PSI - Issue 14

Sarthak S. Singh et al. / Procedia Structural Integrity 14 (2019) 915–921 Author name / Structural Integrity Procedia 00 (2018) 000–000

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the considered low volume fractions) are often subjected to rigid body motion due to their non-directionality, thus minimally influencing the yield strength of the material. A computational analysis elucidating the influence of fillers on the post yield compression behaviour is discussed in the following section.

Figure 2. Stress vs. strain curves obtained by performing quasi-static compression experiments on spherical particles, reinforced epoxy composites

5. Computational Analysis A two dimensional elasto-plastic finite element simulation is carried out in ABAQUS-6.12. As illustrated in Fig. 3(a), the model consists of a block of epoxy of unit length and height (1 mm x 1 mm) extracted from the parent epoxy sample. This is equivalent to the Representative Volume Element (RVE) of neat epoxy sample. The stress vs. strain curve of neat epoxy obtained from the experiment is approximated to use in the simulations. The modified curve is presented by red dotted line in Fig. 3(b). The prime objective of the simulation is to understand the deformation mechanisms in the presence of filler particles when the composite is subjected to the compression and not to replicate the experimental results. The approximated engineering stress vs. strain curve is converted into true plastic stress - strain curve beyond the yield point by using the following equations and applied as the input in the material model section of ABAQUS.

(a)

(b)

Figure 3. (a) RVE of neat epoxy along with specified boundary conditions. (b) Approximation of the experimental engineering stress vs. strain curve.