Characterisation and Modelling of Particulate Composite with Flaky Aluminium Additives

The utilisation of flaky aluminium as an additive in the composite matrix has shown the ability to overcome the brittle nature encountered in epoxy resins. The additive increases the overall composite toughness without compromising its strength. The novelty of the present work is the demonstration of modelling the constitutive response of the particulate composite from the uniaxial tension tests conducted at three different displacement rates. Utilising two different mean-field homogenisation schemes (Dilute inclusion and Mori-Tanaka), the macro-scale properties were estimated and compared with the material constants obtained from experiments for this new particulate composite, which is proposed in the current study. The rate-independent response, at lower loading rates, is modelled by the elasto-plastic (EP) model, and the rate-dependent response, at higher loading rates, is modelled by elastic-viscoplastic (VP) model while capturing an inelastic deformation as seen in the fractographs. The EP and VP model material constants are then successfully obtained by optimisation employing the Levenberg–Marquardt algorithm and are eventually used in validating the experimental stress response.