摘要

Shear links are key components in the Eccentrically Braced Frames (EBFs) that act as a structural fuse by dissipating seismic energy during severe earthquakes. Specification AISC 341, which is frequently used in the seismic design of steel structures, prescribes a constant overstrength factor of 1.50 for shear links. However, a few existing experimental results indicated that the overstrength of very short shear links with length ratio lower than 1.0 are much greater than required. In this paper, five basic factors influencing the overstrength of very short shear links are summarized as follows: web-ultimate-to-yield-shear-strength ratio, lengthto- stiffener-spacing ratio, flange-to-web-area ratio, flange-to-web-strength ratio, length-to-depth ratio. A numerical investigation with a detailed Finite Element (FE) model, verified by a comparison with existing experimental results, is conducted to investigate the combined effects of these five basic factors on the overstrength of very short shear links. Then, a new numerical model for predicting the overstrength value is proposed based on the FE analysis results and existing available experimental data by using the numerical fitting method, and it shows good agreement.