Optimization of the material parameters of the continuous surface cap model for concrete

Modeling the nonlinear behavior of concrete within the problems of continuum mechanics for designing protective and military structures is now undoubtedly the subject of effort of staff of many scientific institutes. Striving for modeling real nonlinear behavior of concrete through sophisticated material models implemented in an even more sophisticated computing systems based mainly on the finite element method, however, brings with it certain problems. The main problem is especially a lack of knowledge of material constants (parameters) that must be defined to ensure proper function of a particular model. One possibility, which today enables the mentioned problem successfully solved, is the use of optimization procedures in order to find the correct values of the material parameters. Parameter optimization goes hand in hand with experimental investigation of concrete structures, while it trying to find parameter values of used material model of concrete so that the resulting data obtained from the numerical simulation will best approximate the experimental data. This paper deals with parameter optimization of nonlinear material model of concrete, which is implemented in a computing system LS-Dyna, with the use of optimization procedures and experimental data obtained from the direct tensile tests performed on specific concrete test specimens.