Hello,
We know from experiments in different papers that when jute/epoxy and banana/epoxy (for example) with elastic modulus (E1) of 6 GPa and 11 GPa respectively, are embedded together in epoxy, the new banana/jute/banana hybrid composite yields a new elastic modulus of 14 GPa, which is greater than each of jute/epoxy and banana/epoxy. Numerically and also analytically this is not possible. Because numerically and analytically we can expect that the hybrid composite will show an E1 value in between 6 GPa and 11 GPa.
That means we are missing something in numerical and analytical solution. Have any of you done a brainstorming on it ? how experimentally we are getting 14 GPa of E1 value? What are we missing in our analytical calculations?
Any feedback regarding this would highly be appreciated. Thanks!
Dear Muhammad,
pl go thru the attached paper, especially the reported modulus of banana fiber in table 2. I think that the reported value justifies the value of 14 GPa in the hybrid composite.
Synergy is the mechanism with which we explain positive hybrid effect. This occurs when you consider the voigt ( parallel) model rather than the reuss( series) model. The reuss model can explain only the negative hybrid effect. The truth is that hybrid modulus is a function of both voigt and reuss models in combination as decided by the contiguity factor that is between o and 1 depending on volume fraction, i.e, how away or closer the fibres are to each other. At extremes you get no synergy. When the elastic mismatch between the fibre and the matrix is not as high as that of glass or carbon with epoxy, added to the fact that banana or jute bond well with epoxy, the fracture mechanisms are also decided by the interfacial properties and inter fibre spacing. The optimum of these gives you the best synergy. Please read Bryan Harris for the Voigt and Reuss models.
I think that there is a mistake in definition of modules or volume fractions of fibers. Personally to me values of the module of 14 GPA seem overestimated.
It is necessary to know as you have measured the module and what was a share of the reinforcing fibers.
The correct answer to your question is possible only at the accounting of volume fractions of the reinforcing fibers. Creating a hybrid, you could increase a total volume fraction of fibers.
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