Determination of the Mechanical Properties of Composite Materials by Tensile Tests. Part II: Strength Properties

The aim of this work is to compare from an experimental point of view the determination of in-plane shear strength of unidirectional composite materials by means of two off-axis tests: three-point flexure and tensile. In the case of the off-axis three-point flexure test, the condition of small displacements and the condition of lift-off between the specimen and the fixture supports have been taken into account. Some considerations regarding stress and displacement fields are presented. The in-plane shear characterization has been performed on a carbon fiber reinforced unidirectional laminate with several fiber orientation angles: 10°, 20°, 30°, and 45°. Test conditions for both off-axis experimental methods, in order to ensure their applicability, are presented. Off-axis flexure test is considered more suitable than off-axis tensile test for the determination of in-plane shear strength.

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Development of green nanocomposites reinforced by cellulose nanofibers extracted from paper sludge

Modern Physics Letters B ◽

10.1142/s0217984915400254 ◽

2015 ◽

Vol 29 (06n07) ◽

pp. 1540025 ◽

Cited By ~ 1

Author(s):

Hitoshi Takagi ◽

Antonio N. Nakagaito ◽

Kazuya Kusaka ◽

Yuya Muneta

Keyword(s):

Mechanical Properties ◽

Composite Materials ◽

Mechanical Treatment ◽

Raw Materials ◽

Cellulose Nanofibers ◽

Tensile Tests ◽

Cellulose Nanofiber ◽

Paper Sludge ◽

Reinforcing Effect ◽

Mechanical And Physical Properties

Cellulose nanofibers have been showing much greater potential to enhance the mechanical and physical properties of polymer-based composite materials. The purpose of this study is to extract the cellulose nanofibers from waste bio-resources; such as waste newspaper and paper sludge. The cellulosic raw materials were treated chemically and physically in order to extract individualized cellulose nanofiber. The combination of acid hydrolysis and following mechanical treatment resulted in the extraction of cellulose nanofibers having diameter of about 40 nm. In order to examine the reinforcing effect of the extracted cellulose nanofibers, fully biodegradable green nanocomposites were fabricated by composing polyvinyl alcohol (PVA) resin with the extracted cellulose nanofibers, and then the tensile tests were conducted. The results showed that the enhancement in mechanical properties was successfully obtained in the cellulose nanofiber/PVA green nanocomposites.

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50CrMo4 Steel-Determination of Mechanical Properties at Lowered and Elevated Temperatures, Creep Behavior, and Fracture Toughness Calculation

Journal of Engineering Materials and Technology ◽

10.1115/1.4000669 ◽

2010 ◽

Vol 132 (2) ◽

Cited By ~ 12

Author(s):

J. Brnic ◽

M. Canadija ◽

G. Turkalj ◽

D. Lanc

Keyword(s):

Mechanical Properties ◽

Elevated Temperatures ◽

Tensile Tests ◽

Effect Of Temperature ◽

Uniaxial Tensile ◽

Design And Manufacturing ◽

Manufacturing Procedure ◽

Short Time ◽

Versus Strain

In this paper, some interesting, experimentally determined actualities referring to the 50CrMo4 steel are presented. That way, the mechanical properties of the material are derived from uniaxial tensile tests at lowered and elevated temperatures. Engineering stress versus strain diagrams for both mentioned temperatures, curves representing the effect of temperature on specimen elongation, and short-time creep curves are given. Notch impact energy test was also carried out. Taking into consideration the service life of the final product of the mentioned steel widely used in engine and machine technology, all of the mentioned data may be relevant during design and manufacturing procedure.

