Preliminary investigations on auxetic structures based on recycled rubber

Abstract

The growing demand for tyres in transport industry provides a negative impact on the environment, due to the problems related to recycling and disposal of the rubber waste. However, adding waste tyres as a dispersive phase in polymeric composites has shown high toughness and moderate increase of mechanical strength within the composites. In this work, we investigate the use of recycled rubber core to manufacture auxetic (re‐entrant) honeycomb structures. The re‐entarnt honeycombs produced are evaluated using finite element analysis and tensile in‐plane to assess the sensitivity of the mechanical properties versus the cell geometric parameters. A full factorial design (33) was performed to investigate the effects of the factors width (10 and 20 mm), thickness (2 and 4 mm) and angle (−10 and −20°) on Poisson's ratio of honeycomb structures. The results give further evidence that the Poisson's ratio is affected not only by individual factors but also by interaction originated by the other geometric parameters.

Partially auxetic behavior in fcc crystals of hard-core repulsive Yukawa particles

“…Depending on whether negative values of Poisson ratio are observed in all crystallographic directions, in some of them or in none of them, one can define all materials as auxetics, partial auxetics and nonauxetics, respectively (). Recently, increasing interest in studies of auxetic materials and models was observed .…”

Auxetic Materials and Related Systems

“…A further class of materials which is investigated in this issue is that of auxetic composites. Thaís A.A. Silva and co‐workers 12 investigated the use of recycled rubber core composites to manufacture auxetic re‐entrant honeycombs. The authors show that the Poisson's ratio of this honeycomb is dependent on width‐to‐thickness ratio as well as the interaction effect between the ‘width and angle’ and ‘angle and thickness’.…”

Failure analysis and Taguchi design of auxetic recycled rubber structures

“…The rubber particles were shredded, washed, and dried at 80°C for 24 h and classified by sieving in size range of 100/200 US‐Tyler (0.149/0.079 mm). According to Panzera et al and Silva et al the composite fabricated with 25% of rubber particle size of 100/200 US‐Tyler has shown improved mechanical and physical properties. The addition of 25% of rubber particles into polymeric matrix has shown higher particle packing factor and energy absorption, besides contributing to recycle rubber wastes from scrap tyres.…”