Abstract: The variation in the carter radius and the velocity of rubber layer are derived via a Bernoulli’s equation. The performance of the rubber composite armor against the shaped charge jet is investigated, and an engineering model for the deformation of armor plates is presented based on rheological theories. By conducting 3D numerical simulations and X-ray experiments, the deformations of the rubber composite armor are measured to verify the engineering model. The results indicate that the deformation of armor is relevant to the volume flow rate, original pressure, and material characteristics. A comparison between theoretical and numerical results and experimental data demonstrates an improved agreement at distances between the jet axis and center of armor of approximately 20mm to 80mm. Therefore, the model presented in this paper accurately calculates the deformation of armor.