Experimental analysis at different loading rates of 3D printed polymeric auxetic structure based on cylindrical elements

This work proposes the experimental study of an auxetic polymeric structure manufactured by 3D printing (SLA). The structure is composed by a re-entrant unit cell based on cylindrical elements not previously studied. The effect of the number and size/scale of the unit cells used in the specimens, subjected to both static and dynamic loads, has been analysed. The results show how the studied variables affect the behaviour of the structure in terms of stress and strain and that the dimensions of the cylindrical elements, as well as the contact between them, could help to modify the stiffness structure as required. The tests performed have allowed to understand the sequence of physical phenomena that appears at different strain rates and how they affect the response of the structure. The results obtained may contribute to the knowledge of both polymeric auxetic structures and the use of additive manufacturing methods for such structures.This research was funded by Ministerio de Asuntos Económicos y Transformación Digital, Gobierno de España grant number DPI2017-85073-R, and Vicerrectorado de Política Científica UC3M (Projects 2013/00413/003 and 2014/00006/003)