Determinação de propriedades elásticas e mecânicas de chapas de aço utilizando medidas ultrassônicas e análise computacional

Abstract

This research report presents a proposal for estimating the elastic and mechanical properties of steel sheets investigated through the propagation of acoustic and ultrasonic waves, associated with computational analysis. For this, an electronic system that emits and receives ultrasonic waves generated in the 2 MHz range was used, and mathematical models were applied to determine the elastic properties of two different steel sheets. The results found for the moduli of elasticity, shear and compressibility, as well as the limit of tensile strength, yield stress and Brinell hardness, were estimated based on the values of the ultrasonic wave propagation speeds and plate density. To investigate the propagation of acoustic waves on the surface of the samples, a steel sphere was used in conjunction with software to perform the impact acoustic wave test. The data obtained were analyzed using the Origin 7.0 program with the aim of analyzing the behavior of the average acoustic signal in the samples. The results of this research demonstrated the viability of the water immersion transmission method, obtaining values of elastic and mechanical properties very close to those reported in the literature. Furthermore, the results obtained indicated a relationship between mechanical properties and a characteristic frequency spectrum of the samples, derived from the decomposition of the temporal function of the acoustic signal in the frequency domain. For this, the Fast Fourier Transform (FFT) method was used, where the frequency spectrum of the acoustic signal was generated by the Matlab fft(x) function algorithm, which calculated the FFT from the acoustic signal converted into a vector of one-dimensional data.