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.

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.

Damping in Unidirectional and Cross-Ply Ceramic Matrix Composites With Matrix Cracks

2001 ◽  
Author(s):  
Victor Birman ◽  
Larry W. Byrd
Keyword(s):  
Ceramic Matrix Composites ◽  
Ceramic Matrix ◽  
Interfacial Friction ◽  
Matrix Composites ◽  
Matrix Interface ◽  
Unidirectional Composites ◽  
Matrix Cracks ◽  
Dissipation Of Energy ◽  
Fiber Matrix Interface ◽  
Fiber Matrix

Abstract The paper elucidates the methods of estimating damping in ceramic matrix composites (CMC) with matrix cracks. Unidirectional composites with bridging matrix cracks and cross-ply laminates with tunneling cracks in transverse layers and bridging cracks in longitudinal layers are considered. It is shown that bridging matrix cracks may dramatically increase damping in unidirectional CMC due to a dissipation of energy along damaged sections of the fiber-matrix interface (interfacial friction). Such friction is absent in the case of tunneling cracks in transverse layers of cross-ply laminates where the changes in damping due to a degradation of the stiffness remain small. However, damping in cross-ply laminates abruptly increases if bridging cracks appear in the longitudinal layers.

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.

Fiber/matrix interface stress analysis of flax-fiber composites under transverse loading considering material nonlinearity

2020 ◽  
Vol 39 (9-10) ◽  
pp. 345-360
Author(s):  
Baris Sabuncuoglu ◽  
Onur Cakmakci ◽  
Fevzi S Kadioglu
Keyword(s):  
Fiber Composites ◽  
Flax Fiber ◽  
Material Nonlinearity ◽  
Transverse Strain ◽  
Matrix Interface ◽  
Transverse Loading ◽  
Stress Concentrations ◽  
Transverse Cracks ◽  
Fiber Matrix Interface ◽  
Fiber Matrix

Distribution of stresses in fiber/matrix interface in UD flax fiber reinforced composites is investigated under transverse loading and compared with conventional synthetic fibers. Micro-scale finite element models with representative volume elements are generated with various fiber packing types and fiber volume ratios. The study is performed for various strain values, which take into account the material nonlinearity of matrix. The results show that significantly lower stress concentrations exist in the case of flax fibers compared to glass fiber composites, explaining the absence of transverse cracks until failure in previously conducted transverse tension tests. Increase in the applied transverse strain causes a further decrease in the stress concentrations due to the nonlinear behavior of the matrix.

The Contribution of Matrix Plasticity to the “Frictional” Sliding of Debonded Fibers in Sapphire-Reinforced TiAl Matrix Composites

1994 ◽  
Vol 350 ◽  
Author(s):  
J. M. Galbraith ◽  
D. A. Koss ◽  
J. R. Hellmann
Keyword(s):  
Material Removal ◽  
Large Scale ◽  
Tial Alloy ◽  
Dominant Role ◽  
Matrix Composites ◽  
Matrix Interface ◽  
Frictional Sliding ◽  
Sic Fiber ◽  
The Matrix ◽  
Fiber Matrix Interface

AbstractLarge-scale fiber displacement behavior, usually characterized by a “frictional” sliding stress (τslide), has been studied in two sapphire-reinforced TiAl systems. Experimental results from fiber pushout and reverse push-back tests indicate that the large-scale sliding behavior of debonded fibers leads to an average τslide-value which progressively decreases during fiber displacements. Previous studies of SCS-6 (SiC) fiber-reinforced glass and metal matrix composites have attributed decreases in τslide to the fracture and wear of fiber asperities. However, given a matrix in which fiber asperities do not easily wear (e.g., a TiAl alloy), SEM examination of the fiber/matrix interface indicates that matrix plasticity plays a dominant role in the decrease of τslide with fiber displacement. Experimental evidence suggests that the observed decrease in τslide can be attributed to (1) a decrease in fiber roughness perceived by the matrix due to matrix grooving and (2) a relaxation of radial clamping as a result of material removal from the interface.

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 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.

Structure and behavior of metal/ceramic interfaces in Ti alloy/SiC metal matrix composites

1993 ◽  
Vol 8 (5) ◽  
pp. 1158-1168 ◽  
Author(s):  
Ernest L. Hall ◽  
Ann M. Ritter
Keyword(s):  
Metal Matrix Composites ◽  
Reaction Zone ◽  
Metal Matrix ◽  
Ti Alloy ◽  
Matrix Composites ◽  
Matrix Interface ◽  
Fiber Coating ◽  
Sic Particles ◽  
Fiber Matrix Interface ◽  
Fiber Matrix

The structure and mechanical behavior of the fiber/matrix interface in Ti alloy/SCS-6 SiC metal matrix composites were studied. In these composites the interface region consists of a fiber-coating region and a metal reaction zone between the SiC fiber body and the metal matrix. The fiber coating consists of a number of zones or layers which are comprised of cubic SiC particles in a turbostratic carbon matrix. Some ambiguity remains, concerning the number of distinct layers and the size, shape, and density of the SiC particles. The effect of composite fabrication and heat treatment on the coating structure is relatively small. Studies of the metal reaction zone adjacent to the fiber in Ti alloy/SCS-6 SiC MMC's have shown that a number of discrete zones or layers form. Nearest the fiber, a zone of cubic TiC occurs, with increasing grain size with distance from the fiber. Nearest the metal matrix, a zone of Ti5Si3 forms. In high Al content alloys, an intermediate zone forms that consists of Ti2AlC or Ti3AlC. The fiber/matrix interface plays an important role during transverse tensile loading of these composites. The tensile behavior is controlled by debonding at the interface, followed by deformation of the matrix ligaments. Replica observations show that the debonding initiates and propagates within the coating layers, but is not confined to a single layer interface.

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