Single fiber composite model

Fig. 4.4. Axi-symmelric single fiber composite model employed by Rosen (1964).

Fig. 4.6. Schematic drawing of a partially debonded single fiber composite model subject to external stress, (Ta, in the fiber fragmentation test.

In contrast, the single fiber composite model predicts that the IFSS concentration becomes higher at the embedded end than at the loaded end if fiber Kf is greater than a critical value, suggesting the possibility of debond initiation at the embedded fiber... 

Fig. 4.31. Distributions of (a) fiber axial stress and (b) interface shear stress along the axial direction obtained from micromechanics analysis for different fiber volume fractions, Vf = 0.03, 0.3 and 0.6 (—) single fiber composite (--------) three cylinder composite model. After Kim et al. (1994b).

One of the major differences between the results obtained from the micromechanics and FE analyses is the relative magnitude of the stress concentrations. In particular, the maximum IFSS values at the loaded and embedded fiber ends tend to be higher for the micromechanics analysis than for the FEA for a large Vf. This gives a slightly lower critical Vf required for the transition of debond initiation in the micromechanics model than in the FE model of single fiber composites. All these... 

The results presented in Section 4.3.6 suggest that the shear lag models based on a single fiber composite is inadequate for modelling a composite with a high fiber f). From the experimental viewpoint, to measure the relevant fiber-matrix interface properties, the fiber volume fraction in single fiber pull-out tests is always very low (i.e. Ff <0.01). This effectively means that testing with these specimens has the... 

Volume fiber 1/(Volume fiber 1 + volume of plastic in single fiber composite) Figure 4. Mathematical model—multifiber-reinforced thermoplastic... 

Favre, J.P. and Jacques, D. (1990). Stress transfer by shear in carbon fiber model composites Part I Results of single fiber fragmentation tests with thermosetting resins. J. Mater. Sci. 25, 1373-1380. 

Vautey, P. and Favre, J.P. (1990). Fiber/matrix load transfer in thermoset and thermoplastic composites-single fiber models and hole sensitivity of laminates. Composites Sci. Technol. 38, 271-288. 

Fig, 4.30. Schematic illustrations of the finite clement models of (a) single fiber pull-out specimen and (b) a three cylinder composite. After Kim ct al. (1994b). 

Favre, J.P. and Jacques, D. (1990). Stress transfer by shear in carbon fiber model composites Part I Results of single fiber fragmentation tests with thermosetting resins. J. Mater. Sci. 25, 1373-1380. Favre. J.P., Sigety, P. and Jacques, D. (1991). Stress transfer by shear in carbon fiber model composites. Part 2. Computer simulation of the fragmentation test. J. Mater. Sci. 26, 189-195. 

Some researchers have used approximate microscopic descriptions to develop more rigorous macroscopic constitutive laws. A microstructural model of AC [5] linked the directionality of mechanical stiffness of cartilage to the orientation of its microstructure. The biphasic composite model of [6] uses an isotropic fiber network described by a simple linear-elastic equation. A homogenization method based on a unit cell containing a single fiber and a surrounding matrix was used to predict the variations in AC properties with fiber orientation and fiber-matrix adhesion. A recent model of heart valve mechanics [8] accounts for fiber orientation and predicts a wide range of behavior but does not account for fiber-fiber interactions. 

Morris S, Hanna S and Miles MJ (2004) The self-assembly of plant wall components by single force specttoscopy and Monte Carlo modelling. Nanotechnology, 15,1296-301 Moslem A (ed) (1991) Inorganic bonded wood and fiber composite materials. Forest Products Society, Madison, Wisconsin... 

FIGURE 47.8 Comparison of predictions of Katz two-level composite model with the experimental data of Bonfield and Grynpas. Each curve represents a different lamellar configuration within a single osteon, with longitudinal fibers A, 64% B, 57% C, 50% D, 37% and the rest of the fibers assumed horizontal. (From Katz J.L., Mechanical Properties of Bone, AMD, vol. 45, New York, American Society of Mechanical Engineers, 1981. With permission.)... 

Whereas other bionic solutions in the field of composites are mostly founded on a single natural function, the seven different natural functionalities mentioned above were combined and translated into a concept of a technical fiber composite material with superior mechanical properties. A first computer modeling of the structure is shown in Rg. 9.12. The advantages of the new composite material were self-evident in such a way that specialists from prominent composite companies - seeing the FEM calculations and later the first prototypes of the technical plant stem - encouraged the inventors to patent this so-called technical plant stem . 

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