influence of in-plane eccentricity in connection of bracing members to columns and beams on performance of steel frames

steel structures are usually built with some defects. according to the standard building codes, the central axes of the bracing members should go through the beam-column joints, however, in most of the braced steel structures, bracing members are unintentionally connected eccentrically. this paper presents a numerical investigation on performance analysis of cbfs (concentrically braced frames) having unwanted in-plane eccentricities at the connection of their braces. nonlinear behavior analyses are taken as numerical examples. finite element modeling of the whole members is conducted using ansys analyzing program. numerical results show that in-plane eccentricities in beams can be acceptable within a safe region (max. 10cm for this specific case). however, no safe region is found for in-plane eccentricity in columns since the strength loss may be significant. finally, some suggestions are made for decreasing constructional shortcomings of eccentric connections.