Finite element analysis is extensively employed to predict the structural response of mechanical components so reducing costs of experimental programs. However, among other aspects, the accuracy of the input material parameters in the finite element modeling strongly determines the simulation accuracy. The aim of this study is to evaluate the material constitutive parameters, considering an elasto plastic material model with strain rate sensitivity and failure and by using an inverse methodology. The evaluated material was a mild steel sheet used in scale models of naval structures. Quasi static and dynamic tests were performed and the so obtained material parameters were corroborated through numerical modelings of notched and shear specimens tests. Finally, a discussion about the evaluation of strain rate sensitivity model and failure criteria parameters is also presented.