VIBRATORY SYSTEM IDENTIFICATION OF 3D PRINTED CANTILEVER

Although 3D printing has become a widespread method of fabrication, the vibratory properties of thermoplastic composites are poorly understood. This is, in part, due to the anisotropies introduced by the 3D printing process, the composite materials used, and the geometry. In this study, an attempt has been made to characterize the vibratory response of a 3D printed thermoplastic cantilever, in order to determine the damping ratio and natural frequency. The cantilevered beams were 3D printed, with a range of varied parameters. These parameters include the inclusion and exclusion of continuous carbon fiber reinforcement, as well as the three orthogonal build directions. Impact tests and frequency sweeps were used to gain information about the vibratory response of these cantilevers. This information was used to model the effects of the carbon fiber and anisotropy introduced by the different build parameters. During the experiments, a highspeed camera was used to record the response of the cantilevers. These videos were then post-processed with image analysis tools to quantify the response. Then, a point near the tip of the cantilever was used as the time-dependent variable for a reduced order model. By proceeding in this described method, the damping ratio and natural frequency of the system may be written as a function of the build parameters.