Research into the effect of technological imperfections of meniscus liners on explosive formation dynamics of high-speed rod elements

The paper presents the research into the effect of liners thickness variation in circumferential direction on kinematic characteristics and geometrical parameters of the generated high-speed elements. The liners thickness variation is presented as a sum of elementary trigonometric harmonics. The analysis is based on a threedimensional numerical simulation of explosive loading of the liners coatings in Lagrangian coordinates. The authors implement a method for simulation of small-amplitude harmonic components of the liners thickness variation based on the forced minor distortion of the axisymmetric mesh. The article discloses a technique projecting the contour of a high-speed element onto coordinate planes and estimating position of its axis of symmetry. The technique is used to estimate the shape of the high-speed elements as well as their transverse and angular velocities. With the help of this technique, the authors calculate the most important kinematic characteristic, that is an angular velocity, which the high-speed elements attain due to variation in the liners thickness. The calculations made with due account for simultaneous presence of several harmonics in the structure of the liners thickness variation showed that the harmonics superposition can be considered as one of the reasons for the high-speed elements asymmetry in both radial and axial directions as well as for their destruction.

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