scholarly journals Numerical Simulations to Predict the Seismic Performance of a 2-Story Steel Moment-Resisting Frame

Materials ◽  
2020 ◽  
Vol 13 (21) ◽  
pp. 4831
Author(s):  
Roberto Tartaglia ◽  
Mario D’Aniello ◽  
Raffaele Landolfo
Keyword(s):  
Numerical Simulations ◽  
Seismic Performance ◽  
Plastic Hinge ◽  
Seismic Intensity ◽  
Steel Moment Frame ◽  
Shake Table Tests ◽  
Ongoing Research ◽  
Ductility Demand ◽  
Steel Moment Resisting Frames ◽  
Moment Resisting

The seismic response of steel moment resisting frames (MRFs) is influenced by the behavior of joints. Within the ongoing research project “FUTURE”(Full-scale experimental validation of steel moment frame with EU qualified joints and energy efficient claddings under Near fault seismic scenarios), shake table tests will be carried out on a two-story one bay MRF equipped with different types of prequalified beam-to-column joints. In order to design the experimental campaign, preliminary numerical simulations have been carried out to predict the seismic performance of the experimental mock-up in terms of distribution of damage, transient and residual interstory drifts. In this paper the main modeling assumptions and the results of the seismic analyses are shown and discussed. In particular, the response of joints was systematically investigated by refined finite element (FE) simulations and their behavior was taken into account in the global structural performance by means of both concentrated plastic hinge and distributed plasticity models. Both static and dynamic non-linear analyses show in which terms the type of models for plastic hinges influences the results. The modeling approach plays a key role only at very high seismic intensity where large ductility demand is imposed. In addition, changing the type of joints has less influence on the overall response of the frame.

Predicted Ductility Demands for Steel Moment Resisting Frames

1989 ◽  
Vol 5 (2) ◽  
pp. 409-427 ◽  
Author(s):  
Charles W. Roeder ◽  
James E. Carpenter ◽  
Hidetake Taniguchi
Keyword(s):  
United States ◽  
Seismic Design ◽  
The United States ◽  
Structural Systems ◽  
Ductility Demand ◽  
Steel Moment Resisting Frames ◽  
The Past ◽  
Moment Resisting Frames ◽  
Column System ◽  
Moment Resisting

Recent changes to the United States seismic design provisions permit the use of weak column-strong beam steel moment resisting frames. This design concept has not been used in the past, because it results in plastic hinges in the columns during moderate or extreme earthquakes. This paper shows the results of inelastic dynamic response calculations on a weak column frame and a comparable strong column system. The results show that the ductility demand is much greater for the weak column strong beam framing system with some acceleration records. The required ductility is then compared for the different structural systems and both are compared to the results of experiments. The comparison suggests that the weak column system may not be able to develop the required ductility. The results of this paper should help define the viability and limits in applicability of the weak column system.

Seismic Fragility Analysis of MRFs with PR Bolted Connections Using IDA Approach

2018 ◽  
Vol 763 ◽  
pp. 678-685 ◽  
Author(s):  
Emanuele Brunesi ◽  
Roberto Nascimbene ◽  
Gian Andrea Rassati
Keyword(s):  
Three Dimensional ◽  
Seismic Intensity ◽  
Structural Safety ◽  
Damage State ◽  
Steel Moment Resisting Frames ◽  
Existing Structures ◽  
Moment Resisting ◽  
Damage States ◽  
Structure Height ◽  
Partially Restrained

Partially restrained (PR) bolted beam-to-column connections are a promising typology of connection in modern steel moment resisting frames (MRFs). Both high-fidelity three-dimensional solid models and mechanics-based idealisations have been extensively explored in order to investigate the behaviour of this attractive solution, applicable both to new construction and to retrofitting of existing structures. Despite this, structural safety has been probabilistically assessed and controlled in a relatively few cases, thus neglecting characterisation, modelling and propagation of uncertainties. As such, this paper moves from a deterministic to a probabilistic framework, proposing fragility models at multiple damage states for low-and medium-rise MRF structures with T-stub and top-and-seat angle connections which may be applied for seismic risk assessment and management. After validation against past experimental data, use was made of component-based modelling to reproduce the seismic response of these PR bolted connection systems within planar MRFs designed for earthquake resistance in accordance with current European rules. A set of 44 records scaled at increasing seismic intensity was considered to perform a series of incremental dynamic analyses (IDAs). Fragility functions for each damage state of interest were then derived and compared. The analysis results show the influence of connection typology and structure height.

scholarly journals Performance-Based Multiobjective Optimal Seismic Retrofit Method for a Steel Moment-Resisting Frame Considering the Life-Cycle Cost

2014 ◽  
Vol 2014 ◽  
pp. 1-14 ◽  
Author(s):  
Hyo Seon Park ◽  
Dong Chul Lee ◽  
Byung Kwan Oh ◽  
Se Woon Choi ◽  
Yousok Kim
Keyword(s):  
Seismic Performance ◽  
Life Cycle Cost ◽  
Optimization Technique ◽  
Seismic Retrofit ◽  
Seismic Damage ◽  
Damage Cost ◽  
Pareto Solution ◽  
Steel Moment Resisting Frames ◽  
Moment Resisting Frames ◽  
Moment Resisting

This study proposes a performance-based multiobjective optimization seismic retrofit method for steel moment-resisting frames. The brittle joints of pre-Northridge steel moment-resisting frames are retrofitted to achieve ductility; the method involves determining the position and number of connections to be retrofitted. The optimal solution is determined by applying the nondominated sorting genetic algorithm-II (NSGA-II), which acts as a multiobjective seismic retrofit optimization technique. As objective functions, the initial cost for the connection retrofit and lifetime seismic damage cost were selected, and a seismic performance level below the 5% interstory drift ratio was employed as a constraint condition. The proposed method was applied to the SAC benchmark three- and nine-story buildings, and several Pareto solutions were obtained. The optimized retrofit solutions indicated that the lifetime seismic damage cost decreased as the initial retrofit cost increased. Although every Pareto solution existed within a seismic performance boundary set by a constraint function, the seismic performance tended to increase with the initial retrofit cost. Analysis and economic assessment of the relations among the initial retrofit cost, lifetime seismic damage cost, total cost, and seismic performance of the derived Pareto solution allow building owners to make seismic retrofit decisions more rationally.

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