BOLTED CONNECTIONS FOR NON-INTERSECTING H-SECTION BEAM AND COLUMN IN STEEL MOMENT FRAMES

This research proposes connection configurations of two types for non-intersecting H-section steel beam and column. To elucidate the mechanical behavior of the proposed connections, full-scale moment connection tests and finite element analyses were conducted using T-shaped partial frame models. Comparisons between the proposed connections and regular intersecting connections demonstrate that the proposed connection is able to provide sufficient stiffness and energy-dissipation capacity if the beam and column flanges are designed to provide sufficient shear resistance. Then to understand the global behavior of frames using the proposed connections, pushover analyses of a two-story two-span frame were conducted. Because the bending moment of the beam acts on the column by a torque through the proposed connections, torsion spring models were incorporated for representing the proposed connections in 3D frame analysis. Analysis results showed that the girders and columns exhibited lower stiffness and strength than those of frames with intersecting connections because of torsion. To overcome this issue, torsion restraint by secondary beams with different configurations was discussed and optimal configuration was suggested. By utilizing the optimal configuration, torsion of girders and columns can be efficiently reduced into a similar level as that of regular intersecting connections.

Compactifications of partial frames via strongly regular ideals

Partial frames provide a fertile context in which to do pointfree structured and unstructured topology, using a small collection of axioms of an elementary nature. Amongst other things they can be used to investigate similarities and differences between frames, σ-frames and κ-frames. In this paper, the theory of strong inclusions for partial frames is used to describe compactifications of completely regular partial frames; the elements of these compactifications are given explicitly as strongly regular ideals. This is independent of and encompasses the theory of compactifications for frames. As an application, we revisit the Samuel compactification of a uniform partial frame.

Simplified Second-Order Analysis of Semirigid Connected Steel Frames

The aim of this paper is to present a practical yet simplified method in the second-order analysis of semirigid connected steel frames. Based on the principle of new shear force distribution method, by taking partial frame as an analytical subassembly model and using a rotation spring which has variable bending stiffness to model flexibility of beam-column connection, this paper derives a simplified non-iterative inner force and lateral deflection computation formula considering P-Delta effects on semirigid connected steel frames. The numerical examples show that semirigid of beam-column connections obviously increases the horizontal displacement and P-Delta effect on the steel frame. Therefore the influences of semirigid connection should been considered in second-order analysis of building steel frame. The presented method is not only relatively practical and easily applicable to manual computation but also has a rather high accuracy, and can be used by the engineers in preliminary design for semirigid connected steel frames.