内容提要（Outline）：

Buckling resistance of thin-walled I-section steel-concrete composite beams subjected to hogging bending is related to lateral, lateral-torsional or torsional distortional buckling of the beam section unrestrained flange and web. The buckling resistance of I-section rolled plain-webbed composite beams subjected to hogging bending is well researched and corresponding design procedures are codified. However, in many practical applications, the composite beams are more frequently made of welded thin-walled I-sections with large web openings. The presentation is concerned with experimental and numerical investigations into the distortional buckling and post-buckling behavior of specimens containing the plain-webbed span and the castellated overhanging part with different number of openings and different opening shapes, and subjected to the concentrated force acting at the tip of overhang. The summary of predicted buckling strength of tested beams is given. A practical design procedure is developed that is based on the direct strength method.

 报告人（About the Speaker）:

Dr. Marian Gizejowski is the Professor of Structural Engineering holding the Civil Engineering Faculty position of the Warsaw University of Technology. He is the Deputy Dean for Scientific Research. His research interest focuses on structural stability, modeling of nonlinear behavior of metal and composite steel-concrete structures, structural assessment and code development of limit states criteria, extreme actions on structures and collapse analysis, monitoring of structural safety and serviceability. He has authored over 300 different publications. Presently he chairs the Metal Structures Section of the Civil Engineering Committee of the Polish Academy of Sciences and co-chairs the Science Committee of the Polish Association of Civil Engineers and Technicians.