A Numerical Investigation Into the Natural Frequency Analysis of Delaminated 3D-Printed PLA Beams Including Contact

This report includes the results of experimental and numerical modal analyses, performed to determine the flexural fundamental natural frequency of the 3D-printed PLA beam with delamination. Two types of 3D-printed samples, having 0.1mm and 0.5mm delamination thicknesses, are studied. The results of numerical modal analysis are compared and verified against those obtained experimentally. The Finite Element Analysis (FEA), carried out numerically using ABAQUS software, was performed for six cases. For a sample with 0.1mm delamination thickness, two analyses were performed by first excluding and then in the presence of contact/friction in the delamination zone. Another specimen, with a 0.5mm-thick delamination region, was also investigated, where two sets of studies were conducted. The delamination region was first modeled as uniform and was then refined to include the geometric non-uniformity resulting from the 3D-printing process. The latter model exhibits a more realistic representation of the real sample. In each case, two numerical modal analyses were performed, without and with friction contact in the delaminated segment. At the end, a comparison is made between all these models to show the effect of friction, delamination thickness, as well as uniform vs realistic modeling of the delamination, on the bending fundamental frequency of the PLA delaminated beam.