Mechanical modeling for predicting the axial restraint forces and rotations of steel top and seat angle connections at elevated temperatures
Journal of Structural Fire Engineering
ISSN: 2040-2317
Article publication date: 22 June 2017
Issue publication date: 16 August 2017
Abstract
Purpose
This paper aims at developing a mechanical-based model for predicting the thermally induced axial forces and rotation of steel top and seat angles connections with and without web angles subjected to elevated temperatures due to fire. Finite element (FE) simulations and experimental results are used to develop the mechanical model.
Design/methodology/approach
The model incorporates the overall connection and column-beam rotation of key component elements, and includes nonlinear behavior of bolts and base materials at elevated temperatures and some major geometric parameters that impact the behavior of such connections when exposed to fire. This includes load ratio, beam length, angle thickness, and gap distance. The mechanical model consists of multi-linear and nonlinear springs that predict each component stiffness, strength, and rotation.
Findings
The capability of the FE model to predict the strength of top and seat angles under fire loading was validated against full scale tests. Moreover, failure modes, temperature at failure, maximum compressive axial force, maximum rotation, and effect of web angles were all determined in the parametric study. Finally, the proposed mechanical model was validated against experimental results available in the literature and FE simulations developed as a part of this study.
Originality/value
The proposed model provides important insights into fire-induced axial forces and rotations and their implications on the design of steel bolted top and seat angle connections. The originality of the proposed mechanical model is that it requires low computational effort and can be used in more advanced modelling applications for fire analysis and design.
Keywords
Acknowledgements
The authors gratefully acknowledge the financial support provided by the American University of Beirut Research Board under grant No.21113-102726, and by the Lebanese National Council for Scientific Research (LNCSR) under grant No. 103091-2296.
Citation
El Kalash, S. and Hantouche, E. (2017), "Mechanical modeling for predicting the axial restraint forces and rotations of steel top and seat angle connections at elevated temperatures", Journal of Structural Fire Engineering, Vol. 8 No. 3, pp. 258-286. https://doi.org/10.1108/JSFE-05-2017-0033
Publisher
:Emerald Publishing Limited
Copyright © 2017, Emerald Publishing Limited