Chemistry Reference
In-Depth Information
(18)
(19)
The composite density
ρ
calculated as follows:
(20)
(21)
These equations can be used to determine the void fraction:
(22)
The mass fraction of fibers can be measured by removing the matrix.
Based on the first concept, the linear elasticity, the linear relationship be-
tween the total stress and infinitesimal strain tensors for the reinforcement
and matrix as expressed by the following constitutive equations:
(23)
(24)
where C is the stiffness tensor.
The second concept is the average stress and strain. While the stress
field and the corresponding strain field are usually nonuniform in poly-
mer composites, the average stress and strain are then defined over the
representative averaging volume V, respectively. Hypothesize the stress
field in the RVE is . Then, composite stress is defined by:
(25)
