مشخصات پژوهش

In this work, a comprehensive parametric study, based on a robust finite element analysis validated by existing experimental results, was conducted to investigate the effects of plate slenderness, cope details, i.e. depth (dc), length (Lc), and initial geometrical imperfection, on the elastic, inelastic, and post-buckling behavior of top flange coped I-beams with slender web panel (CBSW). The analysis results showed that the primary failure mode is elastic/inelastic shear local buckling, resulting in the formation of an inclined tension field band on the coped web from the cope corner during the post-buckling stage. The ultimate resistance and failure mode of CBSWs are generally affected by both cope details and imperfection magnitude. A small cope (dc/D ≤ 0.2 and Lc/D ≤ 0.2, where D is beam depth) has a negligible effect on the elastic buckling mode shape and elastic local buckling resistance of CBSWs. Moreover, the failure mode of CBSWs generally shifts from inelastic local buckling to elastic local buckling (ELB) when decreasing the imperfection magnitude or increasing the web slenderness, cope depth, and cope length. The current design equations were found to accurately predict the ELB resistance of CBSWs with a maximum difference within 13 %, but grossly overestimate (some cases up to 117 %) the ultimate strength of CBSWs with small cope areas. To address this, a new equation was developed and significant improvement in the accuracy of the design prediction was obtained, particularly for CBSWs with small copes.