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Design of Connections for Steel Members
Published in John F. Unsworth, Design and Construction of Modern Steel Railway Bridges, 2017
In general, gusset plates should be designed to be as compact as possible. This not only reduces material consumption, but also reduces slenderness ratios and free edge distances for greater buckling strength. Gusset plates have been traditionally designed using beam theory to determine axial, bending, and shear stresses at various critical sections of the gusset plate. However, the slender beam model is not an accurate model* and considering the limit states of block shear (tear-out) and axial stress, based on an appropriate area, it is used for the design of ordinary gusset plates.
Innovative Strengthening Method for Steel Truss Nodes—Experimental Results
Published in Structural Engineering International, 2019
Stoyan Ivanov, Roman Geier, Carlos Rebelo, Bruno Pedrosa
This innovative technic is aiming to solve the main problems, found in the truss nodes and related to: Gusset plates—too thin or corroded gusset plates, where local buckling or shear tearing might govern the design;Connecting rivets—strengthening the connection of the elements entering the node might be restricted by the possibilities to add additional bolts or rivets, because of the small space available between the existing connectors and the optimised geometry of the gusset plates.
Seismic Performance of Precast Concrete Frames with Buckling-Restrained Braces
Published in Journal of Earthquake Engineering, 2023
Shuangshuang Cui, Yan Chen, Jean Christophe Mwizerwa, Weihong Chen, Zhiyu Chen
When Δ reached +3 mm, BRBs entered the yielding stage; at this stage, there were no cracks on the BRBs-PC frame. When Δ reached −3 mm (the third load cycle), the corner of the R-zone column cracked, two cracks of the same width, of 0.02 mm were observed. When Δ reached +10 mm, the concrete at the upper end of the column’s embedded part in the R-zone cracked, with a crack width of 0.16 mm. When Δ reached +15 mm (the second load cycle), part of the beam’s longitudinal reinforcements began to yield, while the column’s longitudinal reinforcements did not. When Δ reached −20 mm (the first load cycle), part of the column’s longitudinal reinforcements began to yield. When Δ reached +20 mm (the second load cycle), the concrete at the bottom of the L-zone beam started to spall slightly, with the widest crack reaching 1.17 mm. When Δ reached +25 mm, the concrete at the upper end of the column’s embedded part cracked, with the widest crack reaching 1.97 mm. When Δ reached +30 mm (the second load cycle), the R-zone of the BRB (BRB-R) made a sudden creaking sound; the BRB-R had broken and, therefore, the BRB failed. At this time, several cracks appeared on the concrete at the embedded part of the beam’s mid-span; the widths of which were approximately 0.24 mm. After that, the phenomenon of concrete spalling was not obvious during loading, and the BRB’s axial force had less influence on the mid-span concrete. When Δ reached −35 mm (the second load cycle), the L-zone of the BRB (BRB-L) made a creaking sound and then broke. Therefore, when Δ reached ±35 mm, both BRBs, in the L and R zones, had been pulled out, but the connecting plates and the welded joints were still intact. When Δ reached ±40 mm, more concrete spalling in the column’s embedded parts was observed, which was mainly distributed in the front and back zones where the embedded parts intersect, while the concrete at the bottom of the column exhibited no significant damage. The gusset plate is in the foundation beam-column joint could cause column-end plastic hinges to be shifted out of the gusset connection region, and the damage level could be increased due to the shortening of effective lengths of the column. When Δ reached +45 mm, large concrete spalling had occurred at the beam end of the L-zone. When Δ reached ±60 mm, the load decreased to 85% of the maximum loading, and the test was terminated. During observation of the entire failure process, there was no bond-slip phenomenon on the superimposed surface of the beam-column. The concrete cracking on the superimposed surface and the mid-region of the beam did not appear to be serious. The final failure state of the beam, the column, the BRBs, etc., is shown in Fig. 17.