scholarly journals Quasi-Static Tests of Hybrid Adhesive Bonds Based on Biological Reinforcement in the Form of Eggshell Microparticles

Polymers ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 1391 ◽  
Author(s):  
Viktor Kolář ◽  
Miroslav Müller ◽  
Rajesh Mishra ◽  
Anna Rudawska ◽  
Vladimír Šleger ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Cyclic Loading ◽  
Service Life ◽  
Adhesive Layer ◽  
Maximum Load ◽  
Adhesive Bonds ◽  
Static Tests ◽  
Static Test ◽  
The Matrix ◽  
Positive Effect

The paper is focused on the research of the cyclic loading of hybrid adhesive bonds based on eggshell microparticles in polymer composite. The aim of the research was to characterize the behavior of hybrid adhesive bonds with composite adhesive layer in quasi-static tests. An epoxy resin was used as the matrix and microparticles of eggshells were used as the filler. The adhesive bonds were exposed to cyclic loading and their service life and mechanical properties were evaluated. Testing was performed by 1000 cycles at 5–30% (165–989 N) and 5–70% (165–2307 N) of the maximum load of the filler-free bond in the static test. The results of the research show the importance of cyclic loading on the service life and mechanical properties of adhesive bonds. Quasi-static tests demonstrated significant differences between measured intervals of cyclic loading. All adhesive bonds resisted 1000 cycles of the quasi-static test with an interval loading 5–30%. The number of completed quasi-static tests with the interval loading 5–70% was significantly lower. The filler positively influenced the service life of adhesive bonds at a higher amount of quasi-static tests, i.e., the safety of adhesive bonds increased. The filler had a positive effect on adhesive bonds ABF2, where the strength significantly increased up to 20.26% at the loading of 5–30% against adhesive bonds ABF0. A viscoelasticity characteristic (creep) of the adhesive layer occurred at higher values of loading, i.e., between loading 5–70%. The viscoelasticity behavior did not occur at lower values of loading, i.e., between loading 5–30%.

scholarly journals Quasi-Static Shear Test of Hybrid Adhesive Bonds Based on Treated Cotton-Epoxy Resin Layer

Polymers ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 2945
Author(s):  
Martin Tichý ◽  
Viktor Kolář ◽  
Miroslav Müller ◽  
Rajesh Kumar Mishra ◽  
Vladimír Šleger ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Strain Difference ◽  
Cyclic Stress ◽  
Cotton Fabrics ◽  
Adhesive Bonds ◽  
Static Tests ◽  
Static Test ◽  
Static Conditions ◽  
Pure Resin

This research evaluates the mechanical properties of hybrid adhesive bonds with various 100% cotton fabrics in static and quasi-static conditions and the influence of alkali surface treatment (NaOH) of the cotton fabrics on the mechanical properties. Biological fibers in polymers are characterized by low wettability with the matrix, which decreases mechanical properties. Adhesive bonds usually operate in cyclic stress, which causes irreversible failure before maximal strength. In this paper, a quasi-static test was used to load the adhesive bonds in 5–50% (192–1951 N) and 5–70% (192–2732 N) intervals with 1000 cycles. The results of SEM analysis showed good wettability of alkali treated cotton fabric with NaOH solution in hybrid adhesive bonds. The static test proved the influence of reinforcing cotton fabrics on shear tensile strength against pure resin, i.e., sample Erik up to 19% on 14.90 ± 1.15 MPa and sample Tera up to 21% on 15.28 ± 1.05 MPa. The adhesive bonds with pure resin did not resist either quasi-static tests. Reinforcing cotton fabrics resisted both quasi-static tests, even shear tensile strength increases up to 10% on 16.34 ± 1.24 MPa for the fabric Erik. The results of strain difference of adhesive bonds with Tera and Erik confirmed that a lower value of the difference during cyclic loading positively influenced the ultimate shear tensile strength.

scholarly journals Experimental Investigation of Wavy-Lap Bonds with Natural Cotton Fabric Reinforcement under Cyclic Loading

Polymers ◽  
2021 ◽  
Vol 13 (17) ◽  
pp. 2872
Author(s):  
Viktor Kolář ◽  
Miroslav Müller ◽  
Martin Tichý ◽  
Rajesh Kumar Mishra ◽  
Petr Hrabě ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Cyclic Loading ◽  
Cotton Fabric ◽  
Mechanical Performance ◽  
Matrix Material ◽  
Safety Evaluation ◽  
Positive Influence ◽  
Sem Analysis ◽  
Adhesive Bonds ◽  
Fabric Surface

