scholarly journals The Reduced-Degree-of-Freedom Model for Seismic Analysis of Predominantly Plan-Symmetric Reinforced Concrete Wall–Frame Building

Buildings ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 372
Author(s):  
Aleš Jamšek ◽  
Matjaž Dolšek
Keyword(s):  
Reinforced Concrete ◽  
Seismic Analysis ◽  
Elastic Beam ◽  
Degree Of Freedom ◽  
Seismic Performance Assessment ◽  
Concrete Wall ◽  
Limit States ◽  
Building Stock ◽  
Frame Building ◽  
Frame Buildings

A reduced-degree-of-freedom (RDOF) model for seismic analysis of predominantly plan-symmetric reinforced concrete (RC) wall–frame buildings is introduced. The RDOF model of the wall–frame building consists of elastic beam–column elements with concentrated plasticity used for simulating cantilever walls and predominantly plan-symmetric RC frame buildings that are represented by the improved fish-bone (IFB) model. In this paper, the capability of the RDOF model is demonstrated for two frame buildings and two wall–frame buildings. The RDOF models were defined directly from the building information model. This is an advantage of RDOF models with respect to single-degree-of-freedom (SDOF) models, while the computational robustness of the RDOF models also makes them attractive for the seismic analysis of building stock. The imposed cyclic displacement analyses conducted for the investigated buildings proved that the condensation of the degrees of freedom for RDOF models was appropriate. Consequently, only minor differences were observed for maximum storey drift IDA curves, maximum storey acceleration IDA curves, and seismic fragility functions for different limit states. However, development is needed to make RDOF models appropriate for preliminary seismic performance assessment of plan-irregular buildings.

scholarly journals Displacement-Based Seismic Assessment of the Likelihood of Failure of Reinforced Concrete Wall Buildings

Buildings ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 295
Author(s):  
Amirhossein Orumiyehei ◽  
Timothy J. Sullivan
Keyword(s):  
Reinforced Concrete ◽  
Seismic Risk ◽  
Concrete Wall ◽  
Limit States ◽  
Simplified Approach ◽  
Performance Based Assessment ◽  
Assessment Approach ◽  
Reinforced Concrete Wall ◽  
Displacement Based ◽  
Assessment Procedures

To strengthen the resilience of our built environment, a good understanding of seismic risk is required. Probabilistic performance-based assessment is able to rigorously compute seismic risk and the advent of numerical computer-based analyses has helped with this. However, it is still a challenging process and as such, this study presents a simplified probabilistic displacement-based assessment approach for reinforced concrete wall buildings. The proposed approach is trialed by applying the methodology to 4-, 8-, and 12-story case study buildings, and results are compared with those obtained via multi-stripe analyses, with allowance for uncertainty in demand and capacity, including some allowance for modeling uncertainty. The results indicate that the proposed approach enables practitioners to practically estimate the median intensity associated with exceeding a given mechanism and the annual probability of exceeding assessment limit states. Further research to extend the simplified approach to other structural systems is recommended. Moreover, the research highlights the need for more information on the uncertainty in our strength and deformation estimates, to improve the accuracy of risk assessment procedures.

scholarly journals Timber frame houses resistant to dynamic loads - seismic analysis

2018 ◽  
Vol 219 ◽  
pp. 01001
Author(s):  
Marcin Szczepański ◽  
Wojciech Migda
Keyword(s):  
Polyurethane Foam ◽  
Considerable Increase ◽  
Seismic Analysis ◽  
Numerical Models ◽  
Mineral Wool ◽  
Seismic Excitations ◽  
Timber Frame ◽  
Frame Building ◽  
Frame Buildings ◽  
Node Displacement

The aim of the article is to present results of seismic analysis results of two real-sized timber frame buildings subjected to seismic excitations. The first model was insulated with mineral wool, the second one with polyurethane foam. Technology and specifications involved in both models construction is based on the previously conducted experimental research on timber frame houses, including wall panels tests, wall numerical models and study on material properties and precisely reflect results of the those research. During the seismic analysis reference node located in buildings were selected. In selected node displacement values were measured and compared between two analyzed models. The results of the numerical analysis presented in the article indicate that the application of polyurethane foam for a skeleton filling of the timber-frame building leads to the increase in stiffness as well as damping of the whole structure, which results in a considerable increase in the seismic resistance of the structure.

Seismic Vulnerability of Existing RC Buildings and Influence of the Decoupling of the Effective Masonry Panels from the Structural Frames

2012 ◽  
Vol 268-270 ◽  
pp. 646-655
Author(s):  
Fabio de Angelis ◽  
Donato Cancellara
Keyword(s):  
Reinforced Concrete ◽  
Seismic Vulnerability ◽  
Seismic Analysis ◽  
Effective Interaction ◽  
Collapse Mechanism ◽  
Limit States ◽  
Capacity Curves ◽  
Masonry Infills ◽  
N2 Method ◽  
Structural Frame

