◽  
Fe Model ◽  
Fiber Reinforced ◽  
Reinforced Polymers ◽  
On Demand

High performance airfoils with laminar airflow exhibit minimum drag and maximum lift, but tend to sudden stall due to flow separation at low air speed. This requires an increased approach speed of the aircraft, resulting in less steep approaches and a higher noise exposure of the surroundings. New active vortex generators, deployed only on demand at low speed, energizing the boundary layer of air flow and reducing flow separation, can help to overcome this critical situation. Active hybrid composites, combining the actuation capability of shape memory alloys (SMA) with the possibility of tailoring the compliance of fiber reinforced polymers (FRP) on the materials level, provide an active aerodynamic system with high lightweight potential and small space requirements. Being one of the first applications of active hybrid structures from SMA and FRP we will demonstrate the potential of this new technology with an integrated system of active vortex generators for a glider. In this contribution we present - the design process, based on a FE-model and careful characterization of the actuating SMA and the composite material - manufacturing relevant aspects for reliable series production - the testing of single vortex generators in lab scale under aerodynamic load - and an overview of the whole system.

scholarly journals Additive Re-Manufacturing of Mechanically Recycled End-of-Life Glass Fiber-Reinforced Polymers for Value-Added Circular Design

Materials ◽  
2020 ◽  
Vol 13 (16) ◽  
pp. 3545
Author(s):  
Alessia Romani ◽  
Andrea Mantelli ◽  
Raffaella Suriano ◽  
Marinella Levi ◽  
Stefano Turri
Keyword(s):  
Additive Manufacturing ◽  
Glass Fiber ◽  
End Of Life ◽  
Glass Fibers ◽  
Fiber Reinforced Polymers ◽  
Fiber Reinforced ◽  
Reinforced Polymers ◽  
Glass Fiber Reinforced Polymers ◽  
Glass Fiber Reinforced ◽  
Circular Design

Despite the large use of composites for industrial applications, their end-of-life management is still an open issue for manufacturing, especially in the wind energy sector. Additive manufacturing technology has been emerging as a solution, enhancing circular economy models, and using recycled composites for glass fiber-reinforced polymers is spreading as a new additive manufacturing trend. Nevertheless, their mechanical properties are still not comparable to pristine materials. The purpose of this paper is to examine the additive re-manufacturing of end-of-life glass fiber composites with mechanical performances that are comparable to virgin glass fiber-reinforced materials. Through a systematic characterization of the recyclate, requirements of the filler for the liquid deposition modeling process were identified. Printability and material surface quality of different formulations were analyzed using a low-cost modified 3D printer. Two hypothetical design concepts were also manufactured to validate the field of application. Furthermore, an understanding of the mechanical behavior was accomplished by means of tensile tests, and the results were compared with a benchmark formulation with virgin glass fibers. Mechanically recycled glass fibers show the capability to substitute pristine fillers, unlocking their use for new fields of application.

scholarly journals A Study of the Dry Linear Contact Between Glass Fiber-reinforced Composite Materials and Steel

2019 ◽  
Vol 56 (3) ◽  
pp. 616-620
Author(s):  
Virgil Florescu ◽  
Dorin Rus ◽  
Laurentiu Rece
Keyword(s):  
Glass Fiber ◽  
Glass Fibers ◽  
Fiber Reinforced Polymers ◽  
Wear Behaviour ◽  
Wear Volume ◽  
Wear Depth ◽  
Fiber Reinforced ◽  
Reinforced Polymers ◽  
Wear Process ◽  
Glass Fiber Reinforced

The thermoplastic materials studied are biphasic. They consist of a polymer mass and a short glass fiber, the percentage being between 10 and 30%. We have shown, both analytically and graphically, the evolution of wear occurring on the steel surface in contact with glass fiber-reinforced polymers. The evolution in time of this process depends on the evolution of the friction coefficient in the process of the dry linear contact between different polymers and different types of steels. We have made a connection between the theoretical case and the experimental results. The experimental method used was the wear imprint method through which the wear depth and wear volume were determined. The wear process is complex and is accompanied by adhesion and corrosion phenomena. Any modification of the input parameters such as speed, temperature, load, quantity of glass fibers in the polymer lead at a certain one evolution of the wear behaviour of the composite material.

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