Modeling of nonlinear behavior of steel beam to column semi-rigid connections with 3-d solid finite elements

Azap, Nurettin Murat
In steel structural systems, beam to column connections are usually assumed either rigid or pinned in practice. In reality rigid connections have some flexibility and shear connections have some rigidity incorporated in their real behavior with significant nonlinearity included, as well; thus this behavior results into the categorization of some connections as semi-rigid. Beam to column connection regions contain one or more of the following components: angles, plates, welds, and bolts. Understanding the physical actions occurring between all these parts is crucial. In this regards the development and use of numerical tools and also further experimental studies trying to identify the monotonic and cyclic behavior of semi-rigid connections have gained significant attention. Detailed modeling and analysis of structural members by using advanced finite element programs is very common nowadays. Conducting experiments may supplement verification of numerical simulations; however experimental works may not be practical in some cases. Despite the advance in computer technology, for the modeling of the complex interaction of geometric and material nonlinearities in steel semi-rigid connections the use of regular computers may not always suffice in terms of computer power and large amounts of analysis time is still needed. In this thesis 3-D finite element modeling and analysis of semi-rigid connections is undertaken, where for this purpose a special type of bolted beam to column connection is chosen due to its truly semi-rigid characteristic. Previous experiments conducted on this connection type in the last three decades are considered for the numerical study undertaken in this thesis. Results obtained from numerical simulations are compared with experimental data and the reliability of 3-D modeling of connections with the use of advanced nonlinear finite element programs is assessed. In order to model bolted beam to column connections accurately in a numerical simulation for all connection topologies, detailed understanding of the nonlinearities that need to be taken into account during the use of finite element software should be well known. In this regards, special attention has been given in this thesis for the presentation of how a bolted beam to column connection region shall be modeled, as well.
Citation Formats
N. M. Azap, “Modeling of nonlinear behavior of steel beam to column semi-rigid connections with 3-d solid finite elements,” M.S. - Master of Science, Middle East Technical University, 2013.