Computation of story drifts considering panel zone deformations for multistory steel moment frames with welded flange plate connections

2008 ◽  
Vol 17 (2) ◽  
pp. 419-443 ◽  
Author(s):  
J. Kent Hsiao ◽  
William Schultz ◽  
Troy Petersen ◽  
Stephen Vaicik
Keyword(s):  
Moment Frames ◽  
Steel Moment Frames ◽  
Panel Zone ◽  
Plate Connections

scholarly journals Seismic Demands in Column Base Connections of Steel Moment Frames

2018 ◽  
Vol 34 (3) ◽  
pp. 1383-1403 ◽  
Author(s):  
Pablo Torres-Rodas ◽  
Farzin Zareian ◽  
Amit Kanvinde
Keyword(s):  
Time History ◽  
Base Plate ◽  
Moment Frames ◽  
Steel Moment Frames ◽  
Seismic Demands ◽  
Axial Forces ◽  
Plate Connections ◽  
Nonlinear Time History ◽  
Base Connections ◽  
Column Base

Methods for the seismic design of base connections in steel moment frames are well-developed and routinely utilized by practicing engineers. However, design loads for these connections are not verified by rigorous analysis. This knowledge gap is addressed through nonlinear time history simulations using design-level seismic excitation that interrogate demands in column base connections in 2-, 4-, 8-, and 12-story steel moment frames, featuring base connections that reflect current U.S. practice. The results indicate that: (1) for exposed base plate connections, lower bound (rather than peak) estimates of axial compression are suitable for design because higher axial forces increase connection strength by delaying base plate uplift; (2) even when designed as pinned (as in low-rise frames), base connections carry significant moment, which can be estimated only through accurate representation of base flexibility; and (3) the failure of embedded base connections is controlled by moment, which may be estimated either through overstrength or capacity-based calculations.

Analytical Methodology to Predict the Beam Overstrength Considering the Composite Slab Effects

2018 ◽  
Vol 763 ◽  
pp. 826-834
Author(s):  
Tushar Chaudhari ◽  
Gregory A. MacRae ◽  
Des Bull ◽  
George Charles Clifton ◽  
Stephen Hicks
Keyword(s):  
Steel Frames ◽  
Lateral Force ◽  
Moment Frames ◽  
Steel Moment Frames ◽  
Design Strength ◽  
Analytical Methodology ◽  
Panel Zone ◽  
Proposed Model ◽  
The World ◽  
Moment Resisting

The design strength of moment resisting steel frames in seismic regions around the world is generally calculated without considering strength enhancement caused by the slab. For column and panel zone design in New Zealand, the beam overstrength including the slab effect is considered. If the slab could be detailed to provide reliable lateral force resistance, then considering it directly in design would result in smaller beam sizes and more economical steel frames. In this paper, a simple analytical model (considering all key modes of failures) to predict the variation in strength due to the presence of the slab is proposed and validated with the experimental data. The proposed model to develop dependable slab contributions may change the design of steel moment frames around the world.

scholarly journals Adopting flexibility of the end-plate connections in steel moment frames

2015 ◽  
Vol 18 (5) ◽  
pp. 1215-1237 ◽  
Author(s):  
M. Ghassemieh ◽  
M. Baei ◽  
A. Kari ◽  
A. Goudarzi ◽  
D.F. Laefer
Keyword(s):  
Moment Frames ◽  
Steel Moment Frames ◽  
End Plate ◽  
Plate Connections

scholarly journals Optimization of steel moment frames with panel-zone design using an adaptive differential evolution

2020 ◽  
Vol 14 (2) ◽  
pp. 65-75
Author(s):  
Viet-Hung Truong ◽  
Ha Manh Hung ◽  
Pham Hoang Anh ◽  
Tran Duc Hoc
Keyword(s):  
Differential Evolution ◽  
Differential Evolution Algorithm ◽  
Adaptive Mutation ◽  
Moment Frames ◽  
Steel Moment Frames ◽  
Panel Zone ◽  
Local Searches ◽  
Direct Design ◽  
Adaptive Differential Evolution ◽  
Mutation Strategy

