# Composite Materials/weight fraction

Question
QUESTION: sir, I am frabricated specimens of coir and epoxy with hand lay up method ,as per 30:70,40:60,50:50 weight fraction,suppose I have taken 10 gm fiber web,what are the resin weight for above mentioned ratios?

ANSWER: If you search my archived responses in this site you will find the answer because I have responded to this question before.
You need to know or measure the density of coir and epoxy.
The equations are easy.
The are in chapter 4 of my 2011 textbook.

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QUESTION: Dont mind sir,I does not get answer,density of coir fiber is 1.2gm/cm3 and density of epoxy resin is 1.1 gm/cm3.Can you tell me,for coir fiber and epoxy resin what should be range of mixing?

Use Eq. (4.8) in this textbook: http://barbero.cadec-online.com/icmd/index.html
1/rho_c = W_f/rho_f + W_m/rho_m
where (c) composite, (f)fiber, (m) matrix.

Also:

There you need fiber volume fraction.
To convert from weight (W) to volume (V) fraction, use Eq. (4.9)

Fiber:
W_f = rho_f/rho_c * Vf
Matrix:
W_m = rho_m/rho_c * Vm

Composite Materials

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#### Ever Barbero

##### Expertise

Structural Mechanics, Mechanics of Materials, Structural Analysis, Material Modeling (numerical, analytical), Testing (mechanical, aging, etc.) of Composites and Polymers, mainly Polymer Matrix and to lesser extent Materials Science and Processing of same. See http://mysite.verizon.net/everbarbero/

##### Experience

Working with Composites since 1983, two patents.

Organizations
Fellow, Society for the Advancement of Materials Process Engineering SAMPE
Fellow, American Society of Mechanical Engineers ASME
Member, American Society for Testing Materials ASTM
Member, American Institute of Aeronautics and Astronautics AIAA
Member, American Society of Engineering Education ASEE

Publications
100+ peer reviewed papers on every major journal on composites and mechanics
Introduction to Composite Materials Design, ISBN: 1-56032-701-4, http://www.mae.wvu.edu/barbero/icmd/
Finite Element Analysis of Composite Materials, ISBN: 1-4200-5433-3, http://www.mae.wvu.edu/barbero/feacm/

Education/Credentials
PhD Engineering Science, 1989, Virginia Tech.
BSME, BSEE, 1983, UNRC.

Education/Credentials
PhD Engineering Science, 1989, Virginia Tech.
BSME, BSEE, 1983, UNRC.

Awards and Honors
SAMPE Fellow (2006).
ASME Fellow (2003).
Best Overall Paper Award, Combined Composite Expo’99 and ASCE Materials Conference’99, Cincinnati, OH.
Best Paper Award, 1999 ASME J. of Composites for Construction, Vol. 4, No. 4, p. 185-191.
MAE Alumni Academy Award for Outstanding Teaching, 1999.