scholarly journals Theoretical determination of the optimal fiber volume fraction and fiber-matrix property compatibility of short fiber composites

1993 ◽  
Vol 14 (2) ◽  
pp. 85-93 ◽  
Author(s):  
Ning Pan
Keyword(s):  
Fiber Volume Fraction ◽  
Volume Fraction ◽  
Fiber Composites ◽  
Short Fiber ◽  
Fiber Volume ◽  
Theoretical Determination ◽  
Matrix Property ◽  
Fiber Matrix

A New Theory for the Debonding of Discontinuous Fibers in an Elastic Matrix

1989 ◽  
Vol 170 ◽  
Author(s):  
Christopher K. Y. Leung ◽  
Victor C. Li
Keyword(s):  
Fiber Length ◽  
Fiber Volume Fraction ◽  
Volume Fraction ◽  
Interfacial Strength ◽  
Fiber Composites ◽  
Short Fiber ◽  
Fiber Volume ◽  
Physical Reason ◽  
Pull Out

AbstractThe mechanical properties of fiber composites are strongly influenced by the debonding of fibers. When an embedded fiber is loaded from one end, debonding can occur at both the loaded end and the embedded end. Existing theories neglect the possibility of debonding from the embedded end and are thus limited in applications to cases with low fiber volume fraction, low fiber modulus, high interfacial strength/interfacial friction ratio or short fiber length. A new twoway fiber debonding theory, which can extend the validity of one-way debonding theories to all general cases, has recently been developed. In this paper, the physical reason for the occurrence of two-way debonding is discussed. The limit of validity for one-way debonding theories is considered. One-way and two-way debonding theories are then compared with respect to the prediction of composite behaviour. The determination of interfacial parameters from the fiber pull-out test will also be described.

scholarly journals Micro-scale numerical study of fiber/matrix debonding in steel fiber composites

2020 ◽  
Vol 15 ◽  
pp. 155892502091072 ◽  
Author(s):  
Baris Sabuncuoglu ◽  
Stepan V Lomov
Keyword(s):  
Steel Fiber ◽  
Volume Fraction ◽  
Numerical Study ◽  
Glass Fibers ◽  
Fiber Composites ◽  
Steel Fibers ◽  
Opening Angle ◽  
Stress Concentrations ◽  
Fiber Volume ◽  
Fiber Matrix

Fiber/matrix debonding behavior of steel fiber composites is analyzed using a parametric finite element modeling procedure and compared with conventional composites with carbon and glass fibers. Cohesive surfaces are applied to fiber–matrix interface to simulate the debonding behavior, while the interface strength properties of steel fiber are obtained with and without surface treatment. The effect of various parameters on the debonding behavior is investigated, including stress concentrations, fiber diameter, fiber shape, and fiber volume fraction, using the parametric model. The influence of stress concentrations is determined to be much lower than the debonding strength. Debonding damage is more evident in larger fibers compared to smaller ones. Earlier and sudden interface separation is observed with the polygonal steel fibers compared to the circular ones. Increase in the fiber volume ratio increases the debonding opening distance but does not affect the opening angle significantly. The results can be useful for assessing possibilities to use steel fibers to increase toughness of the composites in comparison with glass and carbon reinforcement.

Determination of the Directional Dependent In-Plane Thermal Conductivity of K63B12 Pitch-Fiber/Epoxy Composite

2004 ◽  
Author(s):  
Jessica N. McClay ◽  
Peter Joyce ◽  
Andrew N. Smith
Keyword(s):  
Thermal Conductivity ◽  
Thermal Management ◽  
Fiber Volume Fraction ◽  
Volume Fraction ◽  
Epoxy Composite ◽  
Fiber Composite ◽  
Fiber Volume ◽  
State Technique ◽  
Fiber Composite Materials

