scholarly journals Micro- and Macromechanical Properties of a Composite with a Ternary PLA–PCL–TPS Matrix Reinforced with Short Fique Fibers

Polymers ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 58 ◽  
Author(s):  
José H. Mina ◽  
Alex Valadez González ◽  
Mario F. Muñoz-Vélez
Keyword(s):  
Mechanical Properties ◽  
Shear Strength ◽  
Interfacial Shear Strength ◽  
Thermoplastic Starch ◽  
Interfacial Shear ◽  
Weak Interface ◽  
Composite Matrix ◽  
Pull Out ◽  
Matrix Yielding ◽  
Fique Fibers

Biocomposites were prepared from a ternary matrix of polylactic acid (PLA), polycaprolactone (PCL), and thermoplastic starch (TPS) and reinforced with native fique fibers from southwestern Colombia. The influence of surface modification by alkalization of fique fibers on the interfacial properties of the biocomposite was studied using pull-out tests. Additionally, the effect of short fique fibers in three proportions (10%, 20%, and 30% (w/w)) on the tensile mechanical properties of the composite was evaluated. The experimental results indicated that the interfacial shear strength (IFSS) of the ternary matrix was predominantly influenced by PCL and characterized by the development of a weak interface that failed due to matrix yielding. Furthermore, the incorporation of short fique fibers increased the elastic modulus of the composite to values similar to those estimated with the Tsai–Pagano model. The alkalization treatment of the fique fibers improved the interface with the composite matrix, and this phenomenon was evidenced by the results of the micromechanical and tensile characterizations of the composite.

Effects of Temperature on the Fibre Matrix Interfacial Shear Strength of Carbon Nanotube Grafted Carbon Fibre Reinforced Heat Resistant Resin

2019 ◽  
Vol 827 ◽  
pp. 488-492
Author(s):  
Kazuto Tanaka ◽  
Daiki Kugimoto ◽  
Tsutao Katayama
Keyword(s):  
Mechanical Properties ◽  
Shear Strength ◽  
Carbon Fibre ◽  
Interfacial Shear Strength ◽  
Interfacial Shear ◽  
Pull Out ◽  
Significant Difference ◽  
Effects Of Temperature ◽  
Structural Parts ◽  
Fibre Matrix

Transportation sector is required to reduce CO2 emissions as environmental problems are becoming more serious. Carbon fibre reinforced thermoplastic (CFRTP) are expected to be applied to the structural parts of automobiles and aircrafts because of their superior mechanical properties such as high specific strength, high specific stiffness and high recyclability. One of the problems in using CFRTP for the structural parts is heat resistance, and it is necessary to clarify the mechanical properties under their service environmental temperature. The tensile strength of CFRTP at high temperatures decreases with temperature rise. The fibre matrix interfacial shear strength is reported to be improved by grafting of carbon nanotubes (CNTs) on the surface of carbon fibre. In this study, in order to clarify the effects of temperature on the fibre matrix interfacial shear strength of CNTs grafted carbon fibre reinforced PPS resin, single fibre pull-out test was conducted. While the interfacial shear strength of CNT grafted-CF/PPS is higher than that of As-received-CF/PPS at 25 °C, no significant difference was found in the interfacial shear strength of As-received-CF/PPS and CNT grafted-CF/PPS at 80 °C.

scholarly journals Effects of Water Absorption on the Fiber–Matrix Interfacial Shear Strength of Carbon Nanotube-Grafted Carbon Fiber Reinforced Polyamide Resin

2019 ◽  
Vol 3 (1) ◽  
pp. 4 ◽  
Author(s):  
Kazuto Tanaka ◽  
Saya Okuda ◽  
Yoshitaka Hinoue ◽  
Tsutao Katayama
Keyword(s):  
Mechanical Properties ◽  
Shear Strength ◽  
Carbon Fiber ◽  
Water Absorption ◽  
Interfacial Shear Strength ◽  
Interfacial Shear ◽  
Fiber Reinforced ◽  
Pull Out ◽  
Fiber Matrix ◽  
Carbon Fiber Reinforced

