Finite element theoretical and experimental study on the dynamic characteristics of material extrusion thin plates

Abstract

Material extrusion (ME), one of the most rapidly developing additive manufacturing techniques, has been widely used in the field of aerospace, medical, industrial design, and so on. Since the working environment is increasingly complex, it is urgent to study the ME products' dynamic performances to determine their reliability. In this article, a finite element theoretical model of ME thin plate was established with the porosity defect taken into account. A modal test system was set up and the multiple-input single-output method was used to obtain the measured data. The scanning electron microscopy (SEM) analysis on the samples confirmed that the dynamic characteristic was improved as the extrusion temperature increased. In addition, the sensitivity analysis was carried out on the model to predict how the samples' elastic modulus, Poisson's ratio, and density affect their dynamic characteristics. The results show that the proposed model is reliable to give accurate predictions on the dynamic characteristics of ME thin plates. With the increase of extrusion temperature, the samples' natural frequency will increase, and the vibration response will decrease. The sensitivity analysis indicates that increasing elastic modulus or Poisson's ratio can increase the natural frequency of ME thin plate but decrease the vibration response. While increasing the density will decrease both the natural frequency and vibration response.