Analyzing the effect of notch geometry on the impact strength of 3D-printed specimens

Abstract

Additive manufacturing (AM) using 3D printing techniques such as fused deposition modeling (FDM) has now found much attention, not only in prototyping but also in industrial production. Indeed, the 3D-printed components are now widely used as structural elements in many applications such as biomechanical engineering (dentistry, orthopedics, bio implants, etc.) and therefore, full understanding of their strength, load carrying capacity, improving the mechanical behaviors, and manufacturing process is an important issue. Charpy impact experiments offer information on the strength of a material to sudden failure where a sharp stress raiser or notch is present. In addition to providing information not available from any other simple mechanical experiments, the impact resistance tests are quick and inexpensive, so they are often used. In this research, impact strength experiments were conducted at room temperatures on rectangular samples containing three different notches including V-notch, U-notch, and Keyhole-notch to determine impact resistance of the 3D-printed polylactic acid (PLA) components. The capability of multiple comparison tests for analysis of variance like ANOVA, Tukey, and Fisher methods for prediction of impact resistance in the tested specimens were also investigated. The samples containing Keyhole notch showed highest Charpy impact resistance. In contrary, V-notched sample provided the lowest impact energy. All the employed statistical analyses reveal that the notch type has meaningful influence on the impact energy of 3D-printed parts.