Carbon fiber reinforced thermoplastics (CFRTPs) are expected to be used for the structural parts of automobiles and aircraft due to their mechanical properties, such as high specific stiffness, high specific strength, short molding times and high recyclability. The fiber/matrix interface of the composite plays an important role in transmitting stress from the matrix to the reinforcing fibers. It was reported that grafting of carbon nanotubes (CNTs) on the carbon fiber can improve the fiber/matrix interfacial property. We have reported that CNTs, which are directly grafted onto carbon fiber using Ni as the catalyst by the chemical vapor deposition (CVD) method, can improve the fiber/matrix interfacial shear strength (IFSS) of carbon fiber/polyamide 6 (PA6). For practical use of CFRTPs, it is important to clarify the effects of water absorption on the mechanical properties of the composite material. In this study, the effects of water absorption on the fiber–matrix interfacial shear strength (IFSS) of carbon fiber reinforced polyamide resin and CNT-grafted carbon fiber reinforced polyamide resin were clarified by the single fiber pull-out test for specimens preserved in air, then in water for 24 h and re-dried after water absorption. The IFSS of carbon fiber/PA6 was significantly decreased by water absorption. In contrast, CNT-grafted carbon fiber/PA6 showed smaller degradation of the IFSS by water absorption.

scholarly journals A Special Single-Fibre Pull-Out Technique for Determining the Fiber/Cement Interfacial Bond Strength

2002 ◽  
Vol 11 (1) ◽  
pp. 096369350201100 ◽  
Author(s):  
J. M. Caceres ◽  
A. N. Netravali
Keyword(s):  
Shear Strength ◽  
Bond Strength ◽  
Interfacial Shear Strength ◽  
Single Fibre ◽  
Interfacial Shear ◽  
Specimen Geometry ◽  
Interfacial Bond ◽  
Interfacial Bond Strength ◽  
Pull Out ◽  
Fibre Cement

The paper discusses a simple specimen geometry to obtain the fibre/cement interfacial shear strength (IFSS). The specimens are easy to prepare and easy to test. The technique gives reliable and reproducible results. IFSS results for five different fibres with cement were measured. Most IFSS values obtained are in the range of 0.15 to 1.5 MPa. Despite the simplicity of the technique presented in this study, the results are in agreement with those obtained by several other researchers using different techniques and specimen geometry.

scholarly journals Shear Behaviors of the Intersurface between Rice Straw Rope and Dredger Fill Silt: Experimental and Mechanism Studies

2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Guizhong Xu ◽  
Ji Chen ◽  
Shenjie Shi ◽  
Angran Tian ◽  
Qiang Tang
Keyword(s):  
Shear Strength ◽  
Normal Stress ◽  
Rice Straw ◽  
Immersion Time ◽  
Interfacial Shear Strength ◽  
Land Reclamation ◽  
Tensile Force ◽  
Interfacial Shear ◽  
Pull Out ◽  
Dredger Fill

The further development of land reclamation, port waterway, and wharf construction brings about proper treatments of dredger fill silt, while huge amounts of rice straw set aside in China argument rational disposal every year. Therefore, rice straw is bundled up as ropes, which represent as drainage body and reinforcement, to make eco-friendly treatment for dredger fill silt. This paper investigates the mechanical properties and validity of rice straw rope as certain treating material of dredger fill silt through a series of pull-out test, mass loss test, and tension test on specimens with different water contents and dry densities. The results reveal that peak value of interfacial shear strength rises with the increase of normal stress at the same immersion time, and in particular, it rises by up to 250.0% when the normal stress is 40 kPa. The tensile force of rice straw rope increases slowly with the rise of tensile displacement, and the failure mode changes from brittle to ductile with the rise of immersion time, which witnesses first rapid back slow degradation trend. The proper interfacial shear strength, tensile force, and reasonable degradation rate of rice straw rope make it ideal in drainage and consolidation of dredger fill silt.

scholarly journals Why Should the “Alternative” Method of Estimating Local Interfacial Shear Strength in a Pull-Out Test Be Preferred to Other Methods?

