Mechanical response of nano-based composites is generally influenced by interaction of filler and matrix at interface. Increasing filler-loading within the composite may cause spatial limitation toward best dispersion of filler, and since synthesizing a totally agglomerated-free nanocomposite is difficult, filler and matrix interaction needs to be perfectly modeled. A micromechanical model is developed in this study based on the common Halpin-Tsai theory to predict the elastic stiffness of vinyl ester/exfoliated graphite platelet nanocomposites. The model considers near-rational ideal (uniformly dispersed) mixed with clustered filler-network to simulate filler-distribution conditions. A filler-dispersion level based on the filler concentration has been proposed mathematically in this study. Predictions of the proposed model considering filler morphology were compared with the predictions of the Halpin-Tsai model and the experimentally obtained results as well. The proposed model shows better accuracy in terms of stiffness over predictions of the HalpinTsai model and appears in a very good agreement with the experimental results obtained for vinyl ester nanocomposites.

In solid carbide end-mills, the flutes signiflcantly affect the tool's cutting performance and life, and the core radius mainly affects the tool's rigidity. The current CNC programming techniques can correctly determine the orientation of the wheel so that it grinds the rake face with the specifled rake angle; however, it cannot accurately determine the wheel location for the direct method and, consequently, the desired core radius is not guaranteed. To address this problem, a new CNC programming approach is proposed to accurately calculate the wheel orientation and location (WOLj in 5-axis grinding of the cylindrical end-milt flutes. In this work, a new concept of5-axis CNC grinding-effective grinding edge (EGE)-is first proposed to represent the instantaneous grinding edge of the wheel, and the parametric equations of the effective grinding edge are formulated. The wheel orientation and location in 5-axis flute grinding are calculated automatically and accurately so that the rake angle of the rake face and the core radius are ensured. The new approach is verified with several examples in this work. Therefore, it can improve the end-mill quality and lays a good foundation for the computer-aided design/ computer-aided engineering/computer-aided manufacttmng (CAD/CAE/CAM) of endmills.

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