이철호 교수

This paper presents test results on eight reduced beam section (RBS) steel moment connections. The testing program addressed web connection type (bolted versus welded) and panel zone (PZ) strength as the key variables. Specimens with medium PZ strength were designed to promote energy dissipation from both PZ and RBS regions such that expensive doubler plates were not needed. Both strong and medium PZ specimens with a welded web connection were able to provide satisfactory connection rotation cap

Flexural tests on full-scale I-shaped beams, built up from high-strength steels (HSB800 and HSA800) with a nominal tensile strength of 800 MPa, were carried out to study the effect of flange slenderness on flexural strength and rotation capacity. The primary objective was to investigate the appropriateness of extrapolating current stability criteria (originally developed for ordinary steel) to high-strength steel. For comparison purposes, specimens with ordinary steel (SM490) were also tested an

This paper describes a seismic design procedure for rib-reinforced steel moment connections based on an equivalent strut model. It is shown from the results of finite-element analysis that the force transfer mechanism in the rib connections is completely different from that predicted by the classical beam theory and that a diagonal strip in the rib acts as a strut. By treating the rib as a strut, an equivalent strut model that could be used as the basis of a practical design procedure is propose

In this study, the behavior of high-strength steel circular hollow section (CHS) X-joints was systematically investigated by experimental and test-validated numerical analysis. A total of nine CHS X-joints fabricated from cold-formed tubes were tested under axial compression. The key test variables included different grades of steels and geometrical configuration of the joint. The joint strength observed was mostly governed by the widely accepted 3% indentation criteria before reaching the peak

In this study, a parallel axial-flexural hinge model capable of representing postyield flexural behavior and considering interaction effects of axial force and moment is proposed for a simplified nonlinear progressive collapse analysis of welded steel moment frames. To this end, the load-resisting mechanism of the column-removed double-span beams was investigated based on the material and geometric nonlinear parametric finite-element analysis. A multilinear parallel point hinge model which captu

This paper describes the analytical modeling and a seismic design procedure for steel moment connections with a welded straight haunch. Recent test results showed that welding a straight haunch beneath the beam could be a viable solution for repair and rehabilitation of pre-Northridge moment connections and also new construction. Although a design procedure for the connection with a triangular welded haunch has been developed recently, it is not applicable for the straight haunch moment connecti