Page 98 - Mechanics Analysis Composite Materials

Chapter 3. Mechanics of a unidirectional ply 83
)*, -”‘- *,“.*”‘-=.

Fig. 3.32. Testing of a microcomposite specimen ovenvrapped over discs.

In addition to fiber and matrix mechanical properties, micromechanical analysis
requires the information about the ply microstructure. Depending on the level of this
information, there exist micromechanical models of different levels of complexity.
The simplest or zero-order model of a ply is a monotropic model ignoring strength
and stiffness of the matrix and assuming that the ply works only in the fiber direc-
tion. Taking E2 = 0 and Glz = 0 in Eqs. (3.59) and putting vl2 = 0 in accordance
with Eq. (3.60) we arrive at the following equations describing this model

v-

Fig. 3.33. Testing of a microcomposite specimen gripped at the ends