The Evaluation of the Previous Models Used to Study the Web Post-buckling

The number of suggested and modified theories for web post-buckling behavior shows that this is one of the topics receiving much attention in civil engineering. However, the controversy related to the elusive behavior of web post-buckling is going on. The present study using an updated data set from 27 previous experimental shear tests and the current FEA results is to evaluate Basler's model which represents classical theories and Lee and Yoo's model which represents recent researches. This research indicates that none of the investigated models provides the accurate prediction of ultimate shear strength in the whole range of practical parameters, they tend to overestimate or underestimate the ultimate shear strength of the girder depending on the aspect ratio of the web panel. Besides, the current FEA results reveal that the in-plane tension field (classical tension field) as in Basler's theory is not the unique source in web post-buckling reserve and does not characterize the actual behavior of web post-buckling. The reason is that the stresses on two surfaces of the web panel dominate the post-buckling reserve.