This study is focused on the mechanical properties and service life (safety) evaluation of hybrid adhesive bonds with shaped overlapping geometry (wavy-lap) and 100% natural cotton fabric used as reinforcement under cyclic loading using various intensities. Cyclic loading were implemented between 5–50% (267–2674 N) and 5–70% (267–3743 N) from the maximum strength (5347 N) measured by static tensile test. The adhesive bonds were loaded by 1000 cycles. The test results demonstrated a positive influence of the used reinforcement on the mechanical properties, especially during the cyclic loading. The adhesive bonds Tera-Flat withstood the cyclic load intensity from 5–70% (267–3743 N). The shaped overlapping geometry (wavy-lap bond) did not have any positive influence on the mechanical performance, and only the composite adhesive bonds Erik-WH1 and Tera-WH1 withstood the complete 1000 cycles with cyclic loading values between 5–50% (267–2674 N). The SEM analysis results demonstrated a positive influence on the fabric surface by treatment with 10% NaOH aqueous solution. The unwanted compounds (lignin) were removed. Furthermore, a good wettability has been demonstrated by the bonded matrix material. The SEM analysis also demonstrated micro-cracks formation, with subsequent delamination of the matrix/reinforcement interface caused by cyclic loading. The experimental research was conducted for the analysis of hybrid adhesive bonds using curved/wavy overlapping during both static and cyclic loading.

Effect of Temperature on the Properties of the Rolled Composites Based on Polyethylene and Rubber Particles

INEOS OPEN ◽  
2020 ◽  
Vol 3 ◽  
pp. 182-187
Author(s):  
O. A. Serenko ◽  
◽  
A. V. Efimov ◽  
Keyword(s):  
Mechanical Properties ◽  
Crack Resistance ◽  
Temperature Rise ◽  
Elevated Temperatures ◽  
Effect Of Temperature ◽  
Rubber Content ◽  
Stress Strain ◽  
Rubber Particles ◽  
The Matrix ◽  
Positive Effect

The stress–strain properties of the isotropic and rolled composites based on polyethylene (PE) and rubber particles are studied. The mechanical properties are determined at 20, 50, and 70 °С. It is shown that one of the factors ensuring the maintenance of plasticity of the filled rolled PE is an increase in the crack resistance of the matrix, which is manifested in the changes of the forms of defects that arise during tension. At the rubber content no more than 20 wt %, a temperature rise leads to a change in the mechanism of the composite fracture from brittle to ductile. It is shown that the positive effect of rolling of the rubber plastics is retained during their testing at elevated temperatures.

scholarly journals Effects of Silica Nanoparticle Addition on Physical and Mechanical properties of Sugar Palm Fibers Reinforced Cement Composite Concrete

2020 ◽  
Vol 1 (1) ◽  
pp. 24
Author(s):  
Bintoro Siswo Nugroho ◽  
Yoga Pebrianto ◽  
Irfana Diah Faryuni ◽  
Asifa Asri
Keyword(s):  
Mechanical Properties ◽  
Physical And Mechanical Properties ◽  
Silica Nanoparticle ◽  
Cement Composite ◽  
Nano Silica ◽  
Water Testing ◽  
The Matrix ◽  
Reinforced Cement ◽  
Positive Effect

This study examines the effect of nanosilica addition to the physical and mechanical properties of sugar palm fibers (SPFs) reinforced cement composite concrete. The composite concrete ingredients are SPFs as the filler, cement and nano-silica as the matrix, CaCl2 as the catalyst, and water. Testing and fabrication of the composite concrete were performed according to the standard of ASTM C 1185 and ASTM C 1186. The results obtained show that, in general, the addition of nanosilica improves the quality of the composite concrete. A positive effect is attained by adding nanosilica to its optimum amount. The excessive addition of nanosilica reduces the quality of the composite. The composite's mechanical property that is negatively affected by the addition of the nanosilica is the elasticity, in which more nanosilica added stiffer the composite.

Study of the pull-out test of multifilament yarns embedded in cementitious matrix

2020 ◽  
Vol 55 (2) ◽  
pp. 169-185
Author(s):  
Anne-Claire Slama ◽  
Jean-Louis Gallias ◽  
Bruno Fiorio
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Cement Composite ◽  
Maximum Load ◽  
Variable Number ◽  
Tensile Behaviour ◽  
Cementitious Matrix ◽  
Pull Out ◽  
The Matrix ◽  
Multifilament Yarns

