Problem Statement:

The figures shown below are geometric surface representations of elastic properties for unidirectional fiber-reinfoced graphite/epoxy The elastic properties shown here are choosen because they best demonstrate anisotropy. For unidirectional composites materials, anisotropy is largely controlled by fiber anisotropy and fiber volume fraciton.

For unidirectional composites the plane transverse to the X3 "fiber" axis is "transversely isotropic". In this transverse plane there is no variation of elastic properties and all graphical plots would be seen as circles. Hence polar plots in the X3-X 2 plane show the only variation in elastic composite properties.

The objective here is to observe the largest variation in elastic properties as geometric polar plots. These geometries represent anisotropy as outlined by Nye, Ref[6]. More detailed information on the polar plots shown here are taken from Ref[9], "Elastic Representation Surfaces of Unidirectional Graphite/Epoxy Composites".





Young's modulus of unidirectional Graphite/Epoxy, Gpa
X3 - Fiber axis






Shear modulus of unidirectional Graphite/Epoxy, Gpa
X3 - Fiber axis






Poisson's ratio of unidirectional Graphite/Epoxy
X3 - Fiber axis


Course content in this section: email Dr. Ron Kriz
http://www.jwave.vt.edu/~rkriz/crcd/modules/module02/Prob_Def.html
Created November 1997 / Modified January 1, 2001