Fiber volume ratio

"Fiber volume ratio" is an important mathematical element in composite engineering.

$V\_f\; =\; frac\{v\_f\}\{v\_c\}!$ Isaac M Daniel, Ori Ishai. (2006)."Engineering Mechanics of Composite Materials". 2nd ed. Oxford University Press. ISBN-13: 978-0-19-532244-6]

where:

: $V\_f$ is the fiber volume ratio

and

: $v\_f$ is the volume of fibers: $v\_c$ is the volume of composite

One of the standardized method of determining the fiber volume ratio is the ignition or burnout method , described in ASTM specification D2584-02. The described method can be applied to composites containing inorganic fibers in an organic matrix .

Another standardized method is the acid digestion method which is explained in ASTM specification D3171-99. The method attacks the matrix that is acid-soluble but at the same time does not attack the fiber [(2004). "Space Simulation; Aerospace and Aircraft; Composite Materials" in "Annual book of ASTM Standards". Vol 15.03. American Society for Testing and Materials. West Conshohocken. PA. ] .

The fiber volume ratio is used to calculate the "void volume ratio".

$V\_v\; =\; 1\; -\; V\_f\; -\; V\_m\; =\; frac\; \{v\_v\}\{v\_c\}\; !$

where:

: $V\_v$ is the void volume ratio

and

: $V\_m$ is the matrix volume ratio: $v\_v$ is the volume of voids

References