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Regulation of Mechanical Properties of Advanced PCM Products with the Aid of Catalysts

Materials Science Forum ◽

10.4028/www.scientific.net/msf.992.415 ◽

2020 ◽

Vol 992 ◽

pp. 415-420

Author(s):

I.V. Zaychenko ◽

V.V. Bazheryanu ◽

A.G. Kim

Keyword(s):

Mechanical Properties ◽

Composite Materials ◽

Temperature Gradient ◽

Polymer Composite ◽

Strength Properties ◽

Polymer Composite Materials ◽

Epoxy Binder ◽

Curing Process ◽

The Matrix

The article considers the problem of the effect of uneven curing caused by the temperature gradient across the thickness of the material on the anisotropy of the strength properties of polymer composite materials. The effect of catalysts on the curing of the epoxy binder EDT-69N, used for the manufacture of multilayer polymer composite materials, was studied. According to dielectric spectrometry, the accelerating effect of the selected compounds on the curing process of the EDT-69N epoxy binder during fiberglass molding has been proved. The possibility of controlling the curing process using catalysts to reduce the influence of the temperature gradient on the anisotropy of the strength properties of the matrix in the manufacture of polymer composite materials is shown.

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A Study of Some Mechanical Properties of Composite Materials with a Dammar-Based Hybrid Matrix and Reinforced by Waste Paper

Polymers ◽

10.3390/polym12081688 ◽

2020 ◽

Vol 12 (8) ◽

pp. 1688

Author(s):

Marius Marinel Stănescu ◽

Dumitru Bolcu

Keyword(s):

Mechanical Properties ◽

Composite Materials ◽

Epoxy Resin ◽

Volume Ratio ◽

Tensile Tests ◽

Sem Analysis ◽

Waste Paper ◽

Hybrid Resin ◽

Natural Resin ◽

Tensile Response

When obtaining environment-friendly hybrid resins made of a blend of Dammar natural resin, in a prevailing volume ratio, with epoxy resin, it is challenging to find alternatives for synthetic resins. Composite materials reinforced with waste paper and matrix made of epoxy resin or hybrid resin with a volume ratio of 60%, 70% and 80% Dammar were studied. All samples obtained have been submitted to tensile tests and Scanning Electron Microscopy (SEM) analysis. The tensile response, tensile strength, modulus of elasticity, elongation at break and the analysis of the fracture surface were determined. The damping properties of vibrations of bars in hybrid resins and in the composite materials under study were also examined. The mechanical properties of the four types of resins and of the composite materials were compared. The chemical composition for a hybrid resin specimen were obtained using the Fourier Transformed Infrared Spectroscopy (FTIR) and Energy, Dispersive X-ray Spectrometry (EDS) analyzes.

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Mechanical Properties of Fibre-Metal Composites Connected by Means of Bolt Joints

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.837.296 ◽

2013 ◽

Vol 837 ◽

pp. 296-301

Author(s):

Sławomir Zolkiewski

Keyword(s):

Mechanical Properties ◽

Composite Materials ◽

Polyester Resin ◽

Steel Plate ◽

Fibrous Composite ◽

Laminate Plate ◽

Strength Properties ◽

Fibre Metal Laminates ◽

Fibre Metal ◽

The Impact

The fibre-metal laminates made of a steel plate and fibreglass laminate plate were tested in the special laboratory stands. Epoxy resin and polyester resin were used as matrix to fabricate the composites. The fibre-metal laminates combine advantages of metals and laminates. These materials have very good force versus displacement characteristics and overall mechanical properties. They are very popular and widely applied in technical systems. They can be put to use in connecting materials made of various fabrics, connecting high number layer laminates and most of all connecting metals and laminates. In this paper there are the results of testing fibrous composite materials connected in bolt joints presented. Composite materials reinforced with fiberglass, carbon and aramid fibers are considered. The impact of number of applied bolts in a joint on strength properties was investigated. The connections by means of eight or sixteen bolts were compared. A major problem of modelling the composites is assuming physical and material parameters of the analyzed elements.

