Experimental investigation of the effect of process parameters of fused filament fabrication on the efficient elastic material properties of the lattice structures produced

Although Additive Manufacuring Technology was used for rapid prototyping when it first emerged, it has been frequently used in the aviation-space and defense industry, automotive, medical and energy sector today. Especially, due to their hollow structures such as lattice structures, the ability to produce complex structures that provide lightness, layer by layer, it has increased the research on the producibility of lattice structures with these production techniques and their usability in industry. Although there are many different Additive Manufacturing techniques, Fused Filament Fabrication (FFF) technique is widely preferred due to its low cost. However, it is known that FFF process parameters have major effects on the mechanical properties of the produced parts. In the literature, most of the studies on the effects of FFF process parameters on mechanical properties are on fully filled samples. Therefore, the purpose of this study is to examine the effects of process parameters on the effective material properties of lattice sturctures proced by FFF. Polylactic Acid (PLA) was used for the material of the samples to be produced with this technique. In this study, three different basic lattice structure types, Simple Cubic (SC), Body Centered Cubic (BCC) ABSTRACT vii and Face Centered Cubic (FCC) were selected. The parameters which have the greatest effect on the effective elastic material properties of the samples are supported by the research in the literature have been selected. For this purpose, three levels were determined for each of the process parameters for FFF, such as layer thickness, nozzle temperature and printing speed. While designing the experiments, Taguchi Method was used. Compression tests of lattice samples produced for different process parameter value groups determined by Taguchi method were performed. Compressive modulus and compression strength results were obtained from these tests. In order to compare the effects of FFF process parameters on these properties, analysis of variance (ANOVA) method was used with the help of MATLAB program. In the production of these lattice structures, the required parameter values have been determined in order to have the highest elastic properties. The findings obtained will be a useful resource to throw light on studies on lattice structures and to start replacing fully filled structures used in engineering applications with lattice structures.