Kinetics and morphology of Lüders deformation in specimens with homogeneous structure and with a weld joint

Abstract The presented work focus on the investigation of the elastic-plastic transition in materials with a sharp yield point occurring through the formation and propagation of Luders band. It has been found that the band nucleation and propagation rates in specimens with homogeneous structure are considerably different. The velocities of Luders band fronts are correlated so that the total velocity of all moving fronts at any point of deformation is a constant value. As the rate of deformation increases, the Luders band front velocity increases nonlinearly. If the material contains zones with high structural and phase inhomogeneity, Luders bands nucleate along the boundaries of these zones. The kinetics and morphology of the Luders band fronts within these zones are considerably different from those observed in other areas of specimen. It has also been found that the Luders band front stops upon reaching the boundaries of the zones with structural and phase inhomogeneity. In this case, the front acts as a source of both individual and multiple bands.