Measurements of the in-plane thermal conductivity and the directional dependence of Mitsubishi K63B12 pitch-fiber/Epoxy composite from Newport Composites are reported. This composite is being explored for use in the Avanced Seal Delivery System for effective thermal management. The thermal conductivity was measured using a steady state technique. The experimental results were then compared to a model of the thermal conductivity based on the direction of the fibers. These estimates are based on the properties of the constituent materials and volume of fibers in the sample. Therefore the density and the fiber volume fraction were experimentally measured. The thermal conductivity is clearly greatest in the direction of the fibers and decreases as the fibers are rotated off axis. In the case of pitch fiber composite materials, the contribution of the fibers to the thermal conductivity dominates. The experimental data clearly followed the correct trends; however, the measured values were 25% to 35% lower than predicted.

scholarly journals A Revised Shear-Lag Analysis of an Energy Model for Fiber-Matrix Debonding

1996 ◽  
Vol 5 (5) ◽  
pp. 096369359600500 ◽  
Author(s):  
John A. Nairn ◽  
H. Daniel Wagner
Keyword(s):  
Unknown Parameter ◽  
Fiber Volume Fraction ◽  
Volume Fraction ◽  
Energy Model ◽  
Shear Lag ◽  
Fiber Volume ◽  
Shear Lag Model ◽  
Lag Model ◽  
Fiber Matrix ◽  
Stress Analyses

A shear-lag analysis based on energy is used to predict the amount of debonding that occurs when a fiber fragment breaks into two fragments. The shear-lag analysis reproduces all features of more sophisticated analyses. A drawback of the shear-lag analysis, however, is that it depends on an unknown parameter which can be expressed in terms of an effective fiber volume fraction. If the effective fiber volume fraction can be determined (by experiments or by advanced stress analyses), the shear-lag model can be used to interpret debonding experiments.

Fiber-Matrix Interfacial Area Reduction in Fiber Reinforced Cements and Concretes at Moderate to High Fiber Volume Fractions

1994 ◽  
Vol 370 ◽  
Author(s):  
Gebran N. Karam
Keyword(s):  
Mechanical Properties ◽  
Volume Fraction ◽  
Interfacial Area ◽  
Composite Fiber ◽  
Short Fiber ◽  
Published Data ◽  
Fiber Reinforced ◽  
Fiber Volume ◽  
High Fiber ◽  
Fiber Matrix

AbstractThe area and properties of the fiber-matrix interface in fiber reinforced cements and concretes determines the amount of stress transferred forth and back between the cement paste and the reinforcement and hence controls the mechanical properties of the composite. Fiber-fiber interaction and overlap of fibers with fibers, voids and aggregates can dramatically decrease the efficiency of the reinforcement by reducing this interfacial area. A simple model to account for this reduction is proposed and ways to integrate it in the models describing the mechanical properties of short fiber reinforced concretes are presented. The parameters of the model are evaluated from previously published data sets and its predictions are found to compare well with experimental observations; for example, it is able to predict the non-linear variation of bending and tensile strength with increasing fiber volume fraction as well as the existence of an optimal fiber content.

Can the Strength of Brittle Materials be Enhanced?

1992 ◽  
Vol 291 ◽  
Author(s):  
L. Monette ◽  
M. P. Anderson ◽  
G. S. Grest
Keyword(s):  
Computer Model ◽  
Random Distribution ◽  
Load Transfer ◽  
Volume Fraction ◽  
Fiber Composites ◽  
Short Fiber ◽  
Particulate Composites ◽  
Second Phase ◽  
Two Dimensional ◽  
Fiber Volume

ABSTRACTWe have employed a two-dimensional computer model to study the effect of volume fraction of second phase constituents on load transfer (stiffness) and strength in brittle short-fiber composites, i.e. composites containing a random distribution of aligned fibers, and brittle particulate composites. We find that the efficiency of load transfer to the second phase consituent increases with volume fraction in particulate composites, while it decreases for short-fiber composites. The strength of brittle particulate composites is found to decrease, while the strength of brittle short-fiber composites marginally increases only at fiber volume fractions equal or greater than 0.25.

Sign in / Sign up

Export Citation Format

Share Document