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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m vm  values show an increasing trend with increase in the filler volume fractions. Looking

Beyond 0.3 strain values,

at the m pl  values after 0.3 strain values from Fig. 5(b), it can be observed that these magnitudes are larger than 0.3, meaning that they are on the hardening regime of the true stress vs. strain curve of neat epoxy system. Therefore, the stress level keeps on rising with increase in the strain values beyond 0.3 strain levels. When 22 f  values are plotted for the circular fillers (Refer, Fig. 5(d)), it is interesting to note that these values overlap on top of each other with increase in the volume fraction of the circular fillers, indicating that the optimum inter-particle separation is not reached which would result in the interaction of the stresses amongst the circular particles. Hence from all these plots it can be concluded that the rise in the stress values with increase in the volume fractions of the fillers in the hardening regime is due to the hardening behaviour in the filler reinforced matrix and the circular fillers have negligible influence on it. 6. Conclusion The effect of volume fraction on the quasi-static compression behaviour of low volume fraction glass filled epoxy composites is demonstrated. The yield and post yield stresses for the spherical particle reinforced epoxy composites are marginally affected due to larger inter-particle separation at low volume fractions. To get more insight into the influence of filler shape on the deformation mechanisms in post yielding regime, a computational study is performed where a set of inclusions surrounded by the epoxy matrix is modeled and the materials’ deformation response to the compressive loading is analyzed by conducting a two dimensional elasto-plastic finite element simulations. From these analyses , it is revealed that the compressive stresses in the fillers are not affected with increase in the filler volume fraction; but the Mises stresses in the matrix increases with the increase in the filler volume fraction in the hardening regime of the plastic flow curve. References ASTM D695-10; Standard test method for compressive properties of rigid plastics. Herbold, E.B., Nesterenko, V.F., Benson, D.J., Cai, J., Vecchio, K.S., Jiang, F., Addiss, J.W., Walley, S.M. and Proud, W.G., 2008. Particle size effect on strength, failure, and shock behavior in polytetrafluoroethylene-Al-W granular composite materials. Journal of Applied Physics , 104 (10), p.103903. Jordan, J.L., Richards, D.W., White, B., Thadhani, N.N. and Spowart, J.E., 2007. High Strain Rate Mechanical Properties of Epoxy and Epoxy Based Particulate Composites (No. AFRL-MN-EG-TP-2007-7410). AIR FORCE RESEARCH LAB EGLIN AFB FL MUNITIONS DIRECTORATE. Kawaguchi, T. and Pearson, R.A., 2003. The effect of particle–matrix adhesion on the mechanical behavior of glass filled epoxies: Part 1. A study on yield behavior and cohesive strength. Polymer , 44 (15), pp.4229-4238. Mallick, P.K. and Broutman, L.J., 1975. Mechanical and fracture behaviour of glass bead filled epoxy composites. Materials Science and Engineering , 18 (1), pp.63-73. Ma, P., Jiang, G., Li, Y. and Zhong, W., 2015. The Impact Compression Behaviors of Silica Nanoparticles—Epoxy Composites. Journal of Textile Science and Technology , 1 (01), p.1. Omar, M.F., Akil, H.M. and Ahmad, Z.A., 2013. Particle size–Dependent on the static and dynamic compression properties of polypropylene/silica composites. Materials & Design , 45 , pp.539-547. Yesgat, A.L. and Kitey, R., 2016. Effect of filler geometry on fracture mechanisms in glass particle filled epoxy composites. Engineering Fracture Mechanics , 160 , pp.22-41.