Author: A. D. BartonPublisher:
ISBN:
Category : Dwellings
Languages : en
Pages : 226
Book Description
Performance of Domestic Cold-formed Steel Frames when Subjected to Earthquake Loading
Author: A. D. BartonPublisher:
ISBN:
Category : Dwellings
Languages : en
Pages : 226
Book Description
Performance Evaluation of Cold-formed Steel Braced Frames for Seismic Loads
Author: Moon Sung LeePerformance of Steel Framed Domestic Structures Subjected to Earthquake Loads
Author: Andrew David BartonPublisher:
ISBN:
Category : Building, Iron and steel
Languages : en
Pages : 754
Book Description
Proceedings of the 11th International Conference on Behaviour of Steel Structures in Seismic Areas
Author: Federico M. MazzolaniPublisher: Springer Nature
ISBN: 3031628888
Category :
Languages : en
Pages : 1034
Book Description
Seismic Performance of Steel Moment Frames Plastically Designed by Least Squares Stress Fields
Author: Kenichi OhiPublisher:
ISBN:
Category : Earthquake resistant design
Languages : en
Pages : 106
Book Description
Investigation of the Performance of Steel Frames Under Earthquake Loads Incorporating Energy Dissipating Systems
Author: Tasiopoulos KonstantinosPublisher:
ISBN:
Category :
Languages : en
Pages : 280
Book Description
Performance Evaluation of Steel Buckling Restrained Braced Frames Subjected to Far-Field, Near-Field, and Long-Duration Earthquakes
Author: Fokruddin AhmadPublisher:
ISBN:
Category : Earthquake engineering
Languages : en
Pages : 0
Book Description
The use of Buckling Restrained Brace Frames (BRBFs) has been increasing in recent decades due to their ability to provide superior seismic performance and enhance the resilience of buildings against earthquakes. However, not many studies have extensively and thoroughly investigated the response and resiliency of prescriptively designed BRBF buildings to varying types of earthquake hazards. This study fills that research gap by investigating the seismic performance of two code-designed BRBFs prototype buildings subjected to far-field, near field with pulse and without pulse, and long-duration ground motion sets. The first phase of the study investigated the seismic resiliency of the prescriptively designed BRBF buildings and compared them to identical prototypes designed with mass timber PT-CLT rocking walls using the FEMA P-58 methodology to compare seismic losses. The seismic loss investigation was part of a larger study evaluating the two types of structural systems using multiple criteria decision analysis across four performance categories of seismic resiliency, global warming potential, superstructure cost, and durability. The global warming potential and superstructure cost estimate was completed by others, but this study completed the seismic resiliency assessment and multiple criteria decision analysis.The second phase of this dissertation work analyzed the structural response of the two BRBF prototype buildings across four sets of ground motions representing different hazard levels in Seattle, WA. The two prototype buildings were modeled in 3D using OpenSeesPy to understand the effect of different ground motion types on the structural responses. The analysis results showed that near-field motions increase the deformation demands, such as inter-story drift and maximum ductility in the pulse direction. Though BRBFs are not a self-centering systems, only the upper two floors of the mid-rise building experienced residual drift higher than 0.2%, which is the threshold for expecting minor repair and structural realignment. None of the stories had residual inter-story drift exceeding 0.5% drift for any motion sets. Overall, the code minimum based BRBF buildings showed excellent performance across all the different hazard types. However, the one caveat of this analysis was that long-duration motions had significantly higher cumulative ductility demand than other motion sets.Therefore, the final phase of this dissertation works further investigated the cumulative deformation demand on BRBF braces under long-duration motions. It is important to verify the ductility of the braces through analysis or testing because they act as the primary structural fuse to dissipate the earthquake energy. The final study compared different loading protocols from different countries to the nonlinear modeling results of long-duration motions. It was determined that the long duration motions had over 80% probability of exceeding the current AISC 341 required testing protocol. To rectify these issues, a new loading protocol appropriate for long-duration earthquakes was proposed that accounts for the increased plastic deformation demand and matches the cyclic content of the nonlinear dynamic analyses.In conclusion, these studies have demonstrated that prescriptively designed BRBFs that meet code minimum requirements are a high performing lateral force resisting system to a range of earthquake hazards. They have excellent seismic resiliency, even when not optimized during design through nonlinear time history analysis, as is common in performance-based earthquake engineering. Additionally, the code-designed BRBF buildings were not predicted to have high residual inter-story drifts, which means they are highly likely to be repairable with minor adjustments and re-alignment. However, it was identified that long-duration earthquakes will increase the ductility demand on the braces significantly compared to far-field and near-field earthquakes and that current minimum testing requirements do not account for this increase. A new protocol was proposed to rectify this one challenge with BRBFs.
