scholarly journals Construction Sequence Analysis and Conventional Lumped Analysis considering P-Delta Effect by Using Etabs

2021 ◽  
Vol 9 (VII) ◽  
pp. 1181-1189
Author(s):  
Shweta S. Bhade
Keyword(s):  
Sequence Analysis ◽  
Response Spectrum ◽  
Response Spectrum Method ◽  
Construction Stage ◽  
Construction Sequence ◽  
Building Frame ◽  
Load Variations ◽  
Spectrum Method ◽  
Negative Moment ◽  
The Stability

While analyzing a multistorey building frame, conventionally all the probable loads are applied after modeling the entire building frame. But in practice the frame is constructed in various stages. Accordingly, the stability of frame varies at every construction stage. Even during construction freshly placed concrete floor is supported by previously cast floor by formwork. Thus, the loads assumed in conventional analysis will vary in transient situation. Obviously, results obtained by the traditional analysis will be unsuitable. Therefore, the frame should be analyzed at every construction stage taking into account variation in loads. The phenomenon known as Construction Sequence Analysis considers these uncertainties precisely. Therefore, the building structure should be analysed at every stage of construction taking into account the load variations. In this project two cases have been considered. Whereas in Case 1 the multistoried building (G+22 storied) with floating columns and transfer girder will be analysed by response spectrum method and considering P-delta effect as a whole for the subjected loading and in Case 2 the multistoried building (G+22storied) with floating columns and transfer girder will be analysed by response spectrum method with reference to the construction sequence or staged construction and considering P-delta effect. In the present study a G+22 storey multistoried R.C.C building model is modelled using Etabs 2019 software. Response spectrum analysis is made by considering building situated in zone III.Building models are analyzed by Etabs 2019 software to study the effect of maximum positive moment, maximum negative moment, maximum shear forces, maximum deflection, maximum torsion moment of transfer girder beam and total axial load under transfer girder and floating column etc

Seismic response analysis of steel–concrete hybrid wind turbine tower

2021 ◽  
pp. 107754632110075
Author(s):  
Junling Chen ◽  
Jinwei Li ◽  
Dawei Wang ◽  
Youquan Feng
Keyword(s):  
Wind Turbine ◽  
Response Spectrum ◽  
Ground Motions ◽  
Time History ◽  
Seismic Action ◽  
Response Spectrum Method ◽  
Spectrum Method ◽  
Wind Turbine Tower ◽  
Ground Types ◽  
Nonlinear Time History

The steel–concrete hybrid wind turbine tower is characterized by the concrete tubular segment at the lower part and the traditional steel tubular segment at the upper part. Because of the great change of mass and stiffness along the height of the tower at the connection of steel segment and concrete segment, its dynamic responses under seismic ground motions are significantly different from those of the traditional steel tubular wind turbine tower. Two detailed finite element models of a full steel tubular tower and a steel–concrete hybrid tower for 2.0 MW wind turbine built in the same wind farm are, respectively, developed by using the finite element software ABAQUS. The response spectrum method is applied to analyze the seismic action effects of these two towers under three different ground types. Three groups of ground motions corresponding to three ground types are used to analyze the dynamic response of the steel–concrete hybrid tower by the nonlinear time history method. The numerical results show that the seismic action effect by the response spectrum method is lower than those by the nonlinear time history method. And then it can be concluded that the response spectrum method is not suitable for calculating the seismic action effects of the steel–concrete hybrid tower directly and the time history analyses should be a necessary supplement for its seismic design. The first three modes have obvious contributions on the dynamic response of the steel–concrete hybrid tower.

Comparative Evaluation of Mode Combination Methods in Seismic Analysis Using Response Spectrum Method for Tank Structure Using FEA - Seismic FEA

2011 ◽  
Vol 110-116 ◽  
pp. 5240-5248
Author(s):  
Sujay Shelke ◽  
H.V. Vankudre ◽  
Vinay Patil
Keyword(s):  
Seismic Analysis ◽  
Response Spectrum ◽  
Initial Step ◽  
Relative Displacement ◽  
Geometrical Parameters ◽  
Response Spectrum Method ◽  
Spectrum Method ◽  
Combination Methods ◽  
Eigen Values ◽  
Modes Of Vibration

Typical seismic analysis using response spectrum method involves several steps from the initial step of extracting the modes. At the initial stage Eigen values are extracted corresponding to the modes of vibration. These give us Eigen vectors which are a series of relative displacement shapes; however these do not correspond to real displacements or stresses. Participation factors asses these Eigen vectors and grades them according to contribution they will have to the overall solution. Based on the spectral seismic acceleration, participation factor is used to calculate the mode coefficient, which is more of a scaling factor to give physical meaning to the values. Once the modes are extracted, the key issue is of combining these modes to obtain the seismic response. The modes cannot be added algebraically in reality as all the modes do not occur at the same time. Hence we employ methods which can add the modes in a more realistic manner. The objective of this paper is to do a comparative study of various mode combination methods with a focus on tank structures and study the effect of various geometrical parameters on the combination methods

A modified response spectrum method based on uniform probability spectrum

2018 ◽  
Vol 17 (2) ◽  
pp. 657-680
Author(s):  
Cheng Su ◽  
Zhijian Huang ◽  
Jianhua Xian
Keyword(s):  
Response Spectrum ◽  
Response Spectrum Method ◽  
Spectrum Method ◽  
Uniform Probability

Research on the Seismic Analysis and Optimization of High Flux Reactor Nuclear Power Piping System Based on Multi-Point Response Spectrum Method

2020 ◽  
Author(s):  
Xuan Huang ◽  
Pingchuan Shen ◽  
Shuai Liu ◽  
Jian Liu ◽  
Xiaozhou Jiang ◽  
...  
Keyword(s):  
Seismic Analysis ◽  
Response Spectrum ◽  
High Flux ◽  
Analysis Method ◽  
Response Spectrum Method ◽  
High Flux Reactor ◽  
Reactor Coolant ◽  
Spectrum Method ◽  
Flux Reactor ◽  
Coolant System

Abstract High flux reactor is an important engineering test reactor, which can be used in irradiation research of materials, chemistry, isotopes, medicine and other fields. In the high flux reactor coolant system, there are a large number of nuclear pipes and the layout is complex. The optimization of seismic analysis method for reactor coolant system is an important part in the design process to ensure the nuclear pipes meet the design specifications. The traditional single point response spectrum method needs to envelope the response spectrum of different floors as the analysis input. This method is difficult to give the reasonable seismic load to the numerous nuclear pipes and it will increase the design cost and the difficulty of safety analysis about nuclear pipe. In this paper, an optimized seismic analysis method of reactor coolant system is proposed. By using the multi-point response spectrum method, the optimization of different excitation loading modes for different constrained support points is realized. The analysis results show that the multi-point response spectrum method can solve the problem that different support points are located at different elevation floors in the reactor coolant system, which makes the calculation results more accurate and reasonable. Compared with the traditional method, it can make the design more efficient and practical.

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