Comparisons Between Chinese and American Standards on Welded Connection Design

The welding is the main connecting method for steel structures. Every country in the world has published corresponding technical standards to regulate the design and construction requirements on welded connection design. This paper summarizes and compares the basic requirements and design methods for welded connections of steel structure in the current Chinese Standard for Design of Steel Structures(GB 50017-2017), American Specification for Structural Steel Buildings(AISC 360-16) and affiliated technical specifications, analyzes and discusses welding types, detailing requirements, quality inspection, resistance calculations and other provisions specified in GB 50017-2017 and AISC 360-16 and relevant technical specifications. The paper is focuses on the differences and similarities between the technical standards of the two countries, and the main contents are:
1)Technical standards on welded connections. The design provisions on welded connections in the United States is regulated by various professional society. The American Welding Society has released the AWS standards for welding materials and welding processes. The American Society for Testing and Materials has provided the ASTM standards for structural steel and connection materials. The American Institute of Steel Construction has formulated the AISC standard for determining resistance and requirements of welded connections. However, the welded connection design in China should be in accordance with the national GB standard or JGJ standard published by the Chinese government.
2)Types of welded connection. The types of welded connections recommended by GB 50017 and AISC 360 are more or less the same, including fully penetrated butt weld, partially penetrated butt weld, fillet weld, plug weld and slot weld. The detailed requirements in the two standards for various types of welded connections are basically similar.
3)Design principle of welded connections. GB 50017 requires to follow Limit State Design to determine the resistance of various welded connections, while AISC 360 allows structural engineers to take Allowable Strength Design or Load and Resistance Factors Design, which is equivalent to Limit State Design, to determine the resistance of welded connections.
4)Analysis of butt welds. GB 50017 determines the resistance of fully penetrated butt weld according to the specified design strength of butt weld, while AISC 360 assumes the strength of welding equal to the parent metal as long as the details, welding process and quality inspection satisfying the requirements. For the resistance of partially penetrated butt weld, the calculation method equivalent to fillet weld is applied in both standards.
5)Analysis of fillet weld. The methods to determine the resistance of fillet weld, plug weld and slot weld specified in GB 50017 and AISC 360 are fundamentally identical, but the resistance of fillet weld given by AISC 360 is slightly higher than that of GB 50017. Both standards apply a reduction factor to consider the shear force distribution in long fillet weld.
Above all, this paper provides a guide for structural engineers to understand and apply GB 50017 and AISC 360 efficiently. Some suggestions and recommendations are also proposed for further improving GB 50017-2017.