The Earthquake Engineering Online Archive

Further studies on seismic behavior of steel beam-column subassemblages

Bertero, Vitelmo V.; Krawinkler, Helmut; Popov, Egor P.

UCB/EERC-73/27, Earthquake Engineering Research Center, University of California, Berkeley, 1973-12, 99 pages (530/B37/1973)

In a previous report, entitled "Inelastic Behavior of Steel Beam-to-Column Subassemblages," experimental results and evaluation of four structural steel subassemblages representing a portion of a moment-resisting frame have been reported. The investigation of the shear deformation of the panel zone under cyclic loading received special emphasis, and it was shown that for some situations this deformation could significantly contribute to the story drift. The present report contains the most significant experimental results and interpretation of four additional structure steel subassemblages subjected to severe quasistatic load cycles. As before, the test specimens consisted of two beams framing into a central column, the members being rolled sections of A36 structural steel. The main objectives of the second series of experiments were (a) to study the effectiveness of increasing the shear resistance of beam-column joints by reinforcing their panel zones by means of plate stiffeners, (b) to investigate the effects of different joint strengths and stiffnesses on the overall behavior of subassemblages, (c) to study the effects of local instabilities on the hysteretic behavior of subassemblages. An analytical model for the load-deformation response of joints is suggested, and a design equation for the required panel thickness of joints with or without doubler plates is proposed. Conclusions are drawn regarding the design of beams and joints to provide the subassemblage with maximum energy dissipation capacity. Another report on similar subassemblages with the plastic hinges occurring in the columns is in preparation.

Available online: http://nisee.berkeley.edu/documents/EERC/EERC-73-27.pdf (9 MB)