Liquid Jet Impact on the Surface of Metal Alloys

Resumo

A mathematical model and computational results on dynamics of an elastic-plastic body under impact of a high-velocity liquid jet with a hemispherical end are presented. The body is simulated by an isotropic semi-space; the von Mises condition is used to describe its plastic states. Stresses arising in the surface layer of the body and the deformations of its surface are studied, depending on the material of the body. The study is carried out in the axisymmetric problem statement using a UNO-modification of the Godunov method, which is of the second-order of accuracy both in space and time. The loaded area of the body surface is a circle the radius of which quickly increases from zero. The pressure in the loaded area is spatially and temporally non-uniform. Bodies of three metal alloys are considered, namely, of aluminum, Monel 400, and steel. The loading of the body surface in all three cases corresponds to impact of a water jet at a velocity of 250 m/s. It is shown that under such impact, short-term yield zones arise in the surface layer of the bodies, and a nanoscale pit appears on the body surface in the center part of the impact area. The influence of the body material on the size and configuration of the yield zones as well as the pit profile and its maximum depth is presented.