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Особая структура двух-зонной упруго-пластической ударной волны в кристалле меди в направлении [100] (Peculiar structure of two-zone elastic-plastic single shock wave in Copper in [100] direction)
Докладчик(и): Василий Жаховский, Наиль Иногамов, Сергей Анисимов (ВНИИА, Росатом) Дата, время проведения: 20 ноября 2014 г. (четверг) 11:00 часов Адрес: Конференц-зал КК (ул. Красноказарменная, 17-а). Abstract: Different structures of steady shock waves propagating in single crystals of copper and nickel oriented in [100] direction are studied with the use of molecular dynamics simulation in Moving Window coordinate system associated with shock-wave front. Because the [100] elastic branch of P-V shock Hugoniot goes closely to the plastic branch of Hugoniot in all fcc crystals, an elastic zone of two-zone single shock wave is not so well pronounced in a pressure profile across the shock front as in shock waves propagating in directions [110] and [111]. It is found that a two-zone elastic-plastic wave in nickel has a normal structure, where pressure in the elastic zone is always lower than in the following plastic shock front. But in copper the elastic zone may have a pressure exceeding a pressure in the followed plastic zone, which results in drop of pressure in the plastic front where the elastic-plastic transformation takes place. The unloading plastic front moves with the same speed as a leading elastic shock wave. Thus, such an unusual shock wave has a structure which is similar to that in a detonation wave. It is shown that phenomenon takes place in a specific range of compressions in Cu, where the elastic branch of P-V shock Hugoniot goes below the plastic branch of Hugoniot. |