scholarly journals Comparison and Impact of Different Fiber Debond Techniques on Fiber Reinforced Flexible Composites

Polymers ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 472 ◽  
Author(s):  
Julia Beter ◽  
Bernd Schrittesser ◽  
Boris Maroh ◽  
Essi Sarlin ◽  
Peter Filipp Fuchs ◽  
...  
Keyword(s):  
Single Fiber ◽  
Fiber Bundles ◽  
Testing Device ◽  
Adhesion Properties ◽  
Test Setup ◽  
Flexible Composites ◽  
Pull Out ◽  
Specimen Holder ◽  
Microbond Test ◽  
Modified Test

The focus of this paper is the realization and verification of a modified fiber bundle pull-out test setup to estimate the adhesion properties between threads and elastic matrix materials with a more realistic failure mode than single fiber debond techniques. This testing device including a modified specimen holder provides the basis for an adequate estimation of the interlaminar adhesion of fiber bundles including the opportunity of a faster, easier, and more economic handling compared to single fiber tests. The verification was done with the single-fiber and microbond test. Overall, the modified test setup showed the typical pull-out behavior, and the relative comparability between different test scales is given.

scholarly journals Fem Analysis and Comparison of Single Fiber Pull-Out Tests

1997 ◽  
Vol 6 (4) ◽  
pp. 096369359700600 ◽  
Author(s):  
S. Feih ◽  
P. Schwartz
Keyword(s):  
Shear Stress ◽  
Stress Distribution ◽  
Fem Analysis ◽  
Shear Stress Distribution ◽  
Single Fiber ◽  
Stress Distributions ◽  
Fiber Coating ◽  
Uniform Shear ◽  
Pull Out ◽  
Microbond Test

This work analyses the stress distributions during the pull-out test and the microbond test by FEA. Both tests are found to lead to the same results. The simulation result predicts the in praxis calculated IFSS value. Fiber coating leads to a more uniform shear stress distribution.

scholarly journals Surface Treatment of Carbon Fibers by Oxy-Fluorination

Materials ◽  
2019 ◽  
Vol 12 (4) ◽  
pp. 565 ◽  
Author(s):  
Iris Kruppke ◽  
Christina Scheffler ◽  
Frank Simon ◽  
Rolf-Dieter Hund ◽  
Chokri Cherif
Keyword(s):  
Carbon Fibers ◽  
Photoelectron Spectroscopy ◽  
Surface Composition ◽  
Fluorine Content ◽  
Single Fiber ◽  
Fluorine Concentration ◽  
Adhesion Properties ◽  
Pull Out ◽  
Treated Carbon ◽  
A Minor

In this paper, the oxy-fluorination process and the influence of different concentrations of fluorine and oxygen in the gas phase on the physicochemical properties of polyacrylonitrile(PAN)-based carbon fibers are described. The properties of the treated carbon structures are determined by zeta potential and tensiometry measurements. In addition, changes in surface composition and morphology are investigated by X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM). Adhesion properties are characterized by the single fiber pull-out (SFPO) test. Furthermore, changes in intrinsic properties are described by means of tensile and density measurements. After a primary desizing effect by oxy-fluorination, an increased number of oxygen-containing surface functional groups could be detected, which led to more debonding work in SFPOs with an epoxy-based matrix. It was also shown that the polar surface energy grows with rising fluorine concentration in the reaction gas mixture. In addition, a minor increase of ~10% in the maximum strength of PAN-based carbon fibers is detected by single fiber tensile measurements after oxy-fluorination with a fluorine content of 5% in the reaction mixture.

scholarly journals Dynamic Single-Fiber Pull-Out of Polypropylene Fibers Produced with Different Mechanical and Surface Properties for Concrete Reinforcement

Materials ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 722
Author(s):  
Enrico Wölfel ◽  
Harald Brünig ◽  
Iurie Curosu ◽  
Viktor Mechtcherine ◽  
Christina Scheffler
Keyword(s):  
Tensile Strength ◽  
Dynamic Loading ◽  
Melt Spinning ◽  
Structural Changes ◽  
High Surface ◽  
Single Fiber ◽  
Scanning Calorimetry ◽  
Matrix Interaction ◽  
Pull Out ◽  
Fiber Matrix

