Yield Moment of Cold-Formed Steel Beams under Different Strain Rates

Abstract

It has been recognized that the mechanical properties of sheet steels and the structural strength of cold-formed steel members can be influenced by strain rate. For studying the local and postbuckling behavior of stiffened and unstiffened compression elements under a dynamic loading condition, 60 beams, which were assembled from the same material, have been tested under different strain rates. To study the structural behavior of hybrid cold-formed steel beams, a total of 72 specimens was investigated. The results showed that the strength of beams increases with increasing strain rates. The amount of increase was found to be dependent on the material yield strength, type of steel, stress-strain relationships, width-to-thickness ratio, type of compression element, and strain rate used in the test. In this research, design procedures were also developed to compute the load-carrying capacity of hybrid beams under different strain rates.