Damping Performance Hysteresis Modeling and Prediction of Particle Damper Infused AM Components

With recent developments in additive manufacturing (AM) serving as an enabling technology, a novel application of particle damping has been applied to beam specimens as well as blade and engine relevant hardware through the use of laser powder bed fusion (LPBF). Using LPBF, work in the literature has demonstrated by intentionally printing geometries with cavities, allowing unfused powder to remain, acts as an inherent particle damper and shown to attenuate dynamically excited amplitude and therefore stress in the component by up to 90% when compared to fully fused parts subjected to the same base excitation. However, previous applications of this technology have been applied to basic geometries of beams and plates. In this work, the damping performance of a representative aerodynamic instrumentation rake. Three configurations of the rakes are printed to include a “fully fused”, 0.254mm, and 0.58mm pocket thicknesses. The specimens are first scanned and three dimensionally reconstructed to compare the nominal CAD drawing to as-printed and received geometry. Then, CT scans were performed and the unfused powder volume estimated and compared. Vibrational testing is performed to excite the specimen in a 2^nd bend mode. Amplification and Q factor, or quality factors, are compared to evaluate the damping performance amongst the three rake configurations.