The research of material nonlinearity in structural analysis is very significant and it has practical importance through application and by upgrading software for numerical analysis. Following that direction, in the framework of this study, numerical models for the 3D frame elements, based on the principles of damage mechanics and theory of plasticity, are defined. Very precise modeling of progressive damage and distributed inelastic behavior in a cross section and along an element for specific types of material is achieved. As a result, highly efficient computational models and programs are developed.