SMALL PUNCH TESTING AND ITS NUMERICAL SIMULATIONS UNDER CONSTANT DEFLECTION FORCE CONDITIONS

A comparison of results of small punch tests on miniaturized discs under a constant force with their simulation by means of FEM is presented. A heat-resistant steel of type CSN 41 5313 (EN 10CrMo9-10) was selected for our investigations. The small punch tests as well as the necessary conventional creep tests on massive specimens were performed at 873 K. For simulations, the Norton power-law and the exponential relationships were applied in the FEM model of the SPT arrangement. Parameters of both relationships were derived from stress dependences of minimum creep rate obtained from the conventional creep tests. While at higher loads the Norton power-law yields results more comparable with those obtained from experiments, at lower loads the exponential relationship gives better results. The investigation also confirms the simple relation between stress in conventional tests and force in small punch tests resulting in identical time to fracture of both types of tests.