###### Abstract
UT testing can be applied to objects with complex geometries, but the surface roughness significantly influences the signal detection and its quality. In cases involving rough surfaces, liquid couplants are used to improve the test results [28; 31]. UT also demonstrates good performance in detecting cracks [32]. This NDE method is cost effective, simple to use, and capable of detecting internal defects within the printed material [27; 31; 32]. There are other methods of determining material parameters [33; 34]. For example, elastic parameters could be obtained from 3- and 4-point bending tests. However, these tests typically proceed further to the destructive phase. To enable the assessment of the future assessment of the material in real time, the ultrasonic method was chosen. Several studies were conducted on the effect of parameters of the printing process on the mechanical properties of the plastic parts. [PERSON] et al. [35] chose infill density, perimeters, and nozzle angle as the printing variables. [PERSON] et al. [36], in their investigation, changed the following parameters: perimeters, solid layers, fill density, fill pattern, solid fill pattern, and extrusion multiplier. In the study of [PERSON] et al. [37], variable raster angles and infill densities were used. [PERSON] et al. [38] explored the influence of layer thickness, infill density and pattern, printing speed, build orientation, and raster angle on the mechanical properties of the FDM-printed parts. In general, researchers make their own selection of printing parameters based on the interest of the study and their vision. Therefore, in this work, nozzle speed, printing speed, and temperature were chosen as the variable parameters as we believe that changes in these parameters could result in different properties of the final material. The use of NDE in the post-printing assessment of material quality is well established. In this work, the potential of an ultrasonic NDE method in evaluating the elastic properties of PLA printed with various parameters was explored. The effect of various variables in the printing process on the resultant material properties was studied. Such an opportunity may enable a real-time adjustment of printing parameters to enable certain material properties by utilizing NDE information in conjunction with the printer's control and hardware settings. A multi-dimensional response surface that links various process settings to the measured elastic material properties could be utilized as a foundation for NDE-enabled real-time decision-making to obtain the desired outcome from the printing process. For this purpose, a database of the dependency of the elastic properties (including Young's modulus, shear modulus, and Poisson's ratio) of the PLA material on the parameters of the printing process such as printing temperature, printing speed, and layer height was established. PLA is one of the widely used filaments in additive manufacturing. Unlike other printing materials, e.g., metals, the printing controls and temperatures for PLA are not as demanding, making it a convenient choice for laboratory testing. Furthermore, PLA is a rather challenging material for ultrasonic testing (UT) due to its high attenuation since less attenuative materials are likely to provide broader opportunities for real-time ultrasonic NDE. The findings from this research offer valuable insights into how printing process parameters affect the elastic properties of the printed samples, benefiting a broad spectrum of users working with PLA materials.