Experimental analysis of compressive properties of arrowhead auxetic structure made by fused deposition modelling process

Since the 1980s, a new class of materials has been discovered called auxetic materials. These materials have a counterintuitive behaviour: when stretched longitudinally, they also expand in the perpendicular axis; when compressed longitudinally, they also become transversely thinner. They portray high indentation resistance, fracture toughness, and thermal fracture resistance. Auxetic materials are finding a variety of applications today, from aerospace usage, consumer goods, to the biomedical field, self-governing filters, springy shoe soles. In this study, compression behaviour of the arrowhead honeycomb auxetic structure sandwich has been analysed. These structures are 3D printed using polylactic acid (PLA) material. Further, the compressive properties of the sandwich structure are tested with different specimens by varying their gradient parameters. Nine specimens of varying parameters are tested, each with a different relative density due to changes in internal angles and arm length. The relationships between relative density against compressive strength is investigated.