Impact of Damping Scaling Factors on Direct Displacement-Based Design

2016 ◽  
Vol 32 (2) ◽  
pp. 843-859 ◽  
Author(s):  
Cuiyan Kong ◽  
Mervyn J. Kowalsky
Keyword(s):  
Response Spectra ◽  
Equivalent Linearization ◽  
Base Shear ◽  
Limit States ◽  
Scaling Factors ◽  
Equivalent Viscous Damping ◽  
Direct Displacement Based Design ◽  
Displacement Response Spectra ◽  
Performance Limit States ◽  
Displacement Based

Damping scaling factors (DSFs) play an important role in direct displacement-based design (DDBD) as they provide a means to establish displacement response spectra for damping values beyond 5%. Response spectra for multiple damping values are needed for DDBD as the approach relies on equivalent linearization, expressed in the form of effective stiffness and equivalent viscous damping, to establish design forces for prescribed performance limit states. In the past, DSFs based on the Eurocode have been employed for DDBD; however, recent research has resulted in more robust DSF models. This paper examines the accuracy of the current DSF equation used in DDBD across the parameters that are important for structural design. A nonlinear regression analysis is performed based on the data obtained by the Rezaeian et al. (2014) model, and a base shear adjustment factor (SAF) is proposed for application to the DDBD base shear equation.

scholarly journals Nonlinear Static and Dynamic Analysis of Rocking Masonry Corners Using Rigid Macro-Block Modeling

2019 ◽  
Vol 19 (11) ◽  
pp. 1950137 ◽  
Author(s):  
Claudia Casapulla ◽  
Linda Giresini ◽  
Luca Umberto Argiento ◽  
Alessandra Maione
Keyword(s):  
Central Italy ◽  
Response Spectra ◽  
Limit States ◽  
Static And Dynamic Analysis ◽  
Macro Block ◽  
Displacement Response Spectra ◽  
Rocking Motion ◽  
Static Approach ◽  
Nonlinear Static ◽  
Displacement Based

The corner failure is one of the most typical local mechanisms in masonry buildings vulnerable to earthquakes. The seismic assessment of this mechanism is poorly studied in the literature and in this paper it is addressed by means of both nonlinear static and dynamic analyses of rocking rigid blocks. The static approach is based on the displacement-based method and is aimed at predicting the onset of the 3D failure mechanism and its evolution through incremental kinematic analysis. This approach also considers the presence of a thrusting roof and the stabilizing contribution of frictional resistances exerted within interlocked walls. The capacity in terms of both forces and displacements is compared with the seismic demand through the construction of acceleration–displacement response spectra, with some originality. The nonlinear dynamic approach is based on the seminal Housner’s work on rocking rigid blocks and considers the influence of transverse walls, roof overloads and outward thrust, all included in an updated equation of one-sided motion. In particular, the process of defining an equivalent prismatic block, representative of the original corner geometry, is presented to convert the 3D dynamic problem into a 2D rocking motion. The wide suitability and advantage of such modeling approaches to assess the seismic response of rocking masonry structures with reference to specific limit states are demonstrated through a real case study, i.e. the collapse of a corner in a masonry school building during the 2016–2017 Central Italy seismic sequence. The compared results provide a good agreement of predictions in terms of both onset and overturning conditions, for which the static model appears to be more conservative than the dynamic one.

PERPETUATE Project: The Proposal of a Performance-Based Approach to Earthquake Protection of Cultural Heritage

2010 ◽  
Vol 133-134 ◽  
pp. 1119-1124 ◽  
Author(s):  
Sergio Lagomarsino ◽  
Hormoz Modaressi ◽  
Kiriazis Pitilakis ◽  
Vlatko Bosiljkov ◽  
Chiara Calderini ◽  
...  
Keyword(s):  
Cultural Heritage ◽  
Seismic Risk ◽  
Seismic Analysis ◽  
Destructive Testing ◽  
Limit States ◽  
European Guidelines ◽  
Construction Knowledge ◽  
Performance Limit States ◽  
Displacement Based ◽  
Artistic Assets

The paper describes the methodology proposed in the PERPETUATE Project (funded by the Seventh Framework Programme – Theme ENV.2009.3.2.1.1). The methodology proposed in PERPETUATE uses a displacement-based approach for the vulnerability evaluation and design of interventions. The use of safety verification in terms of displacement, rather than strength, orients to new strengthening techniques and helps in the comprehension of interaction between structural elements and unmovable artistic assets. The procedure is based on the following fundamental steps: definition of performance limit states, specific for the cultural heritage assets (considering both structural and artistic assets); evaluation of seismic hazard and soil-foundation interactions; construction knowledge (non-destructive testing, material parameters, structural identification); development of structural models for the seismic analysis of masonry structures and artistic assets and design of interventions; application and validation of the methodology to case studies. Two main scales are considered: the seismic risk assessment at territorial scale and at the scale of single historic building or artistic assets. The final aim of the project is to develop European Guidelines for evaluation and mitigation of seismic risk to cultural heritage assets.

scholarly journals Force Based Design and Direct Displacement Based Design for Dual System Structure