Structural Performance of Cold-formed Steel Frame with Bolted Moment Connections
Author: Bayan Anwer AliPublisher:
ISBN:
Category : Building, Iron and steel
Languages : en
Pages : 0
Book Description
Metals Abstracts
Author: Earthquake-induced Collapse of Steel Moment Resisting Frames with Conventional and High Performance Steel Columns
Author: Yusuke SuzukiPublisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
"Capacity design principles have reduced the earthquake-induced collapse risk in steel frame buildings designed in seismic regions. Experiments suggest that the steel column behaviour may be significantly compromised due to member and local geometric instabilities, thereby increasing the associated collapse risk and likelihood of building demolition due to residual deformations. The High Yield Point (HYP400) steel is a steel material that has a higher yield stress and notch toughness but less strain hardening than conventional mild steels. HYP400 steel could enhance capacity design principles, such as the strong-column-weak-beam (SCWB) ratio when they are utilized in steel columns and potentially increase the collapse capacity of steel moment resisting frames (MRFs) under earthquake shaking. This thesis advances the state-of-knowledge through a multi-scale (from material to system) level study to assess the potential use of high-performance steel materials in minimizing earthquake-induced collapse of steel MRFs. The primary focus is on the characterization of the collapse behaviour of HYP400 and conventional steel hollow square section (HSS) columns by means of experimental testing and corroborating numerical simulations. Dual-parameter collapse-consistent loading histories (i.e., axial load and lateral drift demands) are developed to better quantify the flexural and axial demands in both interior and end columns in steel MRFs. These protocols reflect the asymmetric drifting of a building in one primary loading direction prior to dynamic instability ("ratcheting"). They also reflect the seismic demands imposed into steel columns within a steel MRF subjected to near-fault and long-duration ground motions. A landmark experimental program is conducted that characterizes the collapse behaviour of wide-flange and HSS steel columns under cyclic loading. The experimental program highlights the differences in the seismic demands and failure modes observed in steel columns depending on the imposed lateral and axial loading history, expected ground motion characteristics and building topology. It is shown that column axial shortening dominates the steel column stability. The hysteretic behaviour of HSS steel columns is further evaluated through corroborating finite element (FE) simulations. The steel column pre- and post-buckling behaviour is fully characterized depending on the type of steel material including the HYP400 steel. The FE results provide insight on the main differences of the lateral and axial damage progression between interior and end columns within the same steel MRF bay. The experimental data and corroborating finite element studies provide the basis for the development of a versatile steel column deterioration model that can explicitly simulate the axial-bending interaction, the column axial shortening due to local buckling induced softening and the cyclic deterioration in the column's strength and stiffness. Local buckling-induced softening is modeled through the development of an equivalent stress-strain formulation that includes a softening branch and can be fully characterized through conventional stub column tests. System level dynamic collapse simulation studies are conducted with over 80 archetype buildings with steel MRF systems ranging from 2 to 12-stories. Emphasis is placed on the importance of column axial shortening on the seismic performance of steel MRFs. It is shown that depending on the ground motion type, column axial shortening may result into slab tilting and catenary action prior to collapse. It is also shown that the use of the HYP400 steel columns can potentially enhance the collapse capacity of steel MRFs and reduce the expected residual lateral and vertical deformations in the aftermath of earthquakes." --