Finite-Element Modeling of Beams under Concentrated Loading

Abstract

A numerical study of aluminum and steel beams subjected to concentrated loading is performed and compared with experimental data from the literature. The modeled test specimen referred to simply supported beams where the concentrated loading is applied either at the midspan or at the end support, and the influence of varying bending moment and beam overhang is investigated. The modeled cross sections cover a wide range of web geometries and flange stiffnesses, and loading through both circular bars and rectangular bars are included. The contact between the beam specimen and the loading bars is modeled with a contact algorithm, and the problem is solved by an explicit code. The correlation between the experimental and numerical results is quite good, especially for the ultimate capacity where the difference between predictions and tests is not prominent when compared to the scatter in the test results. The error in the ultimate capacity from finite-element simulations is within 14% of the measured value, and for the web deformation, simulations can predict the main effects that are obtained from the tests. The results show that small elements are necessary for predicting the correct mode of failure, and the development of the local instability depends on the mass scaling and assumed imperfection field. Furthermore, brick elements seem appropriate for including the effect of hydrostatic pressure, and the adopted fracture model seems useful for predicting the crack development that was observed for some specimens.