Establishing the fiber bridging law by an inverse analysis approach

A method for establishing the relationship between stress and crack face opening for steel fiber–reinforced concrete (SFRC) beams under three-point loading was proposed using inverse analysis. The relationships were set up in two parts: Fracture mechanics theory was used before the hinge formation, followed by a classical mechanics of materials approach after the hinge was formed. This methodology did not incorporate any assumptions and was validated by the construction of experimental load versus crack mouth opening–displacement (CMOD) curves and by predicting the experimental load versus CMOD relationship for independent flexural tests on beams of different sizes. The proposed method can simulate and predict the complete flexural performance of SFRC beams under three-point bending.