Dynamic plastic response of double-layered circular metallic plates due to localized impulsive loading

摘要

In this paper, the dynamic plastic response of double-layered circular metallic plates subjected to localized impulsive loading was investigated both numerically and empirically. A numerical model was developed in commercial finite element code ABAQUS/Explicit via a user user-defined FORTRAN subroutine in conjunction with the Johnson-Cook thermo-viscoplasticity and damage models. The numerical results were validated with the available experimental results. Next, rigorous parametric studies were conducted on double-layered plates made of Weldox 460E, Aluminum 1100-H12 and a combination of these materials with copper plates for the impulse range of 10-110 N.s. Finally, dimensional analysis of the parametric study was performed and new empirical design formulas were derived for prediction of central deflections of back and front layers based on the suggested dimensionless numbers. The numbers considered the effect of the structural geometry, the inertia of applied dynamic load, the material resistance ability to the plastic deformation, the strain rate sensitivity of the material, and the load ratio both for front and back layers. The comparison between parametric study results and proposed empirical expressions illustrated that the derived equations provided quite reliable and accurate predictions of the central deflections of back and front layers when the deflections changed ranging from 11.4 mm to 62.8 mm.