Analysis of the random packing of identical particles V. Morphological properties of transversely isotropic fiber composites

1987 ◽  
Vol 26 (2) ◽  
pp. 106-111
Author(s):  
A. N. Nikolenko ◽  
M. S. Koval'chenko

1980 ◽  
Vol 47 (2) ◽  
pp. 329-334 ◽  
Author(s):  
Z. Hashin

Three-dimensional failure criteria of unidirectional fiber composites are established in terms of quadratic stress polynomials which are expressed in terms of the transversely isotropic invariants of the applied average stress state. Four distinct failure modes—tensile and compressive fiber and matrix modes—are modeled separately, resulting in a piecewise smooth failure surface.



2002 ◽  
Vol 69 (3) ◽  
pp. 292-302 ◽  
Author(s):  
Y. H. Zhao ◽  
G. J. Weng

In an effort to uncover the effect of interfacial partial debonding on the reduction of composite stiffness, a reduced moduli approach is proposed for the fictitious inclusions which are used to replace the original partially debonded inclusions. The fictitious inclusions are now perfectly bonded to the matrix and any micromechanical theory can be called upon to estimate the moduli of the composite. Using the volume of the inclusion directly beneath the interfacial cracks under the considered loading mode as a measure of damage, a set of anisotropic damage parameters is established in terms of the debonding angle, providing the reduced moduli for the fictitious inclusions. Specific considerations include debonding on the top and bottom of spheres and prolate inclusions, debonding on the lateral surface of spheres and oblate inclusions, and debonding on the top and bottom of circular fibers and elliptic cylinders. The reductions of the five transversely isotropic moduli for the partially debonded particle composites and the nine orthotropic moduli for the partially debonded fiber composites are examined as the debonding angle increases. The theory is also compared with some finite element results, and it suggests that the concept proposed to estimate the reduced moduli of the fictitious inclusions is a viable one.



1981 ◽  
Vol 48 (4) ◽  
pp. 846-852 ◽  
Author(s):  
Z. Hashin

Three-dimensional fatigue failure criteria for unidirectional fiber composites under states of cyclic stress are established in terms of quadratic stress polynomials which are expressed in terms of the transversely isotropic invariants of the cyclic stress. Two distinct fatigue failure modes, fiber mode, and matrix mode, are modeled separately. Material information needed for the failure criteria are the S-N curves for single stress components. A preliminary approach to incorporate scatter into the failure criteria is presented.



2011 ◽  
Vol 695 ◽  
pp. 469-472 ◽  
Author(s):  
Duangdao Aht-Ong ◽  
Duangduen Atong ◽  
Chiravoot Pechyen

This work involved a study of polymer-fiber composites as biodegradable packaging made from recycled polyethylene (r-PE) and chemical-treated cotton fabric waste micro fibers. A compatibilizer, polyethylene-graft-maleic anhydride (PE-g-MA), was used to improve properties of the composites. Factors affecting composite properties were investigated including % PE-g-MA loading, and % fiber loading. The fiber composites were prepared by melt-blending technique. The materials were first mixed by a twin-screw extruder and shaped into samples by an extrusion blow molding machine. The samples were then characterized for mechanical, and morphological properties. It was found that properties of the composites were improved by adding the compatibilizer. Optimum properties of the composites were found at 10% (wt%) PE-g-MA loading. It was also revealed that tensile strength and modulus was found to increase as the % fiber loading was increased. SEM micrographs confirmed that interfacial bonding between the cellulose fibers and the r-PE matrix was enhanced as fewer voids at the interfaces were revealed by adding the PE-g-MA compatibilizer to the composites. Film formation occurred on all composites even if the polymer itself was inert biodegradation. The microbial colonization affected mainly of surface properties r-PE composites while changes were monitored also in the bulk properties of cellulose microfiber.



1998 ◽  
Vol 120 (2) ◽  
pp. 110-113 ◽  
Author(s):  
R. M. Christensen

It is shown that there is a coordination between the numbers of the elastic properties and the numbers of the failure criteria parameters for aligned fiber composites under certain realistic conditions. These conditions require a high degree of anisotropy appropriate to polymeric matrix composites such that failure decomposes into separate fiber dominated and matrix dominated modes. Failure criteria are given in both five parameter and four parameter forms. The five parameter failure form coordinates with the usual five elastic property form for transversely isotropic composites. The four parameter failure form coordinates with a reduced four elastic property form which is shown to be applicable as an approximation for the same typical fiber composites.



Sign in / Sign up

Export Citation Format

Share Document