Validation & Verification of IDEA StatiCa
The validation and verification process confirms that the results of the software are correct. Verification is a comparison to an analytical method, most often incorporated in the building code (e.g. AISC 360-16). The verification of CBFEM based on design examples from the building codes is fairly simple and preferable.
Analytical methods in codes are weighed down by simplifications and the results between the code and the CBFEM for complicated connections may vary, especially at boundaries of the range of validity. In that case, a comparison of CBFEM to an advanced model validated by experiments proves that CBFEM is safe even though the resistances are higher than determined by the code.
Validation is a comparison of a numerical model to an experiment. The numerical model is often highly advanced, including material and geometrical nonlinearities. The geometry and material properties are the same as those measured in the experiment. When the results – typically a load-displacement and stress-strain curves – of the numerical model are close to those of the experiment, the numerical model is validated. The material properties of the numerical model are then changed to nominal values, imperfections are increased according to manufacturing tolerances, and several sensitivity studies may be performed by changing parameters, e.g. thickness of plates, yield strength of the material.
Finally, the results of the numerical model are compared to those of CBFEM. The results do not need to coincide perfectly, the CBFEM is typically much simpler, but the CBFEM results must be safe.