This study aims to give a brief summary of the development in the series of studies that have been made regarding the lateral-torsional buckling (LTB) capacity of beam spans with increased cross section at one end, also known as singly stepped beam (SSB), and at both ends, also known as doubly stepped beam (DSB). A three-dimensional program ABAQUS was used to analyze buckling through finite element method, while a statistical regression program MINITAB was used in developing and proposing simple design equations. The following topics discussed in this study include: (1) proposed design equation that account for change in cross section of stepped beams under uniform moment; (2) proposed design equation, with a corresponding moment gradient factor equation, of stepped beams under general loading conditions; (3) proposed design equation for stepped beam with continuous top flange lateral bracing; (4) proposed design equation for monosymmetric stepped beam subjected to uniform moment and to general loading conditions; (5) effect of inelastic buckling of stepped beams subjected to pure bending and general loading conditions considering combined effects of residual stress and geometrical imperfection; and (6) determination of LTB strength of monosymmetric stepped beam by conducting destructive test of subjecting a beam to concentrated load. The summary presented provides researchers information in understanding the subject matter; moreover, this provides a meaningful contribution to futures researches.

ABSTRACT
 1. Introduction
 2. Background and Previous Studies
 3. Modeling and Experimentation
 4. Design Recommendations
 5. Conclusions
 References

• Hannah Reyno(Dept. of Civil Engineering, Sangmyung University)
• Albert Surla(Dept. of Civil Engineering, Sangmyung University)
• 강민정(Dept. of Civil Engineering, Sangmyung University) | Min Jung Kang
• 박종섭(Dept. of Civil Engineering, Sangmyung University) | Jong Sup Park