Elastic Modulus of the Interphase in Organic Matrix Composites

1989 ◽  
Vol 170 ◽  
Author(s):  
J. G. Williams ◽  
M. E. Donnellan ◽  
M. R. James ◽  
W. L. Morris
Keyword(s):  
Elastic Modulus ◽  
Matrix Material ◽  
Organic Matrix ◽  
Normal Matrix ◽  
Matrix Composites ◽  
Model Composite ◽  
Fiber Treatment ◽  
The Matrix ◽  
Organic Matrix Composites ◽  
Reinforcing Fiber

AbstractIn organic matrix composites the properties of the matrix in the vicinity of the reinforcing fiber are of interest [1]. It has been suggested that a volume of material surrounding the fiber is significantly different from the bulk matrix [2–6]. Recent work has indicated that the interphase layer may be softer than the normal matrix material [6]. For a model composite with a single fiber embedded in an epoxy/amine matrix this layer was observed to be about 500nm thick and the material had an average elastic modulus of about 1/4 of that of the normal matrix material. The objective of the present work is to observe the effect of fiber treatment on the elastic properties of the interphase.

Anisothermic Oxidation of Carbon/Epoxy Laminates

Aerospace ◽  
2006 ◽  
Author(s):  
W. Trabelsi ◽  
V. Bellenger ◽  
E. Ghorbel
Keyword(s):  
Organic Matrix ◽  
Numerical Results ◽  
Oxidation Products ◽  
Matrix Cracking ◽  
Matrix Composites ◽  
Radical Chain ◽  
The Matrix ◽  
Organic Matrix Composites ◽  
C 50 ◽  
Differential Expansion

This work deals with the ageing of a carbon epoxy composite material for aeronautic and supersonic applications. One of the main parameters which governs the durability of this kind of materials is the matrix oxidation, which is limited to surface layers. The long-term behaviour of organic matrix composites includes combined effects of ageing: matrix oxidation occurring at high temperature and matrix cracking due to thermo-mechanical ply stresses induced by differential expansion between matrix and fibers or between the various plies. For some years ENSAM has developed for isothermal conditions a kinetic model of radical chain oxidation coupled with the equation of oxygen diffusion. This model is based on a "close-loop" oxidation mechanistic scheme and gives access to the concentration profile of oxidation products in the sample thickness. In this work we expressed the temperature by a Fourier series and we simulate the oxidative behaviour of samples exposed to the following thermal cycles: -50°C/+180°C, -50°C/+150°C and +50°C/+180°C. The weight loss of the oxidised samples was chosen as indicator of oxidation. Numerical results are compared to experimental ones to check the validity of the model. Good agreement between experimental and numerical results is obtained.

Interply Behavior Exhibited in Compliant Filamentary Composite Laminates

1982 ◽  
Vol 55 (4) ◽  
pp. 1078-1094 ◽  
Author(s):  
J. L. Turner ◽  
J. L. Ford
Keyword(s):  
Shear Strain ◽  
Composite Laminates ◽  
Matrix Material ◽  
Matrix Composites ◽  
Efficient Manner ◽  
Strain Behavior ◽  
The Matrix ◽  
Order Of Magnitude ◽  
Extensional Strain ◽  
Interlaminar Shear

Abstract Cord-rubber composite systems allow a visualization of interply shear strain effects because of the compliant nature of the matrix material. A technique termed the pin test was developed to aid this visualization of interply shear strain. The pin test performed on both flat pads and radial tires shows that interlaminar shear strain behavior in both types of specimens is similar, most of the shear strain being confined to a region approximately 10 interly rubber thicknesses from the edge. The observed shear strain is approximately an order of magnitude greater than the applied extensional strain. A simplified mathematical model, called the Kelsey strip, for describing such behavior for a two-ply (±θ) cord-rubber strip has been formulated and demonstrated to be qualitatively correct. Furthermore, this model is capable of predicting trends in both compliant and rigid matrix composites and allows for simplified idealizations. A finite-element code for dealing with such interply effects in a simple but efficient manner predicts qualitatively correct results.

