The objectives of this project are to establish the truss analogy approach for analysis of steel beam-to-column connection and to develop a new design procedure and detailing practice for welded connections in steel moment-resisting frames. Modern steel buildings in the wake of the classical Bernoulli hypothesis. The beam bending moment is transferred to the column through the flange welds, while the shear force is taken by the shear tab, which implicitly assumes the capacity of the beam at the beam-to-column connection is the same as the capacity of the beam in the span. However, detailed model analysis showed that the area of the connection near the shear tab is virtually devoid of stresses, while high stress concentrations occurring the flanges and the flange welds. The truss analogy approach is used herein to develop a rational model of force transfer in the beam-to-column connection. The model postulates that the connection bending moment is transferred through the horizontal chord forces, while the connection shear is taken by a diagonal strut. Under bending, the flange welds will be subjected to a complex state of stress and overloaded. The truss analogy approach shows that the beam in the connection is necessarily weaker than in the span. The new design procedure ? is based the rational truss force transfer model. The new design strategy is to increase the capacity of the beam near the connection by adding a flexural and a shear strengthening element. Analytical work needed to achieve the research objectives has been carried out. This project focuses on the experimental research needed to verify the truss analogy approach and refine the proposed beam-to-column connection design procedure. Together, the results will form a base for full-scale proof-testing of the new connection design procedure and detailing practice.
