Seismic Performance Assessment of Steel Frames with Double I-Shape Columns Containing Welding Defects and Strengthened with Carbon Fibers

In recent years, welding defects in steel columns and the resulting damage due to human error or environmental factors have become one of the major problems in steel structures. Therefore, retrofitting and repairing weld joints is essential to maintain structural safety and performance. The main objective of the present study is to investigate the effect of carbon-fiber-reinforced polymers (CFRP) on strengthening double I-shape steel columns that contain welding-induced defects. To this end, seven double columns were modeled in the finite-element software ABAQUS. A sound, fully welded specimen was used as the reference. Three specimens with simulated welding defects and three further defective specimens strengthened with CFRP sheets were analyzed. Strengthening with CFRP in the defect zone was modeled in detail for the latter three specimens. The results show that applying CFRP to the upper quadrant of the column yields the greatest improvement in energy absorption and strength. The CFRP sheets increased the energy absorption and strength by ۲۶% and ۴۰%, respectively, while a reduction in ductility was observed in the strengthened double columns.

کلیدواژه ها:

Seismic Performance ، Double Column ، Welding Defect ، Carbon Fiber ، ABAQUS