SCALE-UP OF TRANSFORMATION OF NEGATIVE POISSONS RATIO FOAM - SLABS

This paper presents an experimental study performed on the scale-up of processing of negative Poisson's ratio foam. These materials become t hinner under compression and fatter under tension, opposite to ordinar y materials. The transformation process consists of triaxial compressi on combined with heat treatment. Transformed foam cells have a concave or ''re-entrant'' shape. Scale-up is achieved by use of a modified mo uld assembled around the foam slab and longer processing times. Foam w ith a distribution of cell sizes was transformed in small block and la rge slab forms. These blocks and slabs exhibited a negative Poisson's ratio.