EFFECT OF GRAVITY LOADING ON INELASTIC SEISMIC DEMAND OF STRUCTURES

2012 ◽  
Vol 06 (04) ◽  
pp. 1250022 ◽  
Author(s):  
SEKHAR CHANDRA DUTTA ◽  
RAJIB CHOWDHURY
Keyword(s):  
Axial Force ◽  
Seismic Design ◽  
Axial Load ◽  
Concrete Structures ◽  
Seismic Demand ◽  
Hysteresis Behavior ◽  
Performance Based Seismic Design ◽  
Yield Capacity ◽  
The Impact

Performance based seismic design requires precise assessments of inelastic seismic demand. Often, the studies to assess such demands are made without due cognizance to the impact of axial load caused by gravity. In this paper, the effect of gravity-induced axial force on load resisting members on such demand quantities is examined. To encompass the behavior of steel as well concrete structures with various types of degrading features, four different hysteresis models are used in the study. The results show that the effect of axial force on inelastic seismic demand become more significant for systems with short periods having degrading hysteresis behavior. Neglecting the effect of axial force may lead to an underestimation of yield capacity resulting in an overestimation of demand implying a safer design.

Research Situation on the Performance-Based Seismic Design Method for Reinforced Concrete Structure

2010 ◽  
Vol 163-167 ◽  
pp. 1757-1761
Author(s):  
Yong Le Qi ◽  
Xiao Lei Han ◽  
Xue Ping Peng ◽  
Yu Zhou ◽  
Sheng Yi Lin
Keyword(s):  
Reinforced Concrete ◽  
Seismic Design ◽  
Design Method ◽  
Concrete Structures ◽  
Reinforced Concrete Structures ◽  
Seismic Evaluation ◽  
Seismic Codes ◽  
Performance Based Seismic Design ◽  
Capacity Calculation ◽  
Seismic Design Method

Various analytical approaches to performance-based seismic design are in development. Based on the current Chinese seismic codes，elastic capacity calculation under frequent earthquake and ductile details of seismic design shall be performed for whether seismic design of new buildings or seismic evaluation of existing buildings to satisfy the seismic fortification criterion “no damage under frequent earthquake, repairable under fortification earthquake, no collapse under severe earthquake”. However, for some special buildings which dissatisfy with the requirements of current building codes, elastic capacity calculation under frequent earthquake is obviously not enough. In this paper, the advanced performance-based seismic theory is introduced to solve the problems of seismic evaluation and strengthening for existing reinforced concrete structures, in which story drift ratio and deformation of components are used as performance targets. By combining the features of Chinese seismic codes, a set of performance-based seismic design method is established for reinforced concrete structures. Different calculation methods relevant to different seismic fortification criterions are adopted in the proposed method, which solve the problems of seismic evaluation for reinforced concrete structures.

Preliminary Parametric Assessment of a Bolted Endplate Joint under Combined Axial Force and Cyclic Bending Moment

2011 ◽  
Vol 255-260 ◽  
pp. 718-721
Author(s):  
Z.Y. Wang ◽  
Q.Y. Wang
Keyword(s):  
Finite Element Analysis ◽  
Axial Force ◽  
Seismic Design ◽  
Axial Load ◽  
Failure Modes ◽  
Bending Moment ◽  
Element Analysis ◽  
Cyclic Behaviour ◽  
Joint Behaviour ◽  
Steel Joints

Problems regarding the combined axial force and bending moment for the behaviour of semi-rigid steel joints under service loading have been recognized in recent studies. As an extended research on the cyclic behaviour of a bolted endplate joint, this study is performed relating to the contribution of column axial force on the cyclic behaviour of the joint. Using finite element analysis, the deteriorations of the joint performance have been evaluated. The preliminary parametric study of the joint is conducted with the consideration of flexibility of the column flange. The column axial force was observed to significantly influence the joint behaviour when the bending of the column flange dominates the failure modes. The reductions of moment resistance predicted by numerical analysis have been compared with codified suggestions. Comments have been made for further consideration of the influence of column axial load in seismic design of bolted endplate joints.

The Analysis on Controllability of Angular Ball Bearings with Considering the Installation Errors

2012 ◽  
Vol 217-219 ◽  
pp. 2740-2745 ◽  
Author(s):  
Shu Min Wan ◽  
Jing Huai Li ◽  
Xi Zhi Wu ◽  
Bin Lin
Keyword(s):  
Axial Force ◽  
Axial Load ◽  
Radial Force ◽  
Ball Bearings ◽  
Complex Load ◽  
Bearing Load ◽  
The Impact

A new definition was proposed-bearing control; in the case the bearing subjects to both radial and axial force only, the deformation is roughly symmetry about the Y-axis. When axial preload is 0.4 times greater than radial force, the bearing is controllable. In the case the bearing is exposed to pure torque and axial load, and axial preload is 50 times of the torque, the bearing is controllable. When complex load is applied on the bearing and axial preload is more than 0.418Fr+0.46Fa, the bearing is controllable. The application of spring equivalent bearing to simplify the model; the analysis of the impact on bearing exerted by a variety of installation errors and determination of the best installation form; the relation between installation errors and bearing load, and the relation between axial preload and the best installation form under the condition that the bearing is controllable, all of those are mentioned.

