Numerical investigation on dynamic response of a steel lattice tower under various seismic events

2019 ◽  
Author(s):  
Tomasz Falborsk ◽  
Natalia Lasowicz
Keyword(s):  
Dynamic Response ◽  
Soil Structure ◽  
Numerical Study ◽  
Soft Soil ◽  
Time History ◽  
Time History Analysis ◽  
Modal Parameters ◽  
History Analysis ◽  
Lattice Tower ◽  
Ground Motion Records

The present paper presents the results of the numerical study designed to investigate the soil-structure flexibility effects on modal parameters (i.e. fundamental frequencies) and time-history analysis response (represented by the top relative displacements) of a 46.8 m high steel lattice tower subjected to a number of ground motions including also one mining tremor. In addition to the fixed-base condition, three different soil types (i.e. dense soil, stiff soil, and soft soil) were considered in this investigation. Site conditions were characterized by their average effective profile velocities, Poisson’s ratios, and finally mass densities. Soil-foundation flexibility was introduced using the spring-based approach, utilizing foundation springs and dashpots. The first step was to investigate the influence of different base conditions on modal parameters of the steel lattice tower. In the final part of the current study time-history analysis was performed using different two-component ground motion records (in two horizontal, mutually perpendicular directions). The results obtained indicate that modal parameters and dynamic response of the structure may be considerably affected by the soil-structure interaction effects. Therefore, the present paper confirms the necessity of utilizing soil-flexibility into numerical research.

Analysis of Dynamic Response of a Railway Locomotive Using ANSYS

2021 ◽  
Vol 13 (2) ◽  
Author(s):  
Srihari Palli ◽  
Raghuveer Dontikurti ◽  
Rakesh Chandmal Sharma ◽  
Neeraj Sharma
Keyword(s):  
Dynamic Response ◽  
Time History ◽  
Time History Analysis ◽  
Surface Irregularity ◽  
Transient Dynamic Analysis ◽  
Element Analysis ◽  
Car Body ◽  
History Analysis ◽  
Track Surface ◽  
General Time

Transient dynamic analysis (sometimes called time-history analysis) is a technique used to determine the dynamic response of a structure under the action of any general time-dependent loads. The time scale of the loading is such that the inertia or damping effects are considered to be important. Present work is focused on performing the time history analysis of a typical locomotive coach using finite element analysis in Indian railroad conditions. Track surface irregularity in the form of an ellipsoidal bump is modelled with assumptions that the vehicle passes over the bump in 0.144 seconds, variation in displacement at different key locations of the truck and car body models is plotted against time under standard loading conditions. The response pattern of the front and rear portions of the locomotive truck and car body indicate that these locations are more susceptible to wheel excitations compared to that of the centre portions of it as they are away from the centre of gravity of the vehicle due to unbalanced mass distribution.

Analysis of Seismic Dynamic Response of Tunnel in Karst Areas

2011 ◽  
Vol 90-93 ◽  
pp. 2108-2111
Author(s):  
Lin Jie Chen ◽  
Bo Liang ◽  
Zhi Yong Wang
Keyword(s):  
Dynamic Response ◽  
Soil Structure ◽  
Interaction Model ◽  
Time History ◽  
Side Wall ◽  
Internal Force ◽  
Dynamic Responses ◽  
Karst Caves ◽  
History Analysis ◽  
Karst Areas

Based on soil-structure interaction model, the seismic dynamic response of tunnel in karst areas were performed by using viscous-spring artificial boundary and time history analysis method. In combination with the Menglian tunnel engineering on the Bao-Teng Highway in Yunnan, in different sizes and sites karst caves conditions, the dynamic responses of displacement and internal force on control points of the tunnel structure were obtained. The results show that comparatively large interal forces, under the high-intensity earthquake conditions, will appear on the side wall of the tunnel which through karst areas, less ones on arch crown and inverted arch parts, and the differential displacements of arch crown reach to the maximum. When the karst caves are located in the side of the tunnel, it make the seismic dynamic response get more large, which make the surrounding rock must be strengthened treatment. The results provide useful reference for the aseismatic design of tunnel.

scholarly journals Dynamic Response of Symmetric and Asymmetric Setback Buildings

2020 ◽  
Vol 9 (4) ◽  
pp. 3179-3183
Keyword(s):  
Dynamic Response ◽  
Transverse Direction ◽  
Dynamic Behaviour ◽  
Time History ◽  
Longitudinal Direction ◽  
Time History Analysis ◽  
Seismic Excitations ◽  
Numerical Studies ◽  
History Analysis ◽  
Codal Provisions

Numerical studies have been carried out to study the dynamic behaviour of a five-storey regular building, symmetric setback and asymmetric setback buildings having three bays along longitudinal direction and one bay along transverse direction. The objective of the study is to compare the irregularity indices with respect to different codal provisions such as IS:1893-2016, Euro Code 8-2004 and ASCE 7.05-2005 as well as with the expressions proposed by Karavasilis et al. (2008), and Pradip sarkar et al.(2010). These buildings are subjected to seismic excitations with time history analysis and the response parameters such as fundamental period of vibration of the structures, displacements and storey drifts were evaluated

scholarly journals Performance-based seismic assessment of vulnerability of dam using time history analysis

2018 ◽  
Vol 149 ◽  
pp. 02035
Author(s):  
Oumnia Elmrabet ◽  
Hasnae Boubel ◽  
El Mehdi Echebba ◽  
Mohamed Rougui ◽  
Ouadia Mouhat
Keyword(s):  
Soil Structure ◽  
Seismic Vulnerability ◽  
Seismic Analysis ◽  
Time History ◽  
Time History Analysis ◽  
Seismic Assessment ◽  
Assessment Procedure ◽  
Ground Acceleration ◽  
History Analysis ◽  
Al Hoceima

