doi:10.3850/978-981-08-7920-4_S2-S07-cd
Optimized Non-Linear Solution for Bending Wide Flange Steel Beams About their Strong Axis
Antoine N. Gergess1 and Rajan Sen2
1Department of Civil Engineering, University of Balamand, EL-Koura, Lebanon.
2Department of Civil and Environmental Engineering, University of South Florida,
Tampa, FL, USA.
ABSTRACT
Cold bending is commonly used for inducing cambers in wide flange steel beams. In this
process, the girder is bent about its strong axis using single or dual symmetrically applied
concentrated loads and the desired camber develops based on the induced permanent mid-span
deformation. In the absence of set criteria, the accuracy of the method relies exclusively on trial
and error. This paper derives a non-linear solution that can accurately predict the magnitude of
the loads and induced deformations for double-ram systems,which allows optimizing themand
increasing their efficiency. Closed form solutions are derived based on idealized elasto-plastic
stress-strain curves as a function of the steel girder shape and geometry. Loads are calculated
from inelastic stress distributions and equilibrium of moments. Induced deformations are
determined from integration of curvatures. Sensitivity analyses are then conducted to identify
appropriate values of loads and deformations and their impact on alternative cambering set-ups
for dual-load systems. The analysis shows that these systems can develop the required camber
profile at small loads without overstraining the steel section. The best results are obtained if
the spacing between the loads is kept within one-third to one-quarter of the span. Limits on
loads and residual strains that prevent localized damage are finally proposed to ensure they are
within acceptable norms.
Keywords: Cambering, Bending, Optimized, Parametric, Wide flange, Steel, Permanent, Buckling.
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