Crack detection in reinforced concrete beams under various loadings using the modal strain energy method and confusion matrix model

Abstract

In this study, a damage detection method for reinforced concrete (RC) beams using the modal strain energy (MSE) method combined with a confusion matrix model is proposed. This method is used for identifying the crack zone position and length of RC beams under various loadings. The beam is modelled by ANSYS APDL software. To prove the finite element model’s validity, the static properties of the model are compared with experimental data and theoretical calculation. From the natural frequencies and mode shapes at different load levels, a damage index is calculated using the MSE method. The crack zone is detected by comparing the damage index with a proposed damage threshold. Then, the damage detection method’s accuracy is evaluated by the confusion matrix model. Finally, the results from this study show that the proposed method can detect the position and length of the crack zone in the RC beam under various loadings with high accuracy.