scholarly journals In-Situ Observations of Microscale Ductility in a Quasi-Brittle Bulk Scale Epoxy

Polymers ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 2581 ◽  
Author(s):  
Olivier Verschatse ◽  
Lode Daelemans ◽  
Wim Van Paepegem ◽  
Karen De Clerck
Keyword(s):  
Plastic Deformation ◽  
Composite Materials ◽  
Epoxy Resin ◽  
Deformation Behavior ◽  
Fiber Reinforced Composite ◽  
Reinforced Composite ◽  
Reinforcing Fibers ◽  
The Matrix ◽  
Bulk Scale

Fiber reinforced composite materials are typically comprised of two phases, i.e., the reinforcing fibers and a surrounding matrix. At a high volume fraction of reinforcing fibers, the matrix is confined to a microscale region in between the fibers (1–200 µm). Although these regions are interconnected, their behavior is likely dominated by their micro-scale. Nevertheless, the characterization of the matrix material (without reinforcing fibers) is usually performed on macroscopic bulk specimens and little is known about the micro-mechanical behavior of polymer matrix materials. Here, we show that the microscale behavior of an epoxy resin typically used in composite production is clearly different from its macroscale behavior. Microscale polymer specimens were produced by drawing microfibers from vitrifying epoxy resin. After curing, tensile tests were performed on a large set of pure epoxy microfiber specimens with diameters ranging from 30 to 400 µm. An extreme ductility was observed for microscale epoxy specimens, while bulk scale epoxy specimens showed brittle behavior. The microsized epoxy specimens had a plastic deformation behavior resulting in a substantially higher ultimate tensile strength (up to 380 MPa) and strain at break (up to 130 %) compared to their bulk counterpart (68 MPa and 8%). Polarized light microscopy confirmed a rearrangement of the internal epoxy network structure during loading, resulting in the plastic deformation of the microscale epoxy. This was further accompanied by in-situ electron microscopy to further determine the deformation behavior of the micro-specimens during tensile loading and make accurate strain measurements using video-extensometry. This work thus provides novel insights on the epoxy material behavior at the confined microscale as present in fiber reinforced composite materials.

A Study of the Fiber-Matrix Interface in Composite Materials

1992 ◽  
Vol 59 (2S) ◽  
pp. S163-S165 ◽  
Author(s):  
Jin O. Kim ◽  
Haim H. Bau
Keyword(s):  
Composite Materials ◽  
Experimental Technique ◽  
Stress Waves ◽  
Matrix Interface ◽  
Fiber Reinforced ◽  
Fiber Reinforced Composite ◽  
Reinforced Composite ◽  
The Matrix ◽  
Fiber Matrix Interface ◽  
Dispersion And Attenuation

A novel experimental technique for studying the characteristics of the interface between the fibers and the matrix in both undamaged and damaged fiber-reinforced composite materials is described. The experimental technique involves the transmission of stress waves in one or more fibers of the composite. The characteristics of the stress waves, such as speed, dispersion, and attenuation, are measured. These measured variables can be correlated with the characteristics of the bonding between the fiber and the matrix.

scholarly journals Carbon Fiber Polymer Composites

2019 ◽  
Vol 1 (1) ◽  
pp. 276-280
Author(s):  
Lenka Markovičová ◽  
Viera Zatkalíková ◽  
Patrícia Hanusová
Keyword(s):  
Mechanical Properties ◽  
Composite Materials ◽  
Carbon Fiber ◽  
Polymer Composite ◽  
Fiber Orientation ◽  
Environmental Damage ◽  
Fiber Reinforced ◽  
Fiber Reinforced Composite ◽  
Reinforced Composite ◽  
The Matrix

Abstract Carbon fiber reinforced composite materials offer greater rigidity and strength than any other composites, but are much more expensive than e.g. glass fiber reinforced composite materials. Continuous fibers in polyester give the best properties. The fibers carry mechanical loads, the matrix transfers the loads to the fibers, is ductile and tough, protect the fibers from handling and environmental damage. The working temperature and the processing conditions of the composite depend on the matrix material. Polyesters are the most commonly used matrices because they offer good properties at relatively low cost. The strength of the composite increases along with the fiber-matrix ratio and the fiber orientation parallel to the load direction. The longer the fibers, the more effective the load transfer is. Increasing the thickness of the laminate leads to a reduction in the strength of the composite and the modulus of strength, since the likelihood of the presence of defects increases. The aim of this research is to analyze the change in the mechanical properties of the polymer composite. The polymer composite consists of carbon fibers and epoxy resin. The change in compressive strength in the longitudinal and transverse directions of the fiber orientation was evaluated. At the same time, the influence of the wet environment on the change of mechanical properties of the composite was evaluated.