In order to understand the impregnation mechanism of a yarn by a cementitious matrix and its influence on the mechanical properties of a yarn/cement composite, pull-out tests have been performed on samples of yarn/cement. Two embedded lengths for the yarn and different rheological and mechanical properties for the matrix were tested. Two pull-out modes were distinguished according to the compressive strength of matrices. For matrices with a compressive strength between 60 and 70 MPa the pull-out mode is characterized by a behaviour close to the tensile behaviour of the yarn, with maximum load values reaching approximately 60% of the tensile maximum load because of filaments damages. For matrices with compressive strength inferior to 60 MPa, the pull-out mode exhibits a residual phase linked to a slippage and an extraction of a variable number of filaments, with lower maximum load values than the first pull-out mode. After pull-out test, for some samples with filaments extraction, an innovative method based on a double impregnation with resin enables to visualize the yarn/matrix interface and identify the level of impregnation of the filaments by using confocal microscopy. It is concluded that this level of impregnation has a direct influence on the mechanical behaviour of the embedded yarn, except for the slippage and extraction phase, but the rheological properties of the matrix has no significant influence on this impregnation.

scholarly journals Effect of Potassium Phosphate Content in Aluminosilicate Matrix on Mechanical Properties of Carbon Prepreg Composites

Materials ◽  
2021 ◽  
Vol 15 (1) ◽  
pp. 61
Author(s):  
Eliška Kohoutová ◽  
Pavlína Hájková ◽  
Jan Kohout ◽  
Aleš Soukup
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Potassium Phosphate ◽  
Composite Plates ◽  
Phosphate Content ◽  
Layer Composite ◽  
Weave Fabric ◽  
The Matrix ◽  
Positive Effect ◽  
Alkali Activated

Six matrices based on alkali-activated aluminosilicate with different amounts of potassium phosphate were prepared for the production of six-layer composite plates. The addition of potassium phosphate in the matrix was 2 wt%, 4 wt%, 6 wt%, 8 wt% and 10 wt% of its total weight. The matrix without the potassium phosphate was also prepared. The aim of this study was to determine whether this addition has an effect on the tensile strength or Young’s modulus of composites at temperatures up to 800 °C. Changes in the thickness and weight of the samples after this temperature were also monitored. Carbon plain weave fabric was chosen for the preparation of the composites. The results show that under normal conditions, the addition of potassium phosphate has no significant effect on the mechanical properties; the highest measured tensile strengths were around 350 MPa. However, at temperatures of 600 °C and 800 °C the addition of potassium phosphate had a positive effect, with the tensile strength of the composites being up to 300% higher than the composites without the addition. The highest measured values of composites after one hour at 600 °C were higher than 100 MPa and after 1 h at 800 °C higher than 85 MPa.

Effects of Rare-Earth Oxides Doping on Microstructures and Properties of Al2O3/TiAl Composites

2011 ◽  
Vol 675-677 ◽  
pp. 143-146
Author(s):  
Fen Wang ◽  
Xiao Feng Wang ◽  
Jian Feng Zhu ◽  
Liu Yi Xiang
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Rare Earth ◽  
Flexural Strength ◽  
Rare Earth Oxide ◽  
Rare Earth Oxides ◽  
Oxide Content ◽  
The Matrix ◽  
Al2o3 Particles ◽  
Positive Effect

Effects of rare-earth oxides addition (0.38~1.52 mol% of Sm2O3, Eu2O3 and Er2O3) on the property and microstructure of the hot-pressed (1300°C, 2h, 35 MPa) Al2O3 (12 wt %)/TiAl insitu composites have been investigated. The results show that the doping of rare-earth oxides has a positive effect on both mechanical properties and densities of Al2O3/TiAl composites. Densities enhanced with increasing of rare-earth oxides. The flexural strength and fracture toughness were higher than other samples when the rare-earth oxide content was 0.38 mol %. The matrix grains and Al2O3 particles were significantly refined, and Al2O3 particles evenly distributed in the matrix.

Application of High Frequency Dielectric Spectroscopy for the Assessment of Durability of Adhesively Bonded Composite Structures

1999 ◽  
Author(s):  
P. Boinard ◽  
R. A. Pethrick ◽  
W. M. Banks
Keyword(s):  
Mechanical Properties ◽  
Carbon Fibre ◽  
High Frequency ◽  
Composite Structures ◽  
Adhesive Layer ◽  
Dielectric Study ◽  
Adhesively Bonded ◽  
Wide Range ◽  
The Matrix ◽  
Bonded Composite