Optimization of steel moment frames has been widely studied in the literature without considering shear deformation of panel-zones which is well-known to decrease the load-carrying capacity and increase the drift of structures. In this paper, a robust method for optimizing steel moment frames is developed in which the panel-zone design is considered by using doubler plates. The objective function is the total cost of beams, columns, and panel-zone reinforcement. The strength and serviceability constraints are evaluated by using a direct design method to capture the nonlinear inelastic behaviors of the structure. An adaptive differential evolution algorithm is developed for this optimization problem. The new algorithm is featured by a self-adaptive mutation strategy based on the p-best method to enhance the balance between global and local searches. A five-bay five-story steel moment frame subjected to several load combinations is studied to demonstrate the efficiency of the proposed method. The numerical results also show that panel-zone design should be included in the optimization process to yield more reasonable optimum designs. Keywords: direct design; differential evolution; optimization; panel-zone; steel frame.

scholarly journals DETERMINING THE OPTIMAL GEOMETRY OF RBS CONNECTION FOR ENHANCEMENT OF SEISMIC BEHAVIOR OF STEEL MOMENT FRAMES

2016 ◽  
Vol 38 (2) ◽  
pp. 1116
Author(s):  
Hossein Khosravi ◽  
Vahidreza Kalatjari ◽  
Hadi Einabadi
Keyword(s):  
Seismic Behavior ◽  
Plastic Hinge ◽  
Seismic Loads ◽  
Moment Frames ◽  
Steel Moment Frames ◽  
Finite Element Software ◽  
Cutting Geometry ◽  
Panel Zone ◽  
Local Reduction ◽  
Beam Section

In a RBS connection, the stress concentration is being prevented on the location of joint via local reduction of beam section near the column and the place of plastic hinge is being transferred from connection to a section of a beam near to the column. A special ilk of RBS connection which is named dogbone connection and its beam wings are cut from a circle in an arcuate form, has displayed a desirable performance against to the seismic loads. This paper aims at obtaining the best cutting geometry of the beam wing in order to improve the performance of the connection against to the seismic loads. For this purpose in this research, we have opted a several panel zone with different dimension on the beam wing under the influence of the seismic loads in Finite Element software called Abaqus along with a cyclic loading, modeled displacement control index and the best sample of cutting dimension among from the samples that are modeled.

Effects of Fling Step and Forward Directivity on Seismic Response of Buildings

2006 ◽  
Vol 22 (2) ◽  
pp. 367-390 ◽  
Author(s):  
Erol Kalkan ◽  
Sashi K. Kunnath
Keyword(s):  
Seismic Response ◽  
Ground Motions ◽  
High Amplitude ◽  
Moment Frames ◽  
Steel Moment Frames ◽  
Damage Potential ◽  
Near Fault ◽  
Forward Directivity ◽  
Fling Step ◽  
Far Fault

This paper investigates the consequences of well-known characteristics of near-fault ground motions on the seismic response of steel moment frames. Additionally, idealized pulses are utilized in a separate study to gain further insight into the effects of high-amplitude pulses on structural demands. Simple input pulses were also synthesized to simulate artificial fling-step effects in ground motions originally having forward directivity. Findings from the study reveal that median maximum demands and the dispersion in the peak values were higher for near-fault records than far-fault motions. The arrival of the velocity pulse in a near-fault record causes the structure to dissipate considerable input energy in relatively few plastic cycles, whereas cumulative effects from increased cyclic demands are more pronounced in far-fault records. For pulse-type input, the maximum demand is a function of the ratio of the pulse period to the fundamental period of the structure. Records with fling effects were found to excite systems primarily in their fundamental mode while waveforms with forward directivity in the absence of fling caused higher modes to be activated. It is concluded that the acceleration and velocity spectra, when examined collectively, can be utilized to reasonably assess the damage potential of near-fault records.

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