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Determination of biofilm mechanical properties from tensile tests performed using a micro-cantilever method

Biofouling ◽

10.1080/08927011003793080 ◽

2010 ◽

Vol 26 (4) ◽

pp. 479-486 ◽

Cited By ~ 27

Author(s):

Srijan Aggarwal ◽

Raymond M. Hozalski

Keyword(s):

Mechanical Properties ◽

Tensile Tests ◽

Micro Cantilever

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Recycled Porcine Bone Powder as Filler in Thermoplastic Composite Materials Enriched with Chitosan for a Bone Scaffold Application

Polymers ◽

10.3390/polym13162751 ◽

2021 ◽

Vol 13 (16) ◽

pp. 2751

Author(s):

Marco Valente ◽

Jordi Puiggalí ◽

Luis J. del Valle ◽

Gioconda Titolo ◽

Matteo Sambucci

Keyword(s):

Composite Materials ◽

Preliminary Investigation ◽

Antibacterial Properties ◽

Tensile Tests ◽

Strength Properties ◽

Thermoplastic Composite ◽

Synthesis Process ◽

Electrospinning Technique ◽

Bone Powder ◽

Biological Tests

This work aims to synthesize biocompatible composite materials loaded with recycled porcine bone powder (BP) to fabricate scaffolds for in-situ reconstruction of bone structures. Polylactic acid (PLA) and poly(ε-caprolactone) (PCL) were tested as matrices in percentages from 40 wt% to 80 wt%. Chitosan (CS) was selected for its antibacterial properties, in the amount from 5 wt% to 15 wt%, and BP from 20 wt% to 50 wt% as active filler to promote osseointegration. In this preliminary investigation, samples have been produced by solvent casting to introduce the highest possible percentage of fillers. PCL has been chosen as a matrix due to its greater ability to incorporate fillers, ensuring their adequate dispersion and lower working temperatures compared to PLA. Tensile tests demonstrated strength properties (6–10 MPa) suitable for hard tissue engineering applications. Based on the different findings (integration of PLA in the composite system, improvements in CS adhesion and mechanical properties), the authors supposed an optimization of the synthesis process, focused on the possible implementation of the electrospinning technique to develop PCL-BP composites reinforced with PLA-CS microfibers. Finally, biological tests were conducted to evaluate the antibacterial activity of CS, demonstrating the applicability of the materials for the biomedical field.

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Stiffness and strength properties of five paperboards and their moisture dependency

TAPPI Journal ◽

10.32964/tj19.2.71 ◽

2020 ◽

Vol 19 (2) ◽

pp. 71-85

Author(s):

GUSTAV MARIN ◽

MIKAEL NYGARDS ◽

SOREN OSTLUND

Keyword(s):

Mechanical Properties ◽

Mechanical Property ◽

Shear Strength ◽

Three Dimensional ◽

Strength Properties ◽

Bending Stiffness ◽

Moisture Ratio ◽

Machine Direction ◽

Product Series

Five commercial multiply folding boxboards made on the same paperboard machine have been analyzed. The paperboards were from the same product series but had different grammage (235, 255, 270, 315, 340 g/m2) and different bending stiffness. The paperboards are normally used to make packages, and because the bending stiffness and grammage varies, the performance of the packages will differ. Finite element simulations can be used to predict these differences, but for this to occur, the stiffness and strength properties need to be deter-mined. For efficient determination of the three-dimensional properties in the machine direction (MD), cross direction (CD), and Z direction (ZD), it is proposed that the paperboard should be characterized using in-plane tension, ZD-tension, shear strength profiles, and two-point bending. The proposed setups have been used to determine stiff-ness and strength properties at different relative humidity (20,% 50%, 70%, and 90% RH), and the mechanical proper-ties have been evaluated as a function of moisture ratio. There was a linear relation between mechanical properties and moisture ratio for each paperboard. When the data was normalized with respect to the standard climate (50% RH) and plotted as a function of moisture ratio, it was shown that the normalized mechanical properties for all paperboards coincided along one single line and could therefore be expressed as a linear function of moisture ratio and two constants. Consequently, it is possible to obtain the mechanical properties of a paperboard by knowing the structural prop-erties for the preferred level of RH and the mechanical property for the standard climate (50% RH and 23°C).

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