STRESS-STRAIN STATE OF THE PLATE AFTER IMPACT INTERACTION WITH AN ELECTRODE OF DIFFERENT SHAPES

The influence of the shape of the electrode-indentor (cylindrical and parallelepiped with a rounded shape of the contact surface) on the stress-strain state of the plate made of aluminum alloy AMg6 after their impact interaction at a speed of 10m/s was evaluated by the method of numerical modeling. Features of creation and use of developed mathematical models are described. The distribution along the thickness of the plate of the values of the main parameters and components of the stress-strain state, as well as the dimensions and shape of the zone of plastic deformations, the location of zones with compressive and tensile stresses, the depth and width of the dent in the plate, were determined. In particular, it was established that the interaction of an axisymmetric striker with a plate compared to the interaction with a flat striker leads to an increase in the duration of their contact by 20% and, as a result, the dimensions of the dent in the plate increase: the depth by 21%, and the width by 23 %. It was also established that such an interaction leads to an increase in the size of the plastic deformation zone in the plate by almost two times, with its exit beyond the overall dimensions of the striker with a simultaneous transformation of its shape from trapezoidal to rectangular; occurrence in the plate of almost 2 times higher maximum values of effective plastic deformations, which are formed mainly on the contact surface.As a result of the simulation, it was shown that the dynamic processing of a plate with a cylindrical (axisymmetric) indentor with a rounded head, in comparison with a flat elongated shape, leads to the formation of an almost uniform distribution of both components of the stress state (axial and radial) as compressive stresses, which make it possible to combat residual stresses in the material, such as those arising after welding, and this fight against the axial stress component will be less effective (almost 4 times) compared to the fight against the radial component.