Seismic Performance Spectra

2010 ◽  
Vol 163-167 ◽  
pp. 443-453
Author(s):  
Wen Feng Liu ◽  
Xing Pan Fu
Keyword(s):  
Seismic Performance ◽  
Seismic Design ◽  
Response Spectra ◽  
Seismic Demand ◽  
Three Dimension ◽  
Seismic Demands ◽  
Performance Objective ◽  
Objective Performance ◽  
Performance Based Seismic Design ◽  
Ground Motion Records

The seismic performance spectrum is a new kind of the response spectra which is formed according to the designated performance objectives. The performance objectives are changed according to the performance objective level and period of structure, and are different in the acceleration sensitive, velocity sensitive and displacement sensitive range in the seismic performance spectrum. The seismic performance spectrum formulas are derived, which demonstrate the mathematic relationship between the seismic demands of the different performance objective levels and the period of structure. The fitted formulas of the seismic performance spectra for seismic design are obtained due to statistical result of 1085 ground motion records. The new seismic performance spectra are shown in visual three-dimension figures which can represent the seismic demand, performance objective and period of structure in this paper. The philosophy of the seismic performance spectrum is analyzed which reveals the rules for estimating seismic demand of structure at the different performance objective levels. So the multi-objective performance-based seismic design is also proposed using the seismic performance spectrum.

The Impact of Infilled Wall on Seismic Performance of Frame Structure

2013 ◽  
Vol 353-356 ◽  
pp. 2127-2130
Author(s):  
Xi Ping Liu
Keyword(s):  
Seismic Performance ◽  
Seismic Design ◽  
Quantitative Description ◽  
Frame Structure ◽  
Frame Structures ◽  
Current Phase ◽  
Seismic Design Code ◽  
Performance Based Seismic Design ◽  
The One ◽  
The Impact

In accordance with damages of infilled wall frame structures in Wenchuan earthquake, the current 2010 version of "Seismic Design Code of Building" is attached herewith increasing significance to infilled wall, which switches "consider the impact of infilled wall on seismic performance of frame structure and avoid main structure destruction caused by setting infilled wall unreasonably " from a general provision into a mandatory provision, however, a specific quantitative description on the impact of infilled wall on seismic performance of frame structure is still absent. The impact of infilled wall on seismic performance of frame structure is analyzed in the paper, and two suggestions pertain to design and research of infilled wall is proposed under current phase: on the one hand, "conceptual design" should be kept on highlighting in the seismic design of infilled wall frame structures; on the other hand, based on the concept of "performance-based seismic design", the idea that infilled wall should be treated distinctively is put forward.

scholarly journals Seismic Acceleration and Displacement Demand Profiles of Non-Structural Elements in Hospital Buildings

Buildings ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 243
Author(s):  
Giammaria Gabbianelli ◽  
Daniele Perrone ◽  
Emanuele Brunesi ◽  
Ricardo Monteiro
Keyword(s):  
Seismic Design ◽  
Response Spectra ◽  
Relative Displacement ◽  
Seismic Demand ◽  
Structural Elements ◽  
Practical Application ◽  
Absolute Acceleration ◽  
Floor Response Spectra ◽  
Performance Based Seismic Design ◽  
Definition Of

The importance of non-structural elements in performance-based seismic design of buildings is presently widely recognized. These elements may significantly affect the functionality of buildings even for low seismic intensities, in particular for the case of critical facilities, such as hospital buildings. One of the most important issues to deal with in the seismic performance assessment of non-structural elements is the definition of the seismic demand. This paper investigates the seismic demand to which the non-structural elements of a case-study hospital building located in a medium–high seismicity region in Italy, are prone. The seismic demand is evaluated for two seismic intensities that correspond to the definition of serviceability limit states, according to Italian and European design and assessment guidelines. Peak floor accelerations, interstorey drifts, absolute acceleration, and relative displacement floor response spectra are estimated through nonlinear time–history analyses. The absolute acceleration floor response spectra are then compared with those obtained from simplified code formulations, highlighting the main shortcomings surrounding the practical application of performance-based seismic design of non-structural elements. The absolute acceleration floor response spectra are then compared with those obtained from simplified code formulations. The results, both in terms of absolute acceleration and relative displacement floor response spectra, highlighted the influence of the higher modes of the structure and the inaccuracy of the code provisions, pointing out the need for more accurate simplified methodologies for the practical application of performance-based seismic design of non-structural elements.

scholarly journals Deflection Calculation Based on SDOF Method for Axially Loaded Concrete-Filled Steel Tubular Members Subjected to Lateral Impact

2020 ◽  
Vol 2020 ◽  
pp. 1-16
Author(s):  
Luming Wang ◽  
Yanhui Liu ◽  
Jiahuan Song ◽  
Shichun Zhao ◽  
Zhe Wang ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Axial Force ◽  
Calculation Method ◽  
Axial Load ◽  
Impact Force ◽  
Great Influence ◽  
Lateral Impact ◽  
Simulation Accuracy ◽  
Axially Loaded ◽  
The Impact

Axial force has a great influence on the dynamic behavior and the impact resistance of concrete-filled steel tubular (CFST) members. Based on numerical simulation and theoretical analysis, the impact response and deflection calculation method for axially loaded CFST members subjected to lateral impact are investigated in this paper. The nonlinear numerical model of an axially loaded CFST member considering the strain rate effects has been established, and the simulation accuracy has been validated by comparing with existing test results. The contrastive investigation is carried out to illustrate the influence of axial load on the variation pattern of impact force for CFST members under various structural and impact parameters, and its result indicates that the impact force-time histories for CFST members with different axial loads are mainly characterized by rectangular pulse and triangular pulse. Moreover, a simplified calculation method considering the effect of axial force is proposed based on the equivalent single degree of freedom (SDOF) method, devoted to predicting the deflection of axially loaded CFST members subjected to lateral impact. The comparisons with the numerical simulation prove that the deflection calculation method has a reasonable accuracy; thus, the proposed method can be utilized in the damage assessment and anti-impact design for CFST members subjected to lateral impact and axial load.

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