Application of generalized beam theory to semi-rigid plane steel frames

Author(s)

Enio Carlos Mesacasa Júnior

• Document type: Doctoral Thesis
• Press: São Carlos.
• Institution: Universidade de São Paulo (USP). Escola de Engenharia de São Carlos (EESC/SBD)
• Defense date: 2016-09-15

Examining board members

Dinar Reis Zamith Camotim; Cilmar Donizeti Baságlia; Humberto Breves Coda; Alexandre Landesmann; Alex Sander Clemente de Souza

• Advisor: Maximiliano Malite; Dinar Reis Zamith Camotim

Abstract

Steel structural systems are usually associated with an \"indirect approach\", i.e., each component of the respective structure is analysed and verified according to its theoretical individual capacity. Normally, in order to approximate the real behaviour of the structural system, specific support conditions and effective length concepts are used to analyse each structural member separately. However, some important effects are disregarded in this procedure, like the warping transmission at frame joints (due to torsion and/or distortion), or those stemming from localized supports associated with bracing systems, as well as the local/global displacements compatibility of the cross-section walls at the joint region. Additionally, studies considering the above mentioned effects involves rather complicated and time-consuming numerical analyses using shell and/or solid finite elements, and/or expensive experimental investigation. On the other hand, some recent studies revealed a large field for application of the Generalized Beam Theory (GBT) in the context of the stability, first and second order analyses of structural systems, considering, particularly, the effects caused by arbitrary support conditions, different load positions, and the effects caused by connections between members. Nonetheless, all the recent works applying GBT for stability analysis of steel frames are focused on some specific cases of rigid connections, i.e., they assume the full transfer of the generalized displacements between the non-aligned members. Thus, given the well-known fact that the rigidity of connections may lead to considerable changes of the structural behaviour of steel structural systems, this work deals with the development of a solution to incorporate the semi-rigidity of the steel frame connections to the modal parameters of the GBT. Furthermore, given the possibility to expand the connection types analysed by means of GBT, including the most commonly used configurations adopted in practice, it is presented the related new kinematic relations developed, as well as the validation studies carried out in the software ANSYS®. (AU)

• FAPESP's process: 13/12348-1 - Analysis and Design of Steel Structural Systems Using Generalised Beam Theory (GBT)
• Grantee: Enio Carlos Mesacasa Júnior
• Support Opportunities: Scholarships in Brazil - Doctorate