In the present work we discuss on the seismic vulnerability of reinforced concrete existing buildings. In particular we consider a reinforced concrete building originally designed for only gravitational loads and located in a zone recently defined at seismic risk. According to the Italian seismic code NTC 2008 a displacement based approach is adopted and the N2-method is considered for the nonlinear seismic analysis. In the analysis all the masonry infill panels in effective interaction with the structural frame are considered for the nonlinear modeling of the structure. The influence of the effective masonry infills on the seismic response of the structure is analyzed and it is discussed how the effect of the masonry infills irregularly located within the building can give rise to a worsening of the seismic performance of the structure. It is shown that in the present case a not uniform positioning of the masonry infills within the building can give rise to a fragile structural behavior in the collapse mechanism. Furthermore a comparative analysis is performed by considering both the structure with the effective masonry infills and the bare structural frame. For these two structures a pushover analysis is performed, the relative capacity curves are derived and it is shown that fragile collapse mechanisms can occur depending on the irregular positioning of the effective masonry infills. Accordingly it is discussed how in the present case a decoupling of the effective masonry infills from the structural frame can give rise to a smoother response of the capacity curves. For the examined case of an obsolete building with irregular positioning of the masonry panels, the choice of decoupling the effective masonry panels from the structural frame may facilitate the retrofitting strategies for the achievement of the proper safety factors at the examined limit states.

Anti-Seismic Analysis of Masonry-Reinforced Concrete Structure Based on LS-DYNA

2011 ◽  
Vol 99-100 ◽  
pp. 870-874
Author(s):  
Xiao Bin Liu ◽  
Guo Ping Chen
Keyword(s):  
Reinforced Concrete ◽  
Composite Structure ◽  
Seismic Analysis ◽  
Shear Wall ◽  
Masonry Wall ◽  
Reinforced Concrete Structure ◽  
Concrete Wall ◽  
Earthquake Load ◽  
Reinforced Concrete Wall ◽  
Combined Structure

composite structure of masonry wall and reinforced concrete wall as A new type of structure, With masonry structure is adopted for the subject, Proper Settings of reinforced concrete shear wall part of combined structure system, It mainly by shear deformation of masonry and bending deformation of reinforced concrete shear wall is mainly composed LS-DYNA, software of finite element, is used to study the structure, simulations of the response procedures of composite structure under earthquake load are made, as well as the destruction of composite structure. According to calculation and analysis, it can be known that this kind of composite structure can obviously improve seismic resistant capability, and the level of destruction is relative smaller, which can meet the requirements for fortification against earthquake that is "keeping intact in minor earthquakes, repairable in medium earthquakes, standing upright in major earthquakes"

Seismic Vulnerability of Existing RC Buildings and Influence of the Decoupling of the Effective Masonry Panels from the Structural Frames

2012 ◽  
Vol 256-259 ◽  
pp. 2244-2253 ◽  
Author(s):  
Fabio de Angelis ◽  
Donato Cancellara
Keyword(s):  
Reinforced Concrete ◽  
Seismic Vulnerability ◽  
Seismic Analysis ◽  
Effective Interaction ◽  
Collapse Mechanism ◽  
Limit States ◽  
Capacity Curves ◽  
Masonry Infills ◽  
N2 Method ◽  
Structural Frame

In the present work we discuss on the seismic vulnerability of reinforced concrete existing buildings. In particular we consider a reinforced concrete building originally designed for only gravitational loads and located in a zone recently defined at seismic risk. According to the Italian seismic code NTC 2008 a displacement based approach is adopted and the N2-method is considered for the nonlinear seismic analysis. In the analysis all the masonry infill panels in effective interaction with the structural frame are considered for the nonlinear modeling of the structure. The influence of the effective masonry infills on the seismic response of the structure is analyzed and it is discussed how the effect of the masonry infills irregularly located within the building can give rise to a worsening of the seismic performance of the structure. It is shown that in the present case a not uniform positioning of the masonry infills within the building can give rise to a fragile structural behavior in the collapse mechanism. Furthermore a comparative analysis is performed by considering both the structure with the effective masonry infills and the bare structural frame. For these two structures a pushover analysis is performed, the relative capacity curves are derived and it is shown that fragile collapse mechanisms can occur depending on the irregular positioning of the effective masonry infills. Accordingly it is discussed how in the present case a decoupling of the effective masonry infills from the structural frame can give rise to a smoother response of the capacity curves. For the examined case of an obsolete building with irregular positioning of the masonry panels, the choice of decoupling the effective masonry panels from the structural frame may facilitate the retrofitting strategies for the achievement of the proper safety factors at the examined limit states.

scholarly journals A procedure for the analysis and design of ductile reinforced concrete frame buildings of moderate height

1975 ◽  
Vol 8 (4) ◽  
pp. 260-272
Author(s):  
R. L. Williams
Keyword(s):  
Reinforced Concrete ◽  
New Zealand ◽  
Brittle Failure ◽  
Design Approach ◽  
Capacity Design ◽  
Reinforced Concrete Frame ◽  
Analysis And Design ◽  
Concrete Frame ◽  
Frame Building ◽  
Frame Buildings

A procedure is presented in step by step form for designing and detailing a reinforced concrete frame building to the requirements of DZ4203 (Draft New Zealand loading code). Consideration is given for adequate ductility by means of a capacity design approach to all members to obtain a large number of plastic hinges which are detailed to dissipate energy without brittle failure. Further ductile detailing is given for all other locations where accidental hinges could occur and to limit excessive deflections that may result from deterioration of beam column joints.

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