Uncertainties of Crack Width Models

Crack widths for verification of serviceability limit states can be calculated by simplified formulas provided by codes of practice or by numerical analysis based on nonlinear finite element methods. Authors performed a pilot study with the aim to develop a methodology for assessment of model uncertainty involved in the crack width analysis. Experimental data of four beams were used as a reference of real physical evidence for model validation. Two crack models were investigated, namely the model proposed by the fib Model Code 2010 and the numerical model based on fracture mechanics and finite element method. The results indicate that both models tend to underestimate the maximal crack width. The mean crack widths are well simulated by the numerical model.