PSI - Issue 41

Umberto De Maio et al. / Procedia Structural Integrity 41 (2022) 598–609 Author name / Structural Integrity Procedia 00 (2019) 000–000

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steel bars of the main cracks nucleated at the tension face of the beam, thus avoiding their artificial arrest at the steel/concrete interface.

Fig. 7. (a) Load versus displacement curves; (b) bending moment versus curvature curves.

In Fig. 7a, the load level (service load) adopted for analyzing in-depth the predicted crack patterns is detected. In particular, both crack width and crack spacing of the cracks within the constant bending moment zone are computed and compared with available numerical ((Rimkus et al., 2020)) and experimental ((Gribniak et al., 2016)) results. In particular, Table 4 reports the values of the maximum ( m w ) and average ( a w ) crack width predicted by the numerical models together with the experimental and numerical data. Table 4. Crack width comparison with the present and available results. Maximum crack width m w Average crack width a w Present Model Rimkus Model Experiment Present Model Rimkus Model Experiment 0.102 0.154 0.102 0.068 0.136 0.071 We can note that the proposed model predicts a maximum crack width very close to the experimental one, obtaining a percentage relative deviation, computed by Eq. (6), equal to 0.05% and smaller than that predicted by (Rimkus et al., 2020), equal to 50.98%. A similar result has been obtained for the numerically predicted average crack width. In particular, the percentage relative deviations with respect to the experiment predicted by the numerical models are equal to 4.37% for the proposed model and 91.54% for Rimkus’s model.

num w w 

exp

100

(6)

e





w

exp

Moreover, Table 5 shows the comparison, in terms of both maximum ( m s ) and average ( a s ) crack spacing, between numerical and experimental results. The results obtained by the proposed model are in good agreement with the experiments, providing a percentage relative deviation of the maximum crack spacing, computed similarly to (6) but inserting the corresponding crack spacing values, equal to 2.96% and smaller than that obtained by (Rimkus et al.,