Determination of Viscoelastic Response of Interphase Region in Carbon Fiber Reinforced Epoxy Using AFM Indentation
The interphase region in fiber reinforced polymer (FRP) composites exhibits time dependent behavior due to the viscoelasticity of the matrix. AFM based (Atomic Force Microscopy) indentation utilizing different dwell periods for various constant loads are employed to analyze the creep behavior of the near–fiber region in carbon fiber reinforced epoxy. It is observed that along a radial line to the fiber, the relaxation of the polymer is lower closer to the fiber. Loading in the interphase region is known to be influenced by the fiber constraint effect. Therefore, 3D FE (Finite Element) simulations using an assumed non-linear elastic and linear viscoelastic behavior of epoxy is used to determine the extent of the influence of the fiber constraint on the viscoelastic response of the interphase region.
KeywordsCarbon fiber reinforced composites Viscoelasticity Fiber constraint AFM indentation
This material is based upon work supported by the National Science Foundation under Grant No. 1649481.