Experimental Investigation on FDM Fabricated Tetra Chiral Auxetic Structures Under Uniaxial Compressive Loading

This chapter describes an experimental investigation on tetra chiral auxetic structures subjected to uniaxial compressive loading. The structures of polyethylene terephthalate glycol-modified (PET-G) material are manufactured by material extrusion technique, fused deposition modeling (FDM). The influence of geometric parameters of structures on responses namely strength, stiffness, plateau stress and specific energy absorption (SEA) under compressive loading is investigated. Two geometric parameters namely thickness of ligament (t) and radius of cylinder (r) are considered. Full factorial design is used for designing the experiments and then experimental results are analysed using analysis of variance. It is found that the radius of cylinder has significant effect on structure’s compressive strength and compressive modulus. With increase in radius of cylinder, compressive strength and compressive modulus decrease. Both thickness and radius are found influential for plateau stress. As the thickness increases the plateau stress decreases but with an increase in radius the plateau stress increases. Both parameters are found significant for SEA of structure. As the thickness increases, the SEA decreases, but with an increase in radius SEA initially decreases and then increases. Predictive models are also developed to correlate responses with parameters. Further, multi-objective optimization is performed for maximization of responses.