scholarly journals Extraction of void fraction in metal matrix composite using morphological image processing

1994 ◽  
Vol 3 (2) ◽  
pp. 096369359400300
Author(s):  
Lun X. He ◽  
David K. Hsu ◽  
John P. Basart
Keyword(s):  
Image Processing ◽  
Void Fraction ◽  
Metal Matrix ◽  
Volume Fraction ◽  
Matrix Material ◽  
Void Content ◽  
Matrix Composites ◽  
Cross Sectional ◽  
Morphological Image Processing ◽  
The Matrix

In continuous fiber reinforced metal matrix composites, the volume fraction of voids in the matrix material is an important parameter for material property characterization. In analyzing a cross-sectional micrograph of such a composite, the presence of fiber images and voids occurring on the perimeter of fibers complicates the determination of void content. This paper describes image processing steps using mathematical morphology for the extraction of void fraction in a composite.

Modeling matrix fracture in fiber-reinforced ceramic-matrix composites with different fiber preforms

2019 ◽  
Vol 90 (7-8) ◽  
pp. 909-924 ◽  
Author(s):  
Longbiao Li
Keyword(s):  
Elastic Modulus ◽  
Ceramic Matrix Composites ◽  
Interface Debonding ◽  
Matrix Composites ◽  
Multiple Fracture ◽  
Fiber Volume ◽  
Interface Shear ◽  
Interface Shear Stress ◽  
The Matrix ◽  
Fiber Preforms

In this paper, the stress-dependent matrix multiple fracture in silicon carbide fiber-reinforced ceramic-matrix composites with different fiber preforms is investigated. The critical matrix strain energy criterion is used to determine the matrix multiple fracture considering the interface debonding. The effects of the fiber radius, fiber elastic modulus, matrix elastic modulus, fiber volume, interface shear stress, and interface debonded energy on the matrix multiple fracture and the interface debonding are analyzed. The experimental matrix multiple cracking and interface debonding of minicomposite, unidirectional, and two-dimensional woven SiC/SiC composites with different fiber volumes and interphases are predicted. The matrix cracking density increases with the increasing of the fiber volume, fiber elastic modulus, interface shear stress, and interface debonded energy, and the decreasing of the fiber radius and matrix elastic modulus.

Interaction between Cracking and Oxidation in Organic Matrix Composites

2005 ◽  
Vol 39 (15) ◽  
pp. 1371-1389 ◽  
Author(s):  
X. Colin ◽  
A. Mavel ◽  
C. Marais ◽  
J. Verdu
Keyword(s):  
Organic Matrix ◽  
Matrix Composites ◽  
Organic Matrix Composites

Kinematically Designed Flexible Skins for Morphing Aircraft

Aerospace ◽  
2006 ◽  
Author(s):  
Christine Pastor ◽  
Brian Sanders ◽  
James J. Joo ◽  
Robin McCarty
Keyword(s):  
Shape Memory Polymer ◽  
Matrix Material ◽  
Optimization Techniques ◽  
Heat Transfer Analysis ◽  
Material Response ◽  
Morphing Aircraft ◽  
The Matrix ◽  
Link Density ◽  
Cross Link Density ◽  
Reinforcing Fiber

This investigation targeted the development of flexible materials that when combined with mechanized structures can enable large rigid body deformations of aircraft structures while maintaining its aerodynamic shape. The solution presented in this work focuses on determining the distribution of material properties to design such a skin using topology optimization techniques. The matrix material selected in this research is a representative Shape Memory Polymer (SMP), which is embedded with a reinforcing fiber. The fiber plays a dual role in that in addition to serving as a reinforcing element it also provides the means to activate the material response (e.g., changing cross link density) via resistive heating. In depth heat transfer analysis and experiments were conducted to understand power requirements and minimum spacing of the fibers to activate the desired material response.

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