Novel Approach for Simultaneous Measurement of Elastic Properties and Attenuation Coefficients of ABS Polymers Using Ultrasonic Scattering

In this paper, we present an innovative, non-destructive method for the simultaneous evaluation of the elastic properties and attenuation coefficients of polymeric filaments utilized in the Fused Deposition Modeling (FDM) additive manufacturing process. This method is grounded in the theory of acoustic wave scattering, where polymer filaments are immersed in water and subjected to acoustic waves. The scattered waves carry detailed and comprehensive information about the elastic properties and attenuation coefficients of the filaments. To extract this information, we employ an inverse method that involves comparing the resonance frequencies observed in the scattered signals with the predictions made by a theoretical model. Our data analysis process integrates advanced techniques, including deconvolution and genetic algorithms, which enable the precise and accurate measurement of critical parameters such as longitudinal and transverse velocities, density, and both longitudinal and transverse attenuation coefficients in a single experiment. The findings from our experiments reveal that, for the ABS filaments studied, the longitudinal and transverse velocities are 2280 m/s and 956 m/s, respectively, while the longitudinal and transverse attenuation coefficients are measured at 0.012ka and 0.024ka Nepers, respectively, with a filament density of 1006 kg/m³. These experimental results were validated through comparison with ultrasonic pulse-echo tests performed on ABS rods with a diameter of 25 mm, confirming the accuracy of our method. Specifically, the errors in measuring longitudinal and transverse velocities were found to be less than 2.5% and 13%, respectively, while the density measurement exhibited an impressively low error margin of just 0.2%. Furthermore, the error in the longitudinal attenuation coefficient at a frequency of 0.5 MHz was approximately 6%, and the error in the transverse attenuation coefficient at a frequency of 5 MHz was about 12%. This research not only demonstrates the accuracy and reliability of our proposed method but also contributes significantly to a deeper understanding of the properties and behavior of polymers used in additive manufacturing processes