Lateral distortional buckling in steel-concrete composite beams: A review

Abstract

Steel-concrete composite beams, when requested by negative moment, can fail due to Lateral Distortional Buckling (LDB), local buckling, by a combination of these stability modes or achieve the plastic behavior. LDB is a mode of stability in which the web must distort in order for the compression flange to displace and twist during buckling. Several papers were published in an attempt to clarify the LDB behavior of steel-concrete composite beams. These papers can be divided into two strands of studies. The first that seeks to investigate the elastic behavior of the LDB, in an attempt to determine the elastic critical moment, through bifurcational equilibrium analyzes. And the second strand, which investigates the LDB strength of steel-concrete composite beams, through the development of experimental investigations or by non-linear numerical analyzes. However, there is still no consensus regarding the behavior of LDB in steel-concrete composite beams. Researchers who investigated the elastic behavior of LDB show divergences between the methodologies for determining the elastic critical moment. Furthermore, the publications that are aimed at investigating the LDB strength, show inconsistencies in the standard procedures. Therefore, the main objective of this article is to present a critical review about LDB in steel-concrete composite beams. For this purpose, the main studies that analyzed the elastic and inelastic behavior of LDB are presented, in addition to an overview of the main standard procedures. Finally, the future research directions have been discussed, presenting parameters that still need further investigation.