احمدعلي نيري

The objective of this research is to investigate the effect of 3D printer manufacturing variables on the fatigue life of components. Considering the advantages of additive manufacturing an‎d its increasing application in various industries, studying the mechanical properties of the produced parts is of particular importance. One of the critical aspects in this field is the fatigue life of 3D-printed components. Among additive manufacturing technologies, fused deposition modeling (FDM) printers, which use polymeric filaments, are among the most common fabrication systems in industries. In the process of 3D printing, several variables such as printing speed, material type, nozzle temperature, bed temperature, layer orientation, an‎d layer thickness significantly influence the fatigue life of the printed parts. In this study, polylactic acid (PLA) material was first characterized. Then, five printing parameters—printing angle, printing speed, layer thickness, printing temperature, an‎d layer width—were selec‎ted to eva‎luate their effect on the mechanical properties of the parts. To minimize the number of required tests, design of experiments (DOE) an‎d response surface methodology (RSM) were employed. The results of static tests revealed the optimal an‎d most influential parameters affecting the mechanical strength of the printed components. Given the layer-by-layer nature of 3D-printed parts an‎d their similarity to polymeric composite laminates, the behavior of the printed components was compared with predictions from Classical Laminate Theory (CLT). The results indicated that although the overall behavior of both groups was similar, significant differences were observed between the experimental properties of the printed parts an‎d the predictions of CLT. Subsequently, after identifying the optimal parameters through static tests, the fatigue behavior of 3D-printed components was eva‎luated. Fatigue tests were carried out on samples with 0°, ±45°, an‎d 90° layer orientations, an‎d stress–life (S–N) curves were plotted for each case. The results demonstrated that specimens with 90° layer orientation exhibited greater scatter in fatigue life compared to other orientations. In addition, thermal conditions of the printed specimens were monitored during fatigue testing using an infrared thermal camera.

چاپ سه‌بعدي , عمر خستگي , FDM , مشخصه‌هاي چاپ سه بعدي , رفتار خستگي

3D printing , fatigue life , FDM , printing parameters

Ahmadali Nayyeri

Prof. M.M. Shokrieh