Synthesis, characterization, and modelling the behavior of in-situ ZrO2 nanoparticles dispersed epoxy nanocomposite

•ZrO2 particles dispersed epoxy nanocomposites were fabricated through ultrasonic mixing.•A FE model is constituted for predicting macroscopic elastic properties of composites.•The model predicted location of fracture initiation under triaxial and uniaxial loading conditions.•Studied mechanical and viscoelastic behavior of nanocomposites.•Mechanical and viscoelastic properties improve with ZrO2 dispersion. The cured epoxy has poor toughness owing to highly cross-linked nature. The present work reports inclusion of ZrO2 nanoparticles with epoxy via ultrasonic mixing process for improving the toughness. The developed nanocomposites are characterized using mechanical tests, fractographic analysis and dynamic mechanical thermal analysis (DMTA). The mode-1 fracture toughness (K1C), fracture energy (G1C), storage modulus (E') and glass transition temperature (Tg) for different filler concentration are evaluated. A theoretical explanation for improved ZrO2-epoxy nanocomposite behaviour is reported by analyzing the fracture parameters and morphology of fractured samples. A micromechanical finite element (FE) model is constituted for predicting macroscopic elastic properties of composites using numerical homogenization scheme. The model predicted location of fracture initiation under triaxial and uniaxial loading conditions. The SEM micrographs and modelling results collectively explained the fracture mechanism. The experimentation and modelling results are compared.