The Effects of Ultrasonic Treatment on Fiber-Reinforced Composite Materials

2009 ◽  
Author(s):  
Chad Braver ◽  
Matthew Tumey ◽  
Adam Harlow ◽  
Qingyou Han
Keyword(s):  
Mechanical Properties ◽  
Composite Materials ◽  
Ultrasonic Treatment ◽  
Void Content ◽  
Fiber Reinforced ◽  
Fiber Reinforced Composite ◽  
Three Point Bending ◽  
Reinforced Composite ◽  
The Matrix ◽  
Reinforcement Fiber

The mechanical properties of fiber-reinforced composite materials are highly dependent on proper saturation of the resin within the reinforcement fibers. The research evaluates the effect of ultrasonic treatment during composite curing, in an effort to increase interlaminar bonding strength, lower void content, and improve the matrices ability to transfer stresses to the reinforcement fiber. The testing methods that were performed evaluated the effects or the ultrasonic treatment on the specimen in three point bending, and shear between layers of the matrix. The mechanical properties and the microstructure of the test specimen are discussed.

Plastic Failure of Fiber-Reinforced Materials

1969 ◽  
Vol 36 (3) ◽  
pp. 542-544 ◽  
Author(s):  
W. Prager
Keyword(s):  
Median Plane ◽  
Fiber Reinforced ◽  
Composite Sheet ◽  
Arbitrary Angle ◽  
Fiber Reinforced Composite ◽  
Reinforced Composite ◽  
Fiber Reinforced Materials ◽  
Simple Tension ◽  
Reinforcing Fibers ◽  
The Matrix

The paper is concerned with failure by plastic flow of the matrix of a fiber-reinforced composite sheet. For unidirectional reinforcement, a completely general state of plane stress in the median plane of the sheet is discussed, but for a two-ply laminate with an arbitrary angle between the two systems of reinforcing fibers only simple tension in any direction to the fibers is investigated.

Investigations into Moisture Diffusion of Fiber Reinforced Composite Materials.

2018 ◽  
Author(s):  
Karla Rosa Reyes ◽  
Karla Rosa Reyes ◽  
Adriana Pavia Sanders ◽  
Lee Taylor Massey ◽  
Corinne Hagan ◽  
...  
Keyword(s):  
Composite Materials ◽  
Moisture Diffusion ◽  
Fiber Reinforced ◽  
Fiber Reinforced Composite ◽  
Reinforced Composite

The effect of nanoparticle additive on surface milling in glass fiber reinforced composite structures

2021 ◽  
pp. 096739112110141
Author(s):  
Ferhat Ceritbinmez ◽  
Ahmet Yapici ◽  
Erdoğan Kanca
Keyword(s):  
Composite Materials ◽  
Glass Fiber ◽  
Composite Structures ◽  
Fiber Composite ◽  
Cutting Speed ◽  
Fiber Reinforced ◽  
Fiber Reinforced Composite ◽  
Reinforced Composite ◽  
Glass Fiber Reinforced ◽  
Composite Layers

In this study, the effect of adding nanosize additive to glass fiber reinforced composite plates on mechanical properties and surface milling was investigated. In the light of the investigations, with the addition of MWCNTs additive in the composite production, the strength of the material has been changed and the more durable composite materials have been obtained. Slots were opened with different cutting speed and feed rate parameters to the composite layers. Surface roughness of the composite layers and slot size were examined and also abrasions of cutting tools used in cutting process were determined. It was observed that the addition of nanoparticles to the laminated glass fiber composite materials played an effective role in the strength of the material and caused cutting tool wear.

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