EXPERIMENTAL INVESTIGATION OF 3D PRINTED AUXETICS

Abstract

Auxetics, derived from the Greek word auxetikos, meaning "which tends to increase," are materials or structures characterized by a negative Poisson’s ratio (v); when these materi als are stretched in a certain direction, they usually become thinner in directions orthogonal to the direction of the applied force. As the main objective of the work was to study, de velop, and analyze additively manufactured (3D Printed) auxetic cores, software analysis and laboratory investigations were done on the nine samples. For the simulation frame work, 3D designs were generated using COMSOL Multiphysics since its greater efficiency and conformity with standard computers. Then, CAD files were generated and exported as STL files, a standard file for All (AM Technology) 3D printers. The models were developed through an iterative process of trial and error to ensure that the masses were similar. Ex perimental investigations were carried out, and the parts were printed using FDM printing techniques. For the FDM 3D Printer, ULTIMAKER 2 EXTENDED+andULTIMAKERCURA as slicer software was employed with ABS materials, Printing was kept 100 percent infill, and a 0.8mm nozzle size diameter was employed. The laboratory experiment that was con ducted to ascertain the deformation behavior of the nine printed samples was divided into two distinct parts: the first was the tensile testing, which was carried out on three dog bone (ASTM D638 Type IV) samples, and the second was the uniaxial compression test, which was conducted on six different models. The uniaxial compression test was performed on six models comprising every three specimens of hexagonal honeycombs and re-internet auxet ics, respectively. A static testing system and a digital camera on a tripod were used in all the tests.