New points in TCVN 5575:2024 and the use of bi-moment in the strength verification of flexural members

Abstract

In countries with advanced science and technology, important standards in the field of structural design for buildings and civil structures - particularly in steel and reinforced concrete structures - are constantly monitored, revised, or updated. The Vietnamese standard TCVN 5575:2012 - Steel Structures - Design Standard has been in effect for 13 years since its issuance and has now been replaced by the new version TCVN 5575:2024. This paper focuses on analyzing and presenting several notable updates introduced in TCVN 5575:2024, including: the structure of the standard, its scope of application, classification of structural members and structural groups, design strength of materials and steel structural connections, as well as reliability factors. In the structural design section, several updated aspects in the calculation of flexural members are analyzed with consideration of the bi-moment component. The application of TCVN 5575:2024 also emphasizes critical updates concerning material grades, reliability factors, and the effect of bi-moment forces in conducting strength checks and connection calculations for a Grade 1 steel beam with a closed rectangular hollow section and an open-section thin-walled C - beam. The analysis demonstrates that the updates in TCVN 5575:2024 - Steel Structures - Design Standard are harmonized with international standards, enhance structural safety, optimize design efficiency, and improve constructability in the field of steel structures