|
ИСТИНА |
Войти в систему Регистрация |
ИПМех РАН |
||
Nonlinear elastic properties of the interface solid - granular unconsolidated mediaтезисы доклада
- Авторы: Shirgina N., Kokshaiskiy A., Korobov A.
- Сборник: IUS 2015 Abstract book
- Тезисы
- Год издания: 2015
- Первая страница: 565
- Последняя страница: 565
- Аннотация: The paper presents the results of experimental investigations of nonlinear elastic properties of the interface between solid and granular unconsolidated media. The experiments were performed in a system consisting of a flat metal plate and unconsolidated granular medium. Unconsolidated granular medium modeled by a layer of steel balls 2 mm in diameter. Study of nonlinear elastic properties of the interface were carried out using surface acoustic waves (SAW). SAW were excited and detected on the surface of a metal plate by wedge transducers at frequencies of 1.25 MHz and 2.5 MHz. Experimental studies have been performed on automated ultrasonic complex RITEC RPR-5000. We investigated the effect of the static pressure applied to the interface granular medium - solid, and the effect of amplitude of the probe SAW (frequency of 1.25 MHz) on the velocity of SAW. SAW velocity increases at a fixed mechanical pressure when the amplitude of SAW increases. SAW velocity increases when its pressure decreases at fixed amplitude. SAW velocity change depending on the amplitude and the static pressure were nonlinear. For a fixed value of the amplitude of the probing SAW on a frequency of 1.25 MHz, we studied the effect of pressure on the efficiency of second harmonic generation of SAW on the frequency 2.5 MHz. According to results of experimental measurements of the amplitudes of the first and second harmonics of SAW at the interface between granular medium and solid, we calculated nonlinear elastic parameters of the second order of SAW depending on the external pressure applied to the interface. Nonlinear parameter has features that were caused by changes in the contact elastic nonlinearity associated with changes in the external pressure applied to the interface. The obtained results were analyzed on the basis of the theory of contact acoustic nonlinearity. This study was supported by the Russian Science Foundation (project №14-22-00042).
- Добавил в систему: Ширгина Наталья Витальевна