scholarly journals Finite Element Modeling of the Fiber-Matrix Interface in Polymer Composites

2020 ◽  
Vol 4 (2) ◽  
pp. 58 ◽  
Author(s):  
Daljeet K. Singh ◽  
Amol Vaidya ◽  
Vinoy Thomas ◽  
Merlin Theodore ◽  
Surbhi Kore ◽  
...  
Keyword(s):  
Finite Element ◽  
Stress Distribution ◽  
Polymer Composites ◽  
Parametric Study ◽  
Single Fiber ◽  
Interface Debonding ◽  
Matrix Interface ◽  
The Matrix ◽  
Fiber Matrix Interface ◽  
Fiber Matrix

Polymer composites are used in numerous industries due to their high specific strength and high specific stiffness. Composites have markedly different properties than both the reinforcement and the matrix. Of the several factors that govern the final properties of the composite, the interface is an important factor that influences the stress transfer between the fiber and matrix. The present study is an effort to characterize and model the fiber-matrix interface in polymer matrix composites. Finite element models were developed to study the interfacial behavior during pull-out of a single fiber in continuous fiber-reinforced polymer composites. A three-dimensional (3D) unit-cell cohesive damage model (CDM) for the fiber/matrix interface debonding was employed to investigate the effect of interface/sizing coverage on the fiber. Furthermore, a two-dimensional (2D) axisymmetric model was used to (a) analyze the sensitivity of interface stiffness, interface strength, friction coefficient, and fiber length via a parametric study; and (b) study the shear stress distribution across the fiber-interface-matrix zone. It was determined that the force required to debond a single fiber from the matrix is three times higher if there is adequate distribution of the sizing on the fiber. The parametric study indicated that cohesive strength was the most influential factor in debonding. Moreover, the stress distribution model showed the debonding mechanism of the interface. It was observed that the interface debonded first from the matrix and remained in contact with the fiber even when the fiber was completely pulled out.

Prediction of the Fiber-Matrix Interface Failure due to Longitudinal Tensile Loading Using Finite Element Methods

1994 ◽  
Vol 365 ◽  
Author(s):  
Hassan Mahfuz ◽  
A.K.M. Ahsan Mian ◽  
Uday K. Vaidya ◽  
Timothy Brown ◽  
Shaik Jeelani
Keyword(s):  
Local Stress ◽  
Tensile Loading ◽  
Mechanical Tests ◽  
Matrix Interface ◽  
Interface Failure ◽  
Strain Behavior ◽  
The Matrix ◽  
Fiber Matrix Interface ◽  
Fiber Matrix ◽  
Composite Response

ABSTRACTA 3D-unit cell for 0/90 laminated composites has been developed to predict the composite behavior under longitudinal tensile loading condition. 3D contact element has been used to model the fiber matrix interface. Two interface conditions, namely, infinitely strong and weakly bonded, are considered in the analysis. Both large displacement and plastic strain behavior for the matrix are considered to account for the geometric and material non-linearities. Investigations were carried out at three temperatures to compare the composite response obtained from mechanical tests at those temperatures. Stress-strain behavior and the local stress distributions at the fiber as well as at the matrix are presented, and their effects on the failure of the interface are discussed in the paper. The material under investigation was SiCf/Si3N4.

scholarly journals Multiscale Characterization of Nanoengineered Fiber-Reinforced Composites: Effect of Carbon Nanotubes on the Out-of-Plane Mechanical Behavior

2017 ◽  
Vol 2017 ◽  
pp. 1-9 ◽  
Author(s):  
Carlos Medina ◽  
Eduardo Fernandez ◽  
Alexis Salas ◽  
Fernando Naya ◽  
Jon Molina-Aldereguía ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Carbon Nanotubes ◽  
Fracture Toughness ◽  
Shear Strength ◽  
Mechanical Behavior ◽  
Matrix Interface ◽  
Short Beam ◽  
The Matrix ◽  
Fiber Matrix Interface ◽  
Fiber Matrix

The mechanical properties of the matrix and the fiber/matrix interface have a relevant influence over the mechanical properties of a composite. In this work, a glass fiber-reinforced composite is manufactured using a carbon nanotubes (CNTs) doped epoxy matrix. The influence of the CNTs on the material mechanical behavior is evaluated on the resin, on the fiber/matrix interface, and on the composite. On resin, the incorporation of CNTs increased the hardness by 6% and decreased the fracture toughness by 17%. On the fiber/matrix interface, the interfacial shear strength (IFSS) increased by 22% for the nanoengineered composite (nFRC). The influence of the CNTs on the composite behavior was evaluated by through-thickness compression, short beam flexural, and intraply fracture tests. The compressive strength increased by 6% for the nFRC, attributed to the rise of the matrix hardness and the fiber/matrix IFSS. In contrast, the interlaminar shear strength (ILSS) obtained from the short beam tests was reduced by 8% for the nFRC; this is attributed to the detriment of the matrix fracture toughness. The intraply fracture test showed no significant influence of the CNTs on the fracture energy; however, the failure mode changed from brittle to ductile in the presence of the CNTs.

scholarly journals A Review on Natural Fiber-Reinforced Geopolymer and Cement-Based Composites

