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 Fracture toughness of unidirectional flax fiber composites with rigid gliadin matrix

2018 ◽  
Vol 37 (18) ◽  
pp. 1163-1174 ◽  
Author(s):  
Nhan Vo Hong ◽  
Kristel Beckers ◽  
Bart Goderis ◽  
Peter Van Puyvelde ◽  
Ignaas Verpoest ◽  
...  
Keyword(s):  
Fracture Toughness ◽  
Weak Links ◽  
Matrix Interface ◽  
Interface Quality ◽  
Fiber Treatment ◽  
The Matrix ◽  
Initiation Fracture Toughness ◽  
Fiber Matrix Interface ◽  
Fiber Matrix

The aim of this study is to improve the interlaminar fracture toughness of flax/gliadin composites. Some key parameters are used such as processing conditions, matrix plasticization, and fiber treatment. These parameters affect the crack-growth resistance since they are, respectively, related to the cross-linking density by varying the cooling conditions, to the reduction of the brittleness by adding a low amount of plasticizer, and to the quality of the fiber–matrix interface. Results show that interface quality is more dominant than the effect of a low amount of plasticizer for the initiation fracture toughness value. While crack initiation is closely related to weak links such as the fiber–matrix interface, crack propagation appears to be mainly in the matrix.

Thermomechanical Stability of Interphases in Glass Reinforced Composites

1989 ◽  
Vol 170 ◽  
Author(s):  
A. T. Dibenedetto ◽  
Jaime A. Gomez ◽  
C. Schilling ◽  
F. Osterholtz ◽  
G. Haddad
Keyword(s):  
Thermal Stability ◽  
Shear Strength ◽  
Glass Fibers ◽  
Boiling Water ◽  
Reinforced Composites ◽  
Matrix Interface ◽  
Force Transmission ◽  
Silane Coating ◽  
Fiber Matrix Interface ◽  
Fiber Matrix

AbstractThe thermomechanical stability of organosilane surface treatments for E-glass fibers used in fiber reinforced composites was evaluated. The effect of molecular structure of 40 to 80 namometer coatings on the force transmission across the fiber/matrix interface was measured as a function of temperature and exposure to water using a fiber fragmentation test. It was found that phenyl-substituted amino silanes exhibited better thermal stability, but were less resistant to boiling water, than the commierically available γ-amino propyl silanes. A bis-trimethoxy γ-amino propyl silane showed an increase in both the hydrolytic and thermal stability when compared to the commiercial product. A good balance of thermal and hydrolytic stability was also obtained with a methylaminopropyltrimethoxy silane coating.The strain energy released from the glass fibers upon decoupling from the poxy matrix or silane coating was found to be in the range of 145 to 186 g/m2 and varied no more than 20 percent over a temperature range of 25 to 75°C or when exposed to boiling water and then redried. It also varied very little with the silane coating used. In addition, the average shear stress attained at the fiber-matrix interface in an imbedded single fiber test at 25°C was as much as two times higher than the shear strength of the epoxy matrix and as much as five times higher at elevated temperature. These data lead one to the conclusion that the interphase failure in these composites is controlled by a plane strain fracture in the constrained region of the organic phase, near the fiber surface, rather than by the maximum shear strength in the interphase.

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.

Evaluation of Mechanical Properties and Comprehensive Modeling of CMC with Stiff and Weak Matrices

2006 ◽  
Vol 45 ◽  
pp. 1435-1443 ◽  
Author(s):  
Dietmar Koch ◽  
Kamen Tushtev ◽  
Jürgen Horvath ◽  
Ralf Knoche ◽  
Georg Grathwohl
Keyword(s):  
Mechanical Properties ◽  
Mechanical Response ◽  
Ceramic Matrix Composites ◽  
High Strength ◽  
Shear Mode ◽  
Matrix Composites ◽  
Matrix Interface ◽  
Strain Behavior ◽  
Fiber Matrix Interface ◽  
Fiber Matrix

The mechanical properties of ceramic matrix composites (CMC) depend on the individual properties of fibers and matrix, the fiber-matrix interface, the microstructure and the orientation of the fibers. The fiber-matrix interface of ceramics with stiff matrices (e.g. CVI-derived SiC/SiC) must be weak enough to allow crack deflection and debonding in order to achieve excellent strength and strain to failure (weak interface composites WIC). This micromechanical behavior has been intensively investigated during the last 20 years. With the development of CMC with weak matrices (weak matrix composites WMC) as e.g. oxide/oxide composites or polymer derived CMC the mechanical response can not be explained anymore by these models as other microstructural mechanisms occur. If the fibers are oriented in loading direction in a tensile test the WMC behave almost linear elastic up to failure and show a high strength. Under shear mode or if the fibers are oriented off axis a significant quasiplastic stress-strain behavior occurs with high strain to failure and low strength. This complex mechanical behavior of WMC will be explained using a finite element (FE) approach. The micromechanical as well as the FE models will be validated and attributed to the different manufacturing routes.

scholarly journals Fiber-matrix Interface Mechanical Properties of Carbon-Carbon Composites

2009 ◽  
Vol 7 (ists26) ◽  
pp. Pc_67-Pc_72 ◽  
Author(s):  
Ken GOTO ◽  
Miho ISHII ◽  
Hiroshi HATTA ◽  
Hitoshi KOHRI ◽  
Ichiro SHIOTA
Keyword(s):  
Mechanical Properties ◽  
Carbon Composites ◽  
Matrix Interface ◽  
Fiber Matrix Interface ◽  
Fiber Matrix

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.

Sign in / Sign up

Export Citation Format

Share Document