For the modeling and usual analysis of mechanical structures it is considered that the whole structure and its components accomplish one of the fundamental conditions of strength of materials - the condition of continuity and homogeneity. This paper presents some modeling techniques useful for the optimization of the numerical models in order to improve the structural response for impact applications. As some parts have to be damaged a material model capable of material failure must be used. The differences between the results obtained using a model without failure and a model with failure compared to the experiments were discussed. The second procedure is regarding the random distribution of the thickness properties of the elements for a selected area within the user specified tolerance. Procedures implemented in custom written code and the algorithms presented for the random distribution were presented