Estimating structural damage of steel moment frames by Endurance Time method

2008 ◽  
Vol 64 (2) ◽  
pp. 145-155 ◽  
Author(s):  
H.E. Estekanchi ◽  
K. Arjomandi ◽  
A. Vafai
Keyword(s):  
Structural Damage ◽  
Moment Frames ◽  
Steel Moment Frames ◽  
Endurance Time ◽  
Endurance Time Method

scholarly journals Evaluating Performance of Concrete Special Moment Resisting Frames with Different Seismic Coefficients Using Endurance Time Method

2018 ◽  
Vol 4 (1) ◽  
pp. 93 ◽  
Author(s):  
Hadi Radmanesh ◽  
Majid Mohammadi
Keyword(s):  
Performance Level ◽  
Cost Ratio ◽  
Optimum Structure ◽  
Moment Frames ◽  
Endurance Time ◽  
Lower Weight ◽  
Seismic Coefficient ◽  
Endurance Time Method ◽  
Moment Resisting ◽  
Real Earthquake

This performance-based study was conducted to investigate the effects of seismic coefficients on performance of concrete special moment frames of 5,7, and 10-storey buildings located in Tehran, Iran. The structures are designed three-dimensionally by ETABS 2016 software according to ACI-318-08. Fifteen specimens were designed with different base shears having seismic coefficients of 0.7, 0.85, 1, 1.15, and 1.30 times the proposed value of Iranian Standard 2800, (i.e. decreased by 70 and 85%, and increased by 115 and 130%). Endurance time method (ETA20in series of ET acceleration function) as well as three real earthquake records was employed to evaluate the seismic performance of the modeled structures. The performance of structures was compared by the time of the first plastic hinges formation in beams and columns, the time of entering to nonlinear region and the time of experiencing storey drift of 2% corresponding to the life safety performance level. It was observed that the results of ET records and real records were similar to each other. A procedure was proposed for finding optimum structure with lower weight using ET method through defining efficient ratio (ER) and cost ratio (CR). Based on the results of ER/CR ratio and considering the importance of collapse prevention performance level, optimum structure was a 7-storey structure with lower weight or cost whose seismic coefficient had been reduced by 70%. It was concluded that high safety can not be achieved simply by increasing the seismic coefficient of structures.

The Morgan Hill Earthquake of April 24, 1984—Performance of Three Engineered Structures

1985 ◽  
Vol 1 (3) ◽  
pp. 579-593 ◽  
Author(s):  
Simin Naaseh
Keyword(s):  
Structural Damage ◽  
Shear Walls ◽  
Lateral Load ◽  
San Jose ◽  
Moment Frames ◽  
Steel Moment Frames ◽  
Long Period ◽  
Steel Building ◽  
Engineered Structures ◽  
Different Characteristics

The performance of three engineered buildings in San Jose during the 1984 Morgan Hill earthquake is reviewed. The lateral-load-resisting systems for these buildings are: (1) concrete shear walls, (2) concrete shear walls and moment frames in two orthogonal directions, and (3) perimeter steel moment frames. The concrete buildings performed satisfactorily with no damage. The steel building oscillated for a long period of time with low damping. There was some nonstructural and content damage and very limited structural damage to this building. The recorded responses of these buildings also showed excitations from two events with different characteristics.

Seismic Energy Demands in Steel Moment Frames

2016 ◽  
Vol 847 ◽  
pp. 210-221
Author(s):  
Selcuk Dogru ◽  
Bora Aksar ◽  
Bulent Akbas ◽  
Jay Shen ◽  
Onur Seker ◽  
...  
Keyword(s):  
Ground Motion ◽  
Structural Damage ◽  
Seismic Energy ◽  
Degree Of Freedom ◽  
Nonlinear Time History Analysis ◽  
Input Energy ◽  
Moment Frames ◽  
Steel Moment Frames ◽  
Energy Parameters ◽  
Energy Demands

This study presents an energy approach to the seismic evaluation of steel moment resisting frames. A structure subjected to strong ground motion is supposed that it shows nonlinear behavior. Energy parameters is a way to specify the structural damage. Input energy is depend on the characteristics of the structure and ground motion. Structural design can be defined as the equilibration of the input energy and the energy dissipation capacity of the structure. Structures subjected to eartquake are supposed to dissipate all the input energy. Studies based on energy concepts are usually applied to single-degree-of-freedom (SDOF) system. For multi-degree-of-freedom (MDOF), more researches and new simpler methodologies are still needed in performance based evaluation including energy parameters. In this study , low – medium and high rise steel moment frames and will be studied in linear and nonlinear time history analysis. The results obtained from these analysis are reviewed for seismic energy demands.

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.

Sign in / Sign up

Export Citation Format

Share Document