Hybrid influences of interphase and grain-size on material responses of CNT-reinforced metal matrix composites

• Published in: Applied mathematical modelling 2024-01, Vol.125, p.313-328
• Main Authors: Yang, Junqiu, Bian, Lichun, Cheng, Yong
• Format: Article
• Language: English
• Subjects: Carbon nanotube; Elastoplastic behavior; Energy-based effective strain; Grain size; Interphase
• ISSN: 0307-904X
• DOI: 10.1016/j.apm.2023.08.047

•A nonlinear framework is based on field fluctuation approach, second-order stress moment.•The dislocation density model induced by grain size in metal matrix composite is proposed.•The energy-based effective strain is adopted to predict effective moduli of composites.•A coupled influence of interphase and metal grain-size on the nonlinear response is considered.•This study provides a perspective for material property prediction and optimizing design. In this investigation, a theoretical model is developed to consider the coupled influence of interphase and grain-size of metal on the nonlinear response of CNT-reinforced MMCs. A multiscale theoretical framework based on the energy-based effective strain method and the field fluctuation method is established. The second-order stress moment and dislocation density model are also adopted to predict the entire grain-size dependent stress-strain relations. The energy-based effective strain method is proposed to better exhibit the energy stored in the three-phase composites by replaced average-strain. The microstructure variables include volume fraction, moduli of interphase, geometrical size factor, aspect ratio of CNTs, and grain size in metal matrix. The accuracy of the present predictions is verified by some available experimental data. As a result, the proposed model can be used to define the mechanical behavior and make an optimum design of CNT reinforced MMCs as well as advanced engineering composites.