an investigation into free flexural vibration of defective 3d-printed pla beams with embedded delamination

Polylactic acid (pla), is a versatile, thermoplastic, biodegradable, and one of the most eco-friendly polymers widely used in 3d printing and manufacturing of elements used in healthcare, textile, packaging, bio-medical devices, as well as low-cost bio-composite materials used in aerospace structural components. therefore, the characterization of the filaments and the printed parts is essential for determining quality, controlling manufacturing processes, and making accurate model predictions of procedure and product performance. in the present study, the flexural vibration analysis of a defective 3d-printed pla beam will be presented. experimental and fem-based numerical free vibration analyses of a cantilever beam specimen, with embedded delamination, are presented. the defect is a single, symmetric, through-the-width, centrally located, delamination, covering one-third of the beam’s length. the average experimental frequency values are calculated based on three different trials, conducted to ensure the accuracy of the obtained results. numerical results, including fundamental flexural frequencies and corresponding mode shapes, obtained through simulations carried out using finite element analysis (fea) software are also reported and discussed. the comparison is made between the frequency results obtained from two numerical (fem) models and the experimental ones. the first fem model assumed a uniform delamination zone, whereas the second one was created considering the nonuniformity of the defective region. it is observed that the numerical natural frequency obtained from the latter model corresponds better with the experimental values.