Compressive properties of cell structures with cell shape anisotropy

Abstract

In the previous study, authors have investigated the effect of foam structure on compressive properties of foamed PE film using various foam structure specimens. This result suggested that the cell structure, aspect ratio of the cell shape, of the specimen significantly affects compression properties. In this research, based on the past experimental study, the mechanism of the effect of cell structure was investigated using numerical experiment. To investigate of the effect of cell shape, a simple morphology and repetition model was used. A model consists of upper, lower rigid walls and cell wall. Three models with different aspect ratios were prepared to evaluate the effect of cell shape aspect ratio. The compressive numerical experiments were performed by applying the constant velocity in the upper rigid wall. The constant velocities were 0.75 and 7.5 m/s (initial strain rate: 5.0×10¹ s^-1 and 5.0×10¹ s^-1). As a result of numerical examination, it was confirmed that when the aspect ratio of cell shape was different, the deformation mode changed due to the difference in the curvature of the cell wall at the initial stage of the deformation. It was found that the difference in this deformation mode influences the slope of the elastic response. From this result, it was clarified that the slope of the elastic response is caused by the difference of the aspect ratio of the cell.