Effects of Identical Parts on a Common Build Plate on the Modal Analysis of SLM Created Metal

The frequency response of parts created with Additive Manufacturing (AM) is a function of not only process parameters, powder quality, but also the geometry of the part. Modal analysis has the potential to evaluate parts by measuring the frequency response which are a function of the material response as well as the geometry. A Frequency Response Function (FRF) serves as a fingerprint of the part which can be validated against the FRF of a destructively tested part. A practical scenario encountered in Selective Laser Melting (SLM) involves multiple parts on a common build plate. Coupling between parts influences the FRF of the parts including shifting the resonant frequencies of individual parts in ways that would correspond to changes in the material response or geometry. This paper investigates the influence of the build plate properties on the coupling phenomena.