Materials ◽  
2018 ◽  
Vol 11 (12) ◽  
pp. 2406
Author(s):  
Serge Zhandarov ◽  
Edith Mäder ◽  
Uwe Gohs
Keyword(s):  
Shear Strength ◽  
Interfacial Shear Strength ◽  
Traditional Approach ◽  
Interfacial Shear ◽  
Frictional Stress ◽  
Displacement Curve ◽  
Pull Out ◽  
Alternative Method ◽  
Fiber Reinforced Materials ◽  
Force Displacement

One of the most popular micromechanical techniques of determining the local interfacial shear strength (local IFSS, τd) between a fiber and a matrix is the single fiber pull-out test. The τd values are calculated from the characteristic forces determined from the experimental force–displacement curves using a model which relates their values to local interfacial strength parameters. Traditionally, the local IFSS is estimated from the debond force, Fd, which corresponds to the crack initiation and manifests itself by a “kink” in the force–displacement curve. However, for some specimens the kink point is hardly discernible, and the “alternative” method based on the post-debonding force, Fb, and the maximum force reached in the test, Fmax, has been proposed. Since the experimental force–displacement curve includes three characteristic points in which the relationship between the current values of the applied load and the crack length is reliably established, and, at the same time, it is fully determined by only two interfacial parameters, τd and the interfacial frictional stress, τf, several methods for the determination of τd and τf can be proposed. In this paper, we analyzed several theoretical and experimental force–displacement curves for different fiber-reinforced materials (thermoset, thermoplastic and concrete) and compared all seven possible methods of τd and τf calculation. It was shown that the “alternative” method was the most accurate and reliable one, while the traditional approach often yielded the worst results. Therefore, we proposed that the “alternative” method should be preferred for the experimental force–displacement curves analysis.

scholarly journals Experimental and Numerical Study of the Interfacial Shear Strength in Carbon Fiber/Epoxy Resin Composite under Thermal Loads

2018 ◽  
Vol 2018 ◽  
pp. 1-8 ◽  
Author(s):  
Hongxiao Wang ◽  
Xiaohui Zhang ◽  
Yugang Duan ◽  
Lingjie Meng
Keyword(s):  
Shear Strength ◽  
Carbon Fiber ◽  
Epoxy Resin ◽  
Interfacial Shear Strength ◽  
Numerical Study ◽  
Resin Composite ◽  
Interfacial Shear ◽  
Thermal Loads ◽  
Mechanical Coupling ◽  
Pull Out

This study examined the influence mechanism of temperature on the interfacial shear strength (IFSS) between carbon fiber (CF) and epoxy resin (EP) matrices under various thermal loads using experimental and numerical simulation methods. To evaluate the change in IFSS as a function of the increase in temperature, a microbond test was performed under controlled temperature environment from 23°C to 150°C. The experimental results showed that IFSS values of CF/EP reduce significantly when the temperature reaches near glass transition temperature. To interpret the effect of thermal loads on IFSS, a thermal-mechanical coupling finite element model was used to simulate the process of fiber pull-out from EP. The results revealed that temperature dependence of IFSS is linked to modulus of the matrix as well as to the coefficients of thermal expansion of the fiber and matrix.

Pull-out method for direct measuring the interfacial shear strength between short plant fibers and thermoplastic polymer composites (TPC)

Holzforschung ◽  
2014 ◽  
Vol 68 (1) ◽  
pp. 17-21 ◽  
Author(s):  
Hao Wang ◽  
Genlin Tian ◽  
Hankun Wang ◽  
Wanju Li ◽  
Yan Yu
Keyword(s):  
Shear Strength ◽  
Polymer Composites ◽  
Interfacial Shear Strength ◽  
Interfacial Shear ◽  
Thermoplastic Polymer ◽  
Plant Fibers ◽  
Important Indicator ◽  
Pull Out ◽  
Research Activities ◽  
The Matrix

Abstract Thermoplastic polymer composites reinforced with short plant fiber are worldwide in focus of research activities. Interfacial shear strength (IFSS) is an important indicator for evaluating the bonding quality between the fiber and the matrix polymer. However, the direct measurement of IFSS is especially difficult in the case of short fibers. In the present article, a method is proposed to this purpose, which is related to the known “fiber pulling out” methodology. In the case of single bamboo fibers, the IFSS in a polypropylene (PP) matrix was on, an average, of 5 MPa, which can be considered as weak. Scanning electron microscopy images revealed a rough inner surface in PP cavities left after fiber pulling out. This is direct evidence that a mechanical interlocking mechanism is active in the interphase between the hydrophilic fibers and the hydrophobic matrix.

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