V.N.Oliynik Acoustical properties of a layer on rigid foundation underlying local vibrational excitation |
Acoustic bulletin, Vol. 5 ¹ 1, (2002) |
| A problem on local vibrational excitation of a plane-parallel layer of acoustical medium, which is situated on absolutely rigid foundation is solved by the method of partial domains. A circular piston attached to a free surface of the layer and harmonically oscillating with a given normal velocity was considered as a source of vibration. Such system was offered as the mechanical model of a contact interaction between the surface soft tissues of human thorax and a kinematic sensor, like the one used in medicine and biophysical researches. At the same time the possibility of propagation of the transverse waves in the tissues was ignored. When conducting the numerical analysis the main attention was paid to calculating the frequency dependencies of piston's radiation impedance in range corresponding to audible sound. This characteristic is necessary to be known to forecast the distortions introduced by presence of a sensor in vibration of the thorax in a contact zone. Obtained results give evidence that when neglecting the possibility of propagation of the transverse waves it is impossible to simulate properly a contact interaction between the vibrator (sensor) and the biotissue. |
|
KEY WORDS: a plane-parallel layer, acoustic medium, local vibroexcitation, impedance |
| TEXT LANGUAGE: Russian |