研究論文
高速フーリエ変換法を用いたセレーションの評価
2004 年 54 巻 2 号 p. 51-56
詳細
2004 年 54 巻 2 号 p. 51-56
Fast Fourier Transform (FFT) method was applied in order to evaluate a repeated load drop (serration) observed in the load-time curves in the tensile test. 5083 aluminum alloy plates were tested in tension at temperatures between 203 K and 333 K using an Instron type tensile test machine. Changes in repeated load drops with the deformation temperature were characterized by a conventional method (mean amplitude ΔLm and number N of load drops) and FFT method (maximum amplitude Cmax and peak frequency fp derived from the Fourier spectrum). Cmax and fp were compared with ΔLm and N, respectively. The comparison showed the reasonable agreement between fp and N, as well as that of Cmax and ΔLm. In evaluation of the serration using FFT method, there was no artificial reading error and reliable analysis could be carried out in a short time. Therefore it suggests that FFT method is suitable for the investigation of the serration.
