The effect of panel zone rigidity on behavior of tall buildings with tubular steel moment-frame systems

Beam-to-column panel zone behavior in a steel moment-frame is characterized by the surrounding acting forces and its rotating deformation. When subjected to lateral forces, panel zones are deformed in a parallelogram pattern that one side of its diagonal direction is in tension whereas the other side is in compression. Moreover, right angles at the joints between the beam, column ends and the panel remains right angles. Shear strain causes the panel to rotate at a finite angle characterizing its rotating deformation. Based on experimental results from a full scale steel building collapse test, this paper discusses the elastic and elasto-plastic behavior of some typical panel zones.

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Case Study of a Northridge Welded Steel Moment-Frame Building Having Severed Columns

Earthquake Spectra ◽

10.1193/1.1773593 ◽

2004 ◽

Vol 20 (3) ◽

pp. 951-973 ◽

Cited By ~ 1

Author(s):

Bruce F. Maison ◽

Tom H. Hale

Keyword(s):

Northridge Earthquake ◽

Moment Frame ◽

Steel Moment Frame ◽

Seismic Safety ◽

Welded Steel ◽

Collapse Prevention ◽

The North ◽

Panel Zone ◽

Frame Building ◽

Special Studies

The two-story welded steel moment-frame (WSMF) essential services building had columns severed by the 1994 Northridge earthquake. Two of eight columns suffered fracture across both flanges and panel zones in the WSMFs oriented in the north-south direction. Building and connection damage are described; computer models of the building are formulated and used in a damage correlation exercise that aids in damage interpretation; and a calibrated model is used as the basis of special studies. Factors contributing to the severed columns appear to be column-steel low-fracture toughness, panel zone detailing, and panel-zone shear yielding. Using FEMA-351 guidelines, the as-built as well as the Northridge-damaged structure pass the global collapse prevention drift criterion and fail the local collapse prevention drift criterion. The results provide insight regarding the seismic safety of buildings having similar conditions.

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Cyclic Behavior of Panel Zone in Steel Moment Frame under Bidirectional Loading

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.763.361 ◽

2018 ◽

Vol 763 ◽

pp. 361-368

Author(s):

Yan Dong Wang ◽

Ryota Arakida ◽

Iathong Chan ◽

Yuji Koetaka ◽

Tatsuya Nakano

Keyword(s):

Aspect Ratio ◽

Cyclic Behavior ◽

Severe Damage ◽

Moment Frame ◽

Steel Moment Frame ◽

Panel Zone ◽

Total Input ◽

Story Drift ◽

Flange Beams ◽

Loading Modes

This paper aims to examine the cyclic behavior of panels in steel moment frame subjected to bidirectional and unidirectional loading and to demonstrate the differences of panel behavior under two loading modes. The specimens were composed of wide-flange beams and square tube columns, and the panel zones were designed to yield before columns and beams. Experimental results showed that specimens subjected to bidirectional loading suffered severe damage, caused by the weld fracture at the corner of panel-to-diaphragm weld, and failed at 0.06 rad and 0.04 rad story drift for specimens with panel aspect ratio of 1.4 and 2.0, respectively. Specimens subjected to unidirectional loading developed a story drift of 0.06 rad without strength reduction. The panels contributed about 60%-80% story drift and dissipated approximately 80% of total input energy. Panels with higher aspect ratio showed smaller plastic shear strength because of the effect of flexural yielding in panels. Moreover, the beams were found to present plastic moments 20%-50% lower than theoretical values, which was attributed to the small panel-to-beam strength ratio.

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A Model of Steel Frame for Simulating Connection Fractures

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.452-453.469 ◽

2010 ◽

Vol 452-453 ◽

pp. 469-472

Author(s):

Hong Bo Liu ◽

Long Jun Xu ◽

Shuang Li ◽

Yong Song Shao

Keyword(s):

Seismic Damage ◽

Steel Frame ◽

Frame Structures ◽

Steel Beams ◽

Northridge Earthquake ◽

Seismic Evaluation ◽

Moment Frame ◽

Steel Moment Frame ◽

Welded Steel ◽

Panel Zone

Following the 1994 Northridge earthquake, widespread damages were discovered in welded steel moment frame buildings. In order to accurately simulate the typical seismic damage of welded steel moment frame structures, a new simplified model is proposed for performing seismic evaluation of welded steel moment frame structures. In this model, the slabs effect is considered, as well as the effects of the slip between slabs and steel beams, deformation of panel zone and connection fractures. Fracture toughness demands were evaluated in terms of the mode I stress intensity factor. The model was employed in simulation of seismic damage of Blue Cross Building which experienced fractured connections in the Northridge earthquake. It indicates that the model can accurately predict the earthquake response of welded steel moment frame structures and estimate the level of damage. The approach proposed in this paper has important meaning to the research on seismic damage of steel frame which may experience fractured connections.

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Effect of panel zone strength ratio on reduced beam section steel moment frame connections

Alexandria Engineering Journal ◽

10.1016/j.aej.2018.07.017 ◽

2018 ◽

Vol 57 (4) ◽

pp. 3523-3533 ◽

Cited By ~ 3

Author(s):

Amr A. Soliman ◽

Omar A. Ibrahim ◽

Abdelaziz M. Ibrahim

Keyword(s):

Strength Ratio ◽

Moment Frame ◽

Steel Moment Frame ◽

Reduced Beam Section ◽

Panel Zone ◽

Beam Section

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Seismic Performance of a Green Roof Structure

Sustainability ◽

10.3390/su13084278 ◽

2021 ◽

Vol 13 (8) ◽

pp. 4278

Author(s):

Svetlana Tam ◽

Jenna Wong

Keyword(s):

Green Roof ◽

Time History ◽

Green Roofs ◽

Moment Frame ◽

Steel Moment Frame ◽

Roof Structure ◽

Nonlinear Time History Analyses ◽

Vegetated Roofs ◽

Nonlinear Time History ◽

The Impact

Sustainability addresses the need to reduce the structure’s impact on the environment but does not reduce the environment’s impact on the structure. To explore this relationship, this study focuses on quantifying the impact of green roofs or vegetated roofs on seismic responses such as story displacements, interstory drifts, and floor level accelerations. Using an archetype three-story steel moment frame, nonlinear time history analyses are conducted in OpenSees for a shallow and deep green roof using a suite of ground motions from various distances from the fault to identify key trends and sensitivities in response.

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