Where Ep and Vp represent the elastic modulus and the Poisson’s ratio of GMB material, and e and V represent the composite elastic modulus and Poisson’s ratio. In the calculation, ep and Ev are taken as 60 GPa and 0.21, respectively and the poisson’s ratio of all composites is taken as 0.35. The full expression for the model is lengthy and has no closed form solution; the reader is directed to the original article. Since this model is only applicable to plain syntactic foams, the experimentally measured modulus of various grades of CNF/epoxy are assigned to be the matrix modulus of corresponding grades of CNF/syntactic foams. For example, to predict the modulus of N5-220-15, the modulus of the N5 composite would be used as the matrix modulus.