Statistical approach to the investigation of adjusting the dynamic structural behavior of additively manufactured parts using composite lattice structures: influence of the geometric parameters and the filling with epoxy resin

The integration of lattice structures into parts using powder bed fusion of metals using a laser beam (PBF-LB/M) allows tailoring mechanical properties by adjusting their geometric parameters. A composite material created by filling the voids in the lattice structures with a second, viscoelastic material offers promising dynamic properties. However, understanding the relationship between the lattice geometry and the resulting dynamic mechanical behavior is essential for designing composite materials and applying them to industrial components, such as boring bars. This study investigated the dynamic structural behavior of various strut- and wall-based lattice structures filled with epoxy resin. Lattice structures were integrated into IN718 beams manufactured by PBF-LB/M. Experimental modal analyses were conducted to evaluate the changes in the eigenfrequency, the dynamic compliance, and the damping ratio before and after the filling. Microscopic and cross-sectional analyses supported examinations. The results showed that the unit cell size and the volume fraction significantly influence the infiltration. In addition, the eigenfrequency and the dynamic compliance can be effectively adjusted by changing the volume fraction. In particular, the epoxy resin filling had a large effect on the damping ratio and increased it by a factor of up to 3.6 for the body-centered cubic cell. Among all the studied lattice types, the diamond TPMS structure had the highest eigenfrequency and the lowest dynamic compliance. From the results of the statistical evaluation, recommendations of action for the design of composite lattice structures were derived.