EFFECT OF RESIDUAL-STRESS ON COLD-FORMED STEEL COLUMN STRENGTH

Abstract

The effect of residual stress on the flexural buckling strength of cold-formed steel columns is studied. Based on the results of 93 column tests and the measured residual stresses, significant relation is observed between the reduction of column strength, the magnitude and distribution of residual stress, and the flat-width ratio of the plate element of the cold-formed section. In this study, a new concept called the "second reduction" is developed to account for the effect of the residual stresses on the local buckling behavior of cold-formed steel columns. Based on this concept, a possible design procedure is outlined for the prediction of the flexural buckling strength of cold-formed steel columns. The theoretical predictions are found to be in good agreement with the test results.