scholarly journals Evaluation of Interfacial Fracture Toughness and Interfacial Shear Strength of Typha Spp. Fiber/Polymer Composite by Double Shear Test Method

Materials ◽  
2019 ◽  
Vol 12 (14) ◽  
pp. 2225 ◽  
Author(s):  
Ikramullah ◽  
Samsul Rizal ◽  
Yoshikazu Nakai ◽  
Daiki Shiozawa ◽  
H.P.S. Abdul Khalil ◽  
...  
Keyword(s):  
Fracture Toughness ◽  
Shear Strength ◽  
Interfacial Shear Strength ◽  
Epoxy Composite ◽  
Interfacial Fracture ◽  
Interfacial Shear ◽  
Composite Model ◽  
Interfacial Fracture Toughness ◽  
Double Shear ◽  
The Matrix

The aim of this paper is to evaluate the Mode II interfacial fracture toughness and interfacial shear strength of Typha spp. fiber/PLLA and Typha spp. fiber/epoxy composite by using a double shear stress method with 3 fibers model composite. The surface condition of the fiber and crack propagation at the interface between the fiber and the matrix are observed by scanning electron microscope (SEM). Alkali treatment on Typha spp. fiber can make the fiber surface coarser, thus increasing the value of interfacial fracture toughness and interfacial shear strength. Typha spp. fiber/epoxy has a higher interfacial fracture value than that of Typha spp. fiber/PLLA. Interfacial fracture toughness on Typha spp. fiber/PLLA and Typha spp. fiber/epoxy composite model specimens were influenced by the matrix length, fiber spacing, fiber diameter and bonding area. Furthermore, the interfacial fracture toughness and the interfacial fracture shear stress of the composite model increased with the increasing duration of the surface treatment.

scholarly journals Multiscale Modeling of Fiber Fragmentation Process in Aligned ZnO Nanowires Enhanced Single Fiber Composites

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Parisa Marashizadeh ◽  
Mohammad Abshirini ◽  
Jingyu Wang ◽  
Mrinal C. Saha ◽  
Yingtao Liu
Keyword(s):  
Shear Strength ◽  
Multiscale Modeling ◽  
Interfacial Shear Strength ◽  
Fiber Composites ◽  
Interfacial Shear ◽  
Zno Nanowires ◽  
Single Fiber ◽  
Computational Domain ◽  
The Matrix ◽  
Fiber Fragmentation

AbstractA three-dimensional multiscale modeling framework is developed to analyze the failure procedure of radially aligned zinc oxide (ZnO) enhanced single fiber composites (SFC) under tensile loading to understand the interfacial improvement between the fiber and the matrix. The model introduces four levels in the computational domain. The nanoscale analysis calculates the size-dependent material properties of ZnO nanowires. The interaction between ZnO nanowires and the matrix is simulated using a properly designed representative volume element at the microscale. At the mesoscale, the interface between the carbon fiber and the surrounding area is modeled using the cohesive zone approach. A combination of ABAQUS Finite element software and the failure criteria modeled in UMAT user subroutine is implemented to simulate the single fiber fragmentation test (SFFT) at the macroscale. The numerical results indicate that the interfacial shear strength of SFC can be improved up to 99% after growing ZnO nanowires on the fiber. The effect of ZnO nanowires geometries on the interfacial shear strength of the enhanced SFC is also investigated. Experimental ZnO nanowires enhanced SFFTs are performed on the fabricated samples to validate the results of the developed multiscale model. A good agreement between the numerical and the experimental results was observed.

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.

Continuous Microindentation and Microscratch Measurements of Metal-Ceramic Adhesive strengths

1991 ◽  
Vol 239 ◽  
Author(s):  
S. Venkataraman ◽  
D. L. Kohlstedt ◽  
W. W. Gerberich
Keyword(s):  
Fracture Toughness ◽  
Strain Energy ◽  
Strain Energy Release Rate ◽  
Strain Energy Release ◽  
Interfacial Fracture ◽  
Interfacial Shear ◽  
Work Of Adhesion ◽  
Interfacial Fracture Toughness ◽  
Heat Treated ◽  
Metal Ceramic

ABSTRACTTo investigate the effect of heat-treatment on the adhesion of Pt thin films to NiO substrates, the strain energy release rate, interfacial fracture toughness and interfacial shear strength were determined from continuous microscratch and continuous microindentation experiments. Samples were prepared by sputtering Pt onto single crystals of NiO, followed by a heat-treatment at temperatures of 300, 500 and 800°C and an oxygen partial pressure of either 0.21 or 10-5 atm. Continuous microscratch tests were performed by driving a conical indenter with either a 1 or 5 μm tip radius simultaneously into and across the Pt film. From the magnitude of the critical load at the point of film delamination and the area of the delaminated piece of the thin film, the strain energy release rate (practical work of adhesion) and interfacial fracture toughness were calculated. The practical work of adhesion and interfacial fracture toughness increased from 0.2 J/m2 and 0.2 MPa√m, respectively, for as-sputtered samples to 4.6 J/m2 and 1 MPa√m for samples heat-treated at 500°C and 10-5 atm. Preliminary analysis of continuous microindentation results for Pt/NiO samples yielded interfacial shear strengths of 270 MPa for as-sputtered samples and 725 MPa for samples heat-treated at 500°C and 10-5 atm. While these values are in good agreement with those determined by other methods for metal-ceramic systems, there are sufficient differences in test method for a single system to require additional analysis of the proposed models.

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