Research on the design of overall stability capacity for axial compression and single sided connected eccentric compression equal leg angles

This study investigates the design methods for the overall stability capacity in equal-leg angles under axial compression and those subjected to eccentric compression with single-sided connections. It compares eight current codes from China, Europe, Australia, and the United States, emphasizing the differing design considerations for equal-leg angles. The research is based on 712 sets of axial compression tests and 226 sets of eccentric compression tests with single-sided connections on equal-leg angles, examining the discrepancies between the calculated and tested overall stability capacities as per the codes. The findings indicate significant variations in calculated capacities across the eight codes, with a general inclination towards conservatism in axial compression designs for equal-leg angles. Codes such as AS 4100, AS/NZS 4600, and the general method of EN 1993-1-1 use the axial compression-bending (N-M) interaction equation for eccentric compression, whereas GB 50,017, DL/T 5154, EN 1993-3-1, and the concise method of EN 1993-1-1 use a simplified axial compression formula for eccentric compression. These simplified methods deviate from practical engineering scenarios, especially for single-sided connected eccentric compression equal-leg angles. Following a comprehensive evaluation of the codes and test results, this study suggests a revision to the stability factor in GB 50,017 for axial compression in equal-leg angles. Additionally, it introduces a new design method for the overall stability capacity of single-sided connected eccentric compression in equal-leg angles, drawing on the N-M interaction equation from AS/NZS 4600. The paper concludes with the experimental data validation of the proposed stability factor for axial compression in equal-leg angles and the new design method for eccentric compression in equal-leg angles.