Accounting for moment-rotation behaviour of connections in portal frames
Date
2014-04
Journal Title
Journal ISSN
Volume Title
Publisher
South African Institution of Civil Engineering
Abstract
Portal frames are steel structures used to construct industrial buildings. Conventional analysis
techniques used by practising engineering professionals assume that the eave, ridge and base
connections are either infinitely rigid or perfectly pinned. This approach leads to less accurate
analysis of the displacement behaviour of portal frames when subjected to external loading.
Portal frames must therefore be analysed with rotational springs at all connections to yield
accurate displacement behaviour. This investigation focused on determining the accuracy
and economic feasibility of modelling portal frame connections with rotational springs. The
rotational spring stiffnesses of all connections were required before the portal frame could
be analysed in a second-order two-dimensional non-linear analysis. The rotational spring
stiffnesses unique to each connection were determined from the moment-rotation behaviour
obtained from a series of finite element analysis simulations of each connection. Thereafter
these stiffnesses were used to determine the vertical and horizontal displacements of the portal
frame. These displacements were compared with experimental test results. The reasons for the
discrepancies between the numerical and experimental results were investigated through
a sensitivity analysis. The findings suggest that it is not computationally feasible to analyse
portal frames with rotational springs, even though the model’s predicted results are more
accurate than those of conventional analysis using rigid and pin connections.
Description
CITATION: Albertyn, H. L., Haas, T. N. & Dunaiski, P. E. 2014. Accounting for moment-rotation behaviour of connections in portal frames. Journal of the South African Institution of Civil Engineering, 56(1):69-76.
The original publication is available at http://www.scielo.org.za
The original publication is available at http://www.scielo.org.za
Keywords
Structural frames -- Joints (Engineering) -- Analysis, Moment-rotation behaviour, Finite element analysis, Steel framing (Building)
Citation
Albertyn, H. L., Haas, T. N. & Dunaiski, P. E. 2014. Accounting for moment-rotation behaviour of connections in portal frames. Journal of the South African Institution of Civil Engineering, 56(1):69-76.