De Lauro Enza, De Martino Salvatore, Esposito Enrico, Falanga Mariarosaria, Primo Tomasini Enrico
Physics Department, Salerno University, S. Allende Street, 84081 Baronissi, Salerno, Italy.
J Acoust Soc Am. 2007 Oct;122(4):2413-24. doi: 10.1121/1.2772225.
Several experiments have been performed to investigate the mechanical vibrations associated with an organ pipe. The measurements have been made by using laser Doppler vibrometry, a well-known not-invasive optical measurement technique that is very widely used in structural dynamics. The recorded signals are analyzed by using a well-established decomposition method in time domain, i.e., independent component analysis. Asymptotic dynamics methods to recognize low-dimensional dynamic system associated with this wave field is then considered. The full-toned recorded signals appear decomposed into three independent components. The independent components are nonlinear due to the fractal dimension of the attractor. These results for the mechanic vibrational field are compared with those of the acoustic one. It is interesting to note that the two fields have many common characteristics. Finally, a low-dimensional dynamic system that reproduces the main characteristics of the mechanical wave field in the time and frequency domains is introduced.
已经进行了几项实验来研究与风琴管相关的机械振动。测量是通过使用激光多普勒振动测量法进行的，这是一种在结构动力学中广泛使用的著名的非侵入性光学测量技术。通过使用时域中一种成熟的分解方法，即独立成分分析，对记录的信号进行分析。然后考虑用渐近动力学方法来识别与该波场相关的低维动态系统。记录的全音信号似乎分解为三个独立成分。由于吸引子的分形维数，这些独立成分是非线性的。将机械振动场的这些结果与声场的结果进行了比较。值得注意的是，这两个场有许多共同特征。最后，引入了一个在时域和频域中再现机械波场主要特征的低维动态系统。
