Enhancing axial compressive capacity of angle steel via an innovative in-situ non-destructive local internal patch bonding technique

Addressing the dual threat of artificial intelligence (AI) driven transmission capacity demands and increased structural vulnerability to extreme weather, this study proposes a novel in-situ non-destructive reinforcement method for original angle steel via local internal patch bonding (LIPB). It involves using round steel buckles to connect and secure the original angle steel and reinforcing angle steel, forming a C-shaped fastening. This method can maintain almost no deviation in the center of mass axis of original component. Axial compression tests were conducted to examine the failure modes and capacity of reinforced and original members with different slenderness ratios and reinforcing lengths. The experimental results demonstrate that the LIPB reinforcement method can effectively increase the bearing capacity of angle steels by between 6.9% and 43.6%, depending on the angle steel specifications. Unreinforced members exhibited mid-span flexural buckling failure, whereas LIPB members exhibit local bending deformation at the edges of reinforcing region. The FEA results indicate that the ultimate bearing capacity of members increases with the increase of slenderness ratio, width to thickness ratio and reinforcing length factors, especially for members with large slenderness ratio, the reinforcement effect of LIPB member is more significant. In addition, based on the axial compression stability model, a formula for calculating the ultimate bearing capacity considering slenderness ratio, width to thickness ratio, and reinforcing length factors is proposed. This formula has a good correlation with the test and 120 numerical simulation results and can be used as a reference for engineering applications.