▎ 摘　　要

A two-dimensional random model is developed to investigate the piezoresistive behavior of stacked graphene composites (SGCs). The theoretical value of gauge factor caused by graphene flakes sliding is determined and it is consistent with the simulation result. The relative resistances, gauge factors and morphologies of the model at different strain levels are obtained. These results reveal that sensing properties of SGCs come from the morphology change of graphene flakes. It is also confirmed that the relative sliding of overlapped graphene flakes leads to the linear sensing characteristics, and the disconnection of graphene flakes brings about the nonlinear sensing effect Additionally, the influence of length of graphene, initial resistance and pre-stretched treatment on sensing performance is investigated. These results can contribute to the improvement or innovation of SGCs for expected sensing performance. (C) 2019 Published by Elsevier Ltd.