Akademik Veri Yönetim Sistemi
COST ACTION CA21121 - European Network for the Mechanics of Matter at the Nano-Scale (MecaNano), Madrid, İspanya, 26 - 27 Nisan 2023, ss.43
Improvement of the interfacial bonding between nanofiller and matrix and homogenous dispersion of nanofiller on the matrix are two main issues in the manufacturing of polymer matrix nanocomposites. To get an improved mechanical properties, first, graphene nanoflakes (GNF) are functionalized using Triton X-100. Then, the f-GNF-epoxy nanocomposites are manufactured by three-roll milling for two different graphene fractions (0.1 and 0.5 wt%). Thermogravimetric analysis, X-ray diffraction tests, Raman Spectroscopy, and FourierTransform Infrared Spectroscopy (FT-IR) were performed for the structural characterization of graphene. The viscoelastic { viscoplastic behavior of nanocomposites are investigated by performing Dynamic Mechanical Analysis (DMA), creep, and compression tests. Rate dependency in compression and stress dependency on creep were modeled by using cooperative-viscoplasticity theory based on overstress (C-VBO) for the nanocomposite model. In the recently developed nanocomposite material model, the unified state variable VBO theory which consists of two tensor valued and one scalar state variables with a flow law is taken as base. This material model which covers the total time, temperature, and nanofiller fraction has been developed over the years by Colak. The Mori-Tanaka homogenization scheme is used in order to define modulus values as a function of nanofiller fraction. For the stiffening effect of graphene in viscoplastic region, Takayanagi averaging approach is used as well. All behaviors mentioned above are simulated and good agreement with the experimental results is obtained.