Effect of residual stresses and cold-straightening on the compressive resistance of solid round steel columns

The objective of this research is to study the effects of residual stresses and cold-straightening on the compressive resistance of solid round steel columns. Thermal residual stresses in selected solid round sizes were determined from experimental study, finite element analysis, and previous research. In the experimental investigation, classical boring-out method using water-jet technology was applied on four samples with different diameters. Finite element models were constructed for the determination of thermal reidual stresses for columns with 12 different diameters. The results were then compared with results obtained from a recent study on the predictionof symmetrical residual stresses in solid rounds using X-ray diffraction method. For the non-symmetrical residual stresses arising from cold-straightening, the equation developed by Nitta and Thurlimann was adopted in the finite element modeling to study the effect of non-symmetrical residual stresses on the compressive resistance of solid round steel columns. The Finite Element Analysis has been conducted on different bar diameter (1.5 inch to 12 inch diameter) and length, as well as initial out-of-straightness.