Insight into cell size effects on quasi-static and dynamic compressive properties of 3D foams

The aim of this paper is to investigate the cell size effects on the quasi-static and dynamic compressive properties of foams. Firstly, 3D Voronoi model is constructed to represent real foams, and then verified by the experiments conducted in our laboratory. By comparing the load vs. displacement curves, it is shown that the established model works well in studying the compressive properties of 3D foams. Furthermore, a new statistical method is proposed to establish the relationship between the microstructure parameters and the macro-properties of foams. This method can be used to clearly explain the size effect on the quasi-static and dynamic compressive properties of foams. Finally, the static and dynamic responses of the foams under compression are numerically implemented, and the size effects are investigated by considering the models with fixed density but different cell sizes. The results show that with increasing the cell size, Young's modulus of foams increases, whilst the plateau stress decreases under quasi-static compression. Under impact loading, the dynamic enhanced stress is insensitive to the cell sizes when the base material is rate independent, but is sensitive when the base material is rate dependent. The phenomena are also clearly explained by the proposed statistical method. (C) 2015 Elsevier B.V. All rights reserved.