Comparison of Tensile Strength for 3D Printed Parts Fabricated by Fused Deposition Modeling (FDM)

Additive manufacturing is a new type of manufacturing process which is used for the fabrication of special parts in a minimum possible time. Unlike the machining processes in which the part is prepared by material removal, the parts are fabricated in additive manufacturing by adding a new layer to old printed layers. In this article, the tensile strength of printed specimens from ABS by Fused Filament Fabrication (FFF) will be evaluated. Size, in-fill density, and the print pattern are three process parameters that will be investigated. Three different size samples, five different in-fill density samples, and two samples with different patterns are printed and the stress-strain behavior of prepared samples was compared. The tensile test results show that the tensile strength of samples decreases by increasing the sample size. Also, by decreasing the in-fill density, the tensile load of samples and elongation decreases, and a considerable difference between the 100% in-fill density and other samples are observed. By comparing the ratio of maximum force to the mass of samples it was observed that this ratio is almost constant for non-solid samples but this ratio is 25% higher for the solid (100% in-fill density) sample compared to the non-solid samples. The strength of the samples printed by the normal pattern is 13.9 % higher than the sample produced with concentric profiles. The failure strain of the sample produced with concentric profiles reduces by about 48% compared to samples printed by the normal pattern.