Insights on the Dynamical Responses of Additively Manufactured Systems

Structures and parts are increasingly being fabricated using Additive Manufacturing (AM) due to low material waste, ability to quickly generate prototypes, and potential to create complex geometries that would otherwise be difficult or expensive to manufacture. While there are many benefits to using AM processes, the dynamic behavior of the structure is dependent upon the orientation of the construction. This requires investigation of orthotropic materials which have varying material properties in each of the primary Cartesian axes. Some materials, such as the common 3D printing filament Polylactic Acid (PLA), behave orthotropically. Orthotropic materials have often been represented as isotropic materials to simplify numerical models. While such an assumption may be valid in some cases, this study seeks to characterize PLA beams with a tip mass. Experimental PLA beams are printed in the same orientation and have the same external geometry, but the angle of the filament measured from the major axis of the beam varies. The dynamical characteristics are acquired using free and random vibration experiments. The results show that the angle of filament has a significant effect on the damping ratio and natural frequencies of the system.