Micromechanical modeling for the temperature-dependent yield strength of polymer-matrix nanocomposites

Abstract

Research in the mechanical performance of advanced materials and structures at low and high temperatures and the relationship between physical quantities via theoretical modeling is a rapidly growing area. According to the Force-Heat Equivalence Energy Density Principle, micromechanical models combined with the shear-lag analysis and Halpin-Tasi method were developed to predict the temperature-dependent yield strength of nanoparticle-, nanofiber- and nanoplate-reinforced polymer-matrix nanocomposites. The proposed models considered the combined effects of nanofiller dimension, orientation, volume fraction and the evolution of Poisson's ratio, Young's modulus, and load transfer caused by the interface shear with the temperature. And the quantitative relationship between the above physical quantities was established. Compared with the classical models, the proposed models did not involve fitting parameters and were in better agreement with the available published experimental data at different temperatures. Furthermore, the quantitative effects of polymer Young's modulus and nanofiller volume fraction on the yield strength of nanocomposites at different temperatures were investigated by the proposed model. This research benefits a convenient and reliable prediction for the yield strength of polymer-matrix nanocomposites in a wide temperature range and could offer theoretical basis to the optimal design for better performance in engineering applications.