Experimental Investigations of the Influence of Filler Materials on the Dynamic Structural Behavior of a Lattice Structure Manufactured by PBF-LB/M

Abstract

The powder bed fusion of metals using a laser beam (PBF-LB/M) enables the manufacture of geometrically complex structures, which is limited to a certain extent using conventional processes. Lightweight lattice structures produced by PBF-LB/M are suitable for filling hollow component spaces, replacing solid material for mass reduction, or supporting parts during the building process. By infiltrating the cavities of these lattice structures with a second, viscoelastic material, hybrid materials can be created and adapted to a desired application. The current literature mainly deals with the static mechanical properties of unfilled, metallic lattices. However, the second material and its effects on the dynamic properties, such as a change in the eigenfrequency or the damping against unwanted vibrations, have not been investigated experimentally. In this study, a body-centered cubic lattice structure was filled with various polymeric materials to examine their influence on the dynamic structural behavior. The geometrically identical lattices were integrated into a cantilever beam, fabricated from SS316L using PBF-LB/M. The dynamic structural behavior of the beams was compared before and after the filling. Experimental modal analyses with an impact hammer were carried out on the specimens to determine the change in their eigenfrequency, stiffness, and damping ratio from the frequency response function. The results showed that the filling materials have a significant influence on the damping properties of the hybrid material.