Comparison of End Plate Connection Design Between AISC DG4 and GB Codes

End plate connection is commonly used in multi-story buildings, which is widely used in American Standard Design, but rarely in Chinese Standard Design. In response to that, the comparison between American and Chinese standard design is conducted, through which it's found that the American Standard has been deeply investigated, such as AISC DG4, DG16. The DG4 design procedure suits to extended end plates yielding to wind and seismic design (rigid joint). For the beam-column joint of extended end plate, refer to DG13. DG16 suits to flush end plate and extended end plates yielding to non-seismic or wind design (semi-rigid joint). In contrast, associated calculation procedure per Chinese Standard is quite preliminary. Both JGJ 82-2011 Technical Specification for High Strength Bolt Connections of Steel Structures ("Bolt Regulations" hereinafter) and GB 51022-2015 Technical Code for Steel Structure of Light-weight Building with Gabled Frames ("Gabled Frames Specifications" hereinafter) provide clauses dealing with end plate connection design, but the plate thickness calculation method is not given in the Bolt Regulations, only with a mandatory term of plate thickness no less than 16mm nor less than the bolt diameter being identified. Meanwhile, calculation method of bolt arrays is not given in Gabled Frames Specifications, but only providing the end plate thickness calculation. Neither of these standards integrates the end plate connection design procedure.
In order to rationalize the bolt and end plate design of the connection, also to valid the end plate connection as rigid joint in Chinese Standard Design, the article presents what distinctively different between AISC DG4 and GB/JGJ since the researching history, calculation theory, assumptions, case studies and analysis.
The connection tension member design concurs between AISC DG4 and GB/JGJ, the bolt sizing procedures are basically the same, but the calculation of the end plate thickness varies drastically in between, Yield Line Theory was adopted by American Standard considering the controllable plastic development, in contrary, the Chinese Standard proceeds extremely conservatively, all the calculations are limited within the elastic theory.
Looking into Appendix B of AISC DG4, the end plate thickness is less than the bolt diameter in majority of the cases, especially for end plate of 50 ksi (equals to 345 MPa) and above, this criteria prevails. Even though the Chinese Standard leads a safe end plate connection design via mandatory requirements of end plate thickness no less than bolt diameter, column flange thickness no less than end plate thickness, stiffening of the extended end plate, and so forth, but obviously the AISC DG4 leads to reasonable design, especially for cases yielding to seismic requirements.
By comparing above research, we find that the theory of AISC DG4 is relatively clear, and can be supported by engineering and test data. In seismic design, if the engineers determine that the theory of GB code is not applicable, they can design according to AISC DG4. In non-seismic condition, the construction measures required in GB code are safe enough.