抄録
The point defect dependence of the longitudinal wave velocity indicates the elastic stiffness degradation due to plastic deformation damage which is closely related to the deformation instability mechanism. Therefore, in this paper FEM numerical simulations regarding to the contour line of amount of point defects estimated by the calculation of the intersected cross slip among dislocations under several proportional loading paths are performed and compared with the experimental results of necking onset strains in aluminum specimens measured by laser speckle method. The good agreement between the simulated and experimental results regarding the onset of the deformation instability suggests that the proposed algorithm to calculate the amount of point defects caused by intersected cross slip among dislocations has ability to be unified criterion for both localized and diffused neckings.
