Qualitative Investigations of Experiments Performed on 3D-FDM-printed Pantographic Structures Made out of PLA

Additive manufacturing methods, commonly known as 3D printing, enable the design and manufacturing of complex and sophisticated material fabrics with a special substructure resulting in extraordinary macroscopic deformation behavior. Such a man-made structure is also referred to as a metamaterial. So called pantographic structures, which can be described as metamaterials with a substructure that is composed of two orthogonal arrays of beams connected by internal cylinders, were manufactured using fused deposition modeling technique. In order to further understand the peculiarity of its deformation behaviors, a plane sheet was also printed to be used as a comparison. Different types of experiments were performed and evaluated qualitatively by the means of digital image correlation being able to localize the initial area of out-of-plane movements in shearing tests for both specimen. Results of quasi-static standard tension and shearing tests indicate a resilient material behavior during high elastic deformations resulting in a high resistance against total failure of the structure. Furthermore, cyclic long-term tests show a viscoelastic deformation behavior of the thermoplastic material. PSs show linear as well as non-linear elastic deformation response in all experiments except the cyclic tension test.