In strain-hardening cement-based composites (SHCC), polypropylene (PP) fibers are often used to provide ductility through micro crack-bridging, in particular when subjected to high loading rates. For the purposeful material design of SHCC, fundamental research is required to understand the failure mechanisms depending on the mechanical properties of the fibers and the fiber–matrix interaction. Hence, PP fibers with diameters between 10 and 30 µm, differing tensile strength levels and Young’s moduli, but also circular and trilobal cross-sections were produced using melt-spinning equipment. The structural changes induced by the drawing parameters during the spinning process and surface modification by sizing were assessed in single-fiber tensile experiments and differential scanning calorimetry (DSC) of the fiber material. Scanning electron microscopy (SEM), atomic force microscopy (AFM) and contact angle measurements were applied to determine the topographical and wetting properties of the fiber surface. The fiber–matrix interaction under quasi-static and dynamic loading was studied in single-fiber pull-out experiments (SFPO). The main findings of microscale characterization showed that increased fiber tensile strength in combination with enhanced mechanical interlocking caused by high surface roughness led to improved energy absorption under dynamic loading. Further enhancement could be observed in the change from a circular to a trilobal fiber cross-section.

Effect of Sisal Fiber Surface Treatments on Sisal Fiber Reinforced Polypropylene (PP) Composites

2014 ◽  
Vol 906 ◽  
pp. 167-177 ◽  
Author(s):  
Hou Lei Gan ◽  
Lei Tian ◽  
Chang Hai Yi
Keyword(s):  
Surface Morphology ◽  
Morphological Changes ◽  
Fiber Surface ◽  
Atmospheric Plasma ◽  
Single Fiber ◽  
Sisal Fiber ◽  
Fiber Reinforced ◽  
Polypropylene Composites ◽  
Pull Out ◽  
Debonding Process

Abstract: The Interface of sisal fiber which was treated by using alkali, potassium permanganate, atmospheric plasma and silane reinforced polypropylene composites were investigated by single fiber pull-out testes and surface morphology were studied. The results indicated that the morphological changes observed on the sisal fiber surface were obviously evident. Untreated, permanganate and plasma treated sisal fiber reinforced PP show a stable debonding process. Silane treated sisal fiber reinforced PP show an unstable debonding process. Single fiber pull-out tests indicated that the IFSS value was in the order of FIB < FIBKMnO4 < FIBP < FIBKH-550 < FIBKH-570. As can be seen from surface morphology of pull-out fiber, a little of PP resin was adhered to the pull-out FIB, FIBKMnO4, FIBP of sisal fiber. In contrast, PP resin at the surface of pull-out fiber was flaked off and sisal fibril was drawn out from sisal fiber were observed from pull-out fibers of FIBKH-550 and FIBKH-570.

scholarly journals The Effect of Ti-6Al-4V Alloy Surface Structure on the Adhesion and Morphology of Unidirectional Freeze-Coated Gelatin

Coatings ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 434
Author(s):  
Snehashis Pal ◽  
Zdenka Peršin ◽  
Tomaž Vuherer ◽  
Igor Drstvenšek ◽  
Vanja Kokol
Keyword(s):  
Bone Ingrowth ◽  
Dip Coating ◽  
Freezing Process ◽  
Implant Surface ◽  
Adhesion Properties ◽  
Wetting Properties ◽  
Pull Out ◽  
Biomimetic Coating ◽  
Substrate Surfaces ◽  
Surrounding Bone

The modification of a metal implant surface with a biomimetic coating of bone-like anisotropic and graded porosity structures to improve its biological anchorage with the surrounding bone tissue at implanting, is still a high challenge. In this paper, we present an innovative way of a gelatin (GEL) dip-coating on Ti-6Al-4V substrates of different square-net surface textures by the unidirectional deep-freezing process at simultaneous cross-linking using carbodiimide chemistry. Different concentrations of GEL solution were used to study the changes in morphology, density, and mechanical properties of the coatings. In addition, the surface free energy and polarity of Ti-6Al-4V substrate surfaces and GEL solutions have been evaluated to assess the wetting properties at the substrate interfaces, and to describe the adhesion of GEL macromolecules with their surfaces, being supported by mechanical pull-out testing. The results indicate that the coating’s morphology depends primarily on the Ti-6Al-4V substrate’s surface texture and second, on the concentration of GEL, which further influences their adhesion properties, orientation, morphological arrangement, as well as compression strength. The substrate with a 300 × 300 μm2 texture resulted in a highly adhered GEL coating with ≥80% porosity, interconnected and well-aligned pores of 75–200 μm, required to stimulate the bone ingrowth, mechanically and histologically.

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