Abstract Composites materials, especially adhesively bonded structures are being used in a wide range of applications, including situations where they become exposed to high levels of moisture. Ingress of moisture into a polymeric material will in general lead to changes in its mechanical properties usually associated with plasticisation effects. In bonded composite structures, water ingress can influence not only the mechanical properties of the matrix but also those of the matrix-fibre and adhesive-adherent interfaces. Over the last ten years, the application of high-frequency dielectric techniques to the characterisation of the integrity and durability of adhesively bonded metallic structures has been extensively investigated by the coauthors. In general, a bonded structure resembles a wave-guide in which the adhesive layer is the dielectric. Changes in the characteristics as a function of time of exposure to the environment can be used to monitor the ageing of such structures. This paper discusses the application of the principles to the study of carbon fibre reinforced plastics (CFRP) adhesively bonded composite structures. Carbon fibre is in general less conductive than aluminium material. However, it is sufficiently conductive to sustain the propagation of high-frequency dielectric signals. The effect of changes in the surface alignment and subsequent bulk orientation of carbon fibres on the dielectric propagation has been investigated. The ingress of moisture in the raw materials and in the joint structure is presented. The high-frequency time domain response (TDR) analysis allows the integrity of the structure to be explored and a good correlation is shown between TDR analysis and gravimetric results. This study indicates that the success obtained in the application of high frequency dielectric measurements to adhesively bonded aluminium structures is also applicable to CFRP bonded structures. The dielectric study not only indicates a new way to assess the state of such a structure but is also producing new insights into the application of TDR measurement to non-isotropic materials.

Structural features and strength behavior of TRIP/TWIP steels

2020 ◽  
pp. 5-18
Author(s):  
D. V. Prosvirnin ◽  
◽  
M. S. Larionov ◽  
S. V. Pivovarchik ◽  
A. G. Kolmakov ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Chemical Composition ◽  
Thermomechanical Processing ◽  
Maximum Load ◽  
Structural Features ◽  
Stacking Fault ◽  
Stacking Fault Energy ◽  
Structural And Functional Properties ◽  
Twip Steels ◽  
The Creation

A review of the literature data on the structural features of TRIP / TWIP steels, their relationship with mechanical properties and the relationship of strength parameters under static and cyclic loading was carried out. It is shown that the level of mechanical properties of such steels is determined by the chemical composition and processing technology (thermal and thermomechanical processing, hot and cold pressure treatment), aimed at achieving a favorable phase composition. At the atomic level, the most important factor is stacking fault energy, the level of which will be decisive in the formation of austenite twins and / or the formation of strain martensite. By selecting the chemical composition, it is possible to set the stacking fault energy corresponding to the necessary mechanical characteristics. In the case of cyclic loads, an important role is played by the strain rate and the maximum load during testing. So at high loading rates and a load approaching the yield strength under tension, the intensity of the twinning processes and the formation of martensite increases. It is shown that one of the relevant ways to further increase of the structural and functional properties of TRIP and TWIP steels is the creation of composite materials on their basis. At present, surface modification and coating, especially by ion-vacuum methods, can be considered the most promising direction for the creation of such composites.

Morphology and Mechanical Properties of Polyethylene Terephthalate/Ethylene Propylene Diene Monomer (PET/EPDM) in the Presence of Nanoclay

2020 ◽  
Vol 57 (3) ◽  
pp. 249-259
Author(s):  
Baifen Liu ◽  
Mohammad Mirjalili ◽  
Peiman Valipour ◽  
Sajad Porzal ◽  
shirin Nourbakhsh
Keyword(s):  
Mechanical Properties ◽  
Impact Strength ◽  
Thermal Destruction ◽  
Processing Temperature ◽  
Tem Analysis ◽  
Maximum Stiffness ◽  
Cloisite 30B ◽  
Nano Clay ◽  
The Matrix ◽  
Sample Maximum

This research deals with the mechanical properties, microstructure, and interrelations of triple nanocomposite based on PET/EPDM/Nanoclay. These properties were examined in different percentages of PET/EPDM blend with compatibilizer (Styrene-Ethylene/Butylene-Styrene)-G-(Maleic anhydrate) (SEBS-g-MAH). Results showed that the addition of 15% SEBS-g-MAH improved the toughness and impact strength of this nanocomposite. SEM micrographs indicated the most stable fuzzy microstructure in a 50/50 mixture of scattered phases of EPDM/SEBS-g-MAH. The effects of percentages of 1, 3, 5, 7 nanoclay Cloisite 30B (C30B) on the improvement of the properties were evaluated. With the addition of nano clay, the toughness and impact strength was reduced. Thermal destruction of nanoclay in processing temperature led to the decreasing dispersion of clay plates in the matrix and a reduction in the distances of nano clay plates in the composite compared to pure nano clay. XRD and TEM analysis was used to demonstrate the results. By adding 1% of nanoclay to the optimal sample, maximum stiffness, and Impact strength, among other nanocomposites, was achieved.

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