Materials ◽  
2020 ◽  
Vol 13 (20) ◽  
pp. 4603
Author(s):  
Marfa Camargo ◽  
Eyerusalem Adefrs Taye ◽  
Judith Roether ◽  
Daniel Tilahun Redda ◽  
Aldo Boccaccini
Keyword(s):  
New Technologies ◽  
Moisture Absorption ◽  
Natural Fiber ◽  
Natural Fibers ◽  
Industrial Applications ◽  
Synthetic Fiber ◽  
Matrix Interface ◽  
The Matrix ◽  
Fiber Matrix Interface ◽  
Fiber Matrix

The use of ecological materials for building and industrial applications contributes to minimizing the environmental impact of new technologies. In this context, the cement and geopolymer sectors are considering natural fibers as sustainable reinforcement for developing composites. Natural fibers are renewable, biodegradable, and non-toxic, and they exhibit attractive mechanical properties in comparison with their synthetic fiber counterparts. However, their hydrophilic character makes them vulnerable to high volumes of moisture absorption, thus conferring poor wetting with the matrix and weakening the fiber–matrix interface. Therefore, modification and functionalization strategies for natural fibers to tailor interface properties and to improve the durability and mechanical behavior of cement and geopolymer-based composites become highly important. This paper presents a review of the physical, chemical and biological pre-treatments that have been performed on natural fibers, their results and effects on the fiber–matrix interface of cement and geopolymer composites. In addition, the degradation mechanisms of natural fibers used in such composites are discussed. This review finalizes with concluding remarks and recommendations to be addressed through further in-depth studies in the field.

Fiber-Matrix Bonding in Boron-Reinforced Aluminum Composites

1969 ◽  
Vol 27 ◽  
pp. 32-33
Author(s):  
I. Corvin ◽  
H. Morrow ◽  
O. Johari ◽  
N. Parikh
Keyword(s):  
Aluminum Matrix ◽  
Surface Characteristics ◽  
Aluminum Matrix Composites ◽  
Matrix Composites ◽  
Matrix Interface ◽  
Boron Fiber ◽  
The Matrix ◽  
Fiber Matrix Interface ◽  
Fiber Matrix

A significant amount of research has been done in the past few years in the development of suitable composite materials in general and on boron fiber-aluminum matrix composites in particular. The mechanical properties of the composite depend on the structures and strengths of the matrix and fibers; on the amount, distribution, and surface characteristics of the fibers; and on the quality of the bond at the fiber-matrix interface. The results presented here illustrate the application of the SEM in studying the structure of the fiber-matrix interface and the fracture features of boron and aluminum.

Measuring Interface Strength in Single Fiber Composites: The Effect of Stress Concentrations

2000 ◽  
Vol 629 ◽  
Author(s):  
G. A. Holmes ◽  
R. C. Peterson
Keyword(s):  
Fragment Length ◽  
Interface Strength ◽  
Matrix Interface ◽  
Stress Concentrations ◽  
New Model ◽  
Testing Rate ◽  
Mechanics Model ◽  
The Matrix ◽  
Fiber Matrix Interface ◽  
Fiber Matrix

ABSTRACTFiber-matrix interface strength is known to be a critical factor in controlling the long-term performance of structural composites. This parameter is often obtained by using the average fragment length data generated from the single-fiber fragmentation test (SFFT). The interfacial shear strength is then determined by using this data in a micro-mechanics model that describes the shear-stress transfer process between the matrix and the fiber. Recently, a non-linear viscoelastic micro-mechanics model was developed to more accurately account for the matrix material properties. This new model indicates that the interface strength is dependent on the testing rate. Experimentally, it has been shown that the final fragment length distribution in some systems is dependent on the testing rate. However, data analysis using the new model indicates that the distribution change with testing rate is promoted by the presence of high stress concentrations at the end of the fiber fragments. From the model, these stress concentrations were found to exist at very low strain values. Experimentally, the fragment distributions obtained from specimens tested by different testing rates were found to be significantly different at strain values well below the strain values required to complete the test. These results are consistent with the research of Jahankhani and Galiotis and finite element calculations performed by Carrara and McGarry. These authors concluded that stress concentrations can promote failure of the fiber-matrix interface on the molecular level. Our results support this conclusion. In addition, our research results suggest that altering the SFFT testing rate can lower the magnitude of these stress concentrations and minimize failure of the fiber-matrix interface.

Transverse Stiffness Prediction of Fibrous Metal Matrix Composites

2014 ◽  
Vol 565 ◽  
pp. 14-19
Author(s):  
Gergis W. William ◽  
Samir N. Shoukry ◽  
Jacky C. Prucz
Keyword(s):  
The Other ◽  
Matrix Composites ◽  
Matrix Interface ◽  
Transverse Loading ◽  
Cooling Process ◽  
The Matrix ◽  
Fiber Matrix Interface ◽  
Fiber Matrix ◽  
Fibrous Metal ◽  
Packing System

This paper presents two new 3D finite element Multi Fiber Models (MFM) that account for the effects of neighboring fibers on the stress distribution over fiber-matrix interface. One model assumes a hexagonal packing pattern of the neighboring fibers whereas the other assumes that the neighboring fibers are packed in a square pattern. Two scenarios regarding the contact surface between the fiber and the matrix are considered: the first one assumes no bond over the interface while in the other one the interface is perfectly bonded. The cooling process of the composite was simulated and then a transverse loading is applied to the composite. The results indicate that packing system and the characteristics of the fiber-matrix interface greatly influence the magnitude of the residual stresses developed in the matrix.

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