Finite element simulations of the experimental tests to explosively weld three layers of Al5056, Al6061 and SS304L tube composites, using various stand-off distances and explosive ratios, are presented in this study. The Williamsburg equations of state and Johnson-Cook constitutive equations were used to describe the behaviors of the explosive and the tubes, respectively. In this paper, the external parameters (dynamic angle and collision velocity) are related to the physical parameters (shear stress and plastic strain). The numerical results showed that very high localized plastic deformation was produced at the bond interface. Moreover, it was found that the shear stress magnitude and signs can provide the necessary criteria for bonding. In addition, the sufficient criterion for bonding was found to be the magnitude of the plastic strain produced at the collision point. The new welding window based on the internal parameters is proposed.