UNCERTAINTIES IN NONLINEAR MODELLING OF PUNCHING

: Nonlinear finite element analysis (NLFEA) has become a powerful tool for the prediction of the behavior of concrete structural elements. However, uncertainties that accompany the method, limit its practical application in designing of the new structures to prediction e.g. deflection or other displacement related calculation. Prediction of the bearing capacity is sometimes used in the case of the assessment of existing structures. The broadest application of NLFEA can be found in experimental research because from the tests obtained results it is possible to calibrate the FE models. The paper deals with the influence of some key parameters on the results of NLFEA used for prediction punching capacity of flat slab specimen without shear reinforcement. The dimensions of the finite elements are tested as well as input parameters of used material model for concrete using software Atena.