2019 ◽  
Vol 19 (3) ◽  
pp. 162
Author(s):  
Annisaa Dina Puspita ◽  
Anis Rosyidah
Keyword(s):  
Shear Force ◽  
Damage Control ◽  
Performance Level ◽  
Dual System ◽  
Reinforcement Ratio ◽  
System Structure ◽  
Building Structures ◽  
Base Shear ◽  
Direct Displacement Based Design ◽  
Displacement Based

The Force Based Design (FBD) and the Direct Displacement-Based Design (DDBD) are methods for designing seismic-resistant buildings. Building structures designed, are expected to be suitable with the purpose and usefulness of a building. For this reason, this study compares the performance of dual system structures using the DDBD and FBD methods that aim to prove better performance with consideration of safety against users during an earthquake. This research method uses design analysis method to compare the value of the base shear force, reinforcement ratio, and performance level using software for static nonlinear pushover analysis. The results showed the value of the base shear force x direction of the DDBD method was 17.57% smaller than the FBD method, whereas for the y direction the DDBD value was greater than 9.38% of the FBD. The value of the reinforcement ratio of the beam, column and shear wall results is greater DDBD than FBD. The actual drift of the DDBD and FBD methods is slightly different. So that both are at the same level of performance, namely damage control. The performance level has not reached the performance target of life safety design in DDBD, but the structure has met the level performance requirements for offices.

scholarly journals Comparative Study of Direct Displacement Based and Forced Based Design Method for RC- Frame with Shear Wall

10.29007/lft5 ◽  
2018 ◽  
Author(s):  
Bijal Chaudhri ◽  
Dipali Patel
Keyword(s):  
Seismic Design ◽  
Design Method ◽  
Shear Wall ◽  
Performance Based Design ◽  
Rc Frame ◽  
Base Shear ◽  
Global Parameter ◽  
Direct Displacement Based Design ◽  
Moment Resisting ◽  
Displacement Based

The Seismic design of structure has conventionally been force based. Displacement is the major factor for the damage rather than force. The alternative procedure for seismic design, which becomes more popular, is performance based design method. Displacement is global parameter of performance based design method. Direct displacement based design method has been used for seismic design of structure. The paper attempts to design moment resisting RC-frame using Displacement based design method and Forced based design method. 15-storey building with shear wall has been taken for parametric study. The parameter like base shear and lateral load distribution are taken for the study. It is observed that base shear of RC building calculated by DDBD is less compared to FBD.

An Anomaly in the Equivalent Linearization Approach for the Estimation of Inelastic Response

2014 ◽  
Vol 30 (2) ◽  
pp. 965-972 ◽  
Author(s):  
Vijay Namdev Khose ◽  
Yogendra Singh
Keyword(s):  
Dynamic Analysis ◽  
Nonlinear Dynamic ◽  
Nonlinear Response ◽  
Nonlinear Dynamic Analysis ◽  
Response Spectra ◽  
Equivalent Linearization ◽  
Attractive Alternative ◽  
Inelastic Response ◽  
Inelastic Displacement ◽  
Displacement Based

The estimation of inelastic displacement is an essential step in displacement-based design. Estimation of inelastic response using response spectra is a simpler and attractive alternative to nonlinear dynamic analysis. A number of methods based on different approaches are now available to estimate nonlinear response from design spectra. Equivalent linearization is one of the widely used approaches for this purpose. The approach is known to yield reasonably accurate results. However, an anomaly in the approach is observed, which results in significantly non-conservative estimates of inelastic displacement, particularly in displacement-controlled spectral range. This paper illustrates the anomaly using displacement modification factors and numerical examples of oscillators of different periods and ductility. The results from the equivalent linearization approach have been compared with the results of nonlinear dynamic analysis and yield spectrum approach.

A Direct Displacement-Based Design Method Based on Chinese Code of Base Isolated Structures

2011 ◽  
Vol 255-260 ◽  
pp. 2555-2559
Author(s):  
Zhen Sun ◽  
Wei Qing Liu ◽  
Shu Guang Wang ◽  
Ding Zhou ◽  
Dong Sheng Du
Keyword(s):  
Seismic Isolation ◽  
Design Method ◽  
Response Spectrum ◽  
Base Shear ◽  
Direct Displacement Based Design ◽  
High Intensity Zone ◽  
Lead Rubber Bearings ◽  
Displacement Based ◽  
Rubber Bearings ◽  
Relationship Of

A simple and efficient direct displacement-based design (DDBD) method is introduced to base isolated (BI) structures. Assuming the vibration mode of superstructure to be the shear type and considering the BI structure to be an equivalent single degree of freedom (ESDOF) system with spring and damper at the seismic isolation layer. The acceleration response spectrum in Chinese code is converted to displacement response spectrum. Corresponding to the design displacement, the equivalent period is obtained. The relationship of the deign displacement, equivalent period, equivalent stiffness and base shear of the system can be derived from the given formulations. Then, the distribution of the base shear along the floors is obtained. This method has been applied to the design of a 12-story BI structure with lead rubber bearings in high intensity zone in Suqian city, Jiangsu province. The results show that the method is feasible for the design of BI structures.

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