The current performance-based seismic assessment procedure can be computationally intensive as it requires many time history analyses (THA) each requiring time intensive post-processing of results. Time history analysis is a part of structural analysis and is the calculation of the response of a structure to any earthquake. It is one of the main processes of structural design in regions where earthquakes are prevalent. The objective of this study is to evaluate the seismic performance of embankment dam located on the Oued RHISS in the Province of AL HOCEIMA using the THA method. To monitor structural behavior, the seismic vulnerability of structure is evaluated under real earthquake records with considering the soil-structure-fluide interaction. In this study, a simple assistant program is developed for implementing earthquake analyses of structure with ANSYS, ground acceleration–time history data are used for seismic analysis and dynamic numerical simulations were conducted to study and identify the total response of the soil-structure system.

Numerical Simulation on the Overall Dynamic Response of One High-Rise Steel Frame

2012 ◽  
Vol 204-208 ◽  
pp. 1215-1219
Author(s):  
Dai Guo Chen ◽  
Yong Yao ◽  
Hai Jun Wang ◽  
Yong Jun Deng ◽  
Jing Zhou
Keyword(s):  
Dynamic Response ◽  
Spectrum Analysis ◽  
Time History ◽  
Time History Analysis ◽  
Steel Frame ◽  
Mode Analysis ◽  
Seismic Action ◽  
Modal Shape ◽  
High Rise ◽  
History Analysis

Using the finite element analysis software ANSYS to analyze the overall dynamic response of one specific high-rise steel-frame,including modal analysis, spectrum analysis and time-history analysis. Then do a comparative analysis with the results of calculation by the professional software PKPM. As the results: the structural calculation can use layer model; Larger mutations appeared in the stress of weak-story and the relevant story need to reinforce or set up supports under the anti-seismic design in the elastic time-history analysis of structure; Y-direction translation is preferentially happened in first order modal shape and lateral-torsional coupling happened in third order modal shape among the vibration mode analysis; The response spectrum analysis of frequent earthquake show that seismic action is more serious in ground layer.

scholarly journals Seismic Analysis for Multi-Story Building Horizontally Damped Above Basement Level

2018 ◽  
Vol 7 (2.29) ◽  
pp. 955
Author(s):  
Mohammed Ziauddin Patowary ◽  
Abdul Kadir Marsono
Keyword(s):  
Seismic Analysis ◽  
Numerical Study ◽  
Time History ◽  
Seismic Energy ◽  
Ground Level ◽  
Time History Analysis ◽  
Base Shear ◽  
History Analysis ◽  
Natural Time ◽  
Story Building

Due to the urbanization multi-story building with underground story for parking space and storage are very common in practice. Now a day, seismic energy dissipating devices are being used for various types of structures and located in basements which are difficult to maintain.  The main objective is to evaluate the effectiveness of horizontal dampers in the ground floor level of the multi-story building above basement. Among different types of dampers, visco-elastic [VE] dampers are used for this numerical study. Comparing with other types of passive energy dissipating devices, visco-elastic [VE] dampers are considered most suitable. For the better understanding of the effectiveness of horizontal dampers, stiff foundation system is considered thus soil-structure interaction is omitted. In this numerical study, seismic response of different hypothetical structures analyzed having different underground stories and horizontal dampers only in the ground level. Modeling and analysis of the structures and installation of the dampers are done by using finite element modeling software [ETABS]. Time history analysis was used to simulate the response of the structures. Sabah earthquake [05/June/2015] with the PGA of 0.126g was used for the time history analysis. Different dynamics parameters such as natural time period, displacement, base shear and inter-story drift were evaluated. Changes in the results among the structures demonstrated the efficiency of horizontal dampers. Optimum locations of the horizontal dampers were also revealed in this study in the basis of the analysis results.  

scholarly journals Optimizing Parameters for Anticollision Systems between Adjacent Buildings under Earthquakes

2018 ◽  
Vol 2018 ◽  
pp. 1-10
Author(s):  
Nan Jin ◽  
Yong-qiang Yang
Keyword(s):  
Time History ◽  
Time History Analysis ◽  
Consumption Ratio ◽  
Adjacent Buildings ◽  
Optimum Parameters ◽  
History Analysis ◽  
Energy Consumption Ratio ◽  
Ground Motion Records ◽  
Ratio Energy ◽  
Selection Of

Adjacent buildings with anticollision system would have the possibility of pounding under earthquake if there is insufficient separate distance between the two buildings. The effect of pounding and earthquake characters on the optimum parameters for anticollision system is studied through time-history analysis method in this paper. Interstory displacement ratio, energy consumption ratio, and the total strain energy of the two buildings are considered as control variables. The results show that the pounding between adjacent buildings will reduce the range of optimum parameters, and earthquake characters also have effect on the selection of optimum parameters. Therefore, it is strongly recommended to input more than three ground motion records for a time-history analysis to get the optimum parameters considering the effect of pounding and earthquake characters.

Seismic Zonation and Default Suite of Ground-Motion Records for Time-History Analysis in the North Island of New Zealand

2012 ◽  
Vol 28 (2) ◽  
pp. 667-688 ◽  
Author(s):  
Claudio A. Oyarzo-Vera ◽  
Graeme H. McVerry ◽  
Jason M. Ingham
Keyword(s):  
New Zealand ◽  
Ground Motion ◽  
Time History ◽  
Time History Analysis ◽  
Seismic Zonation ◽  
The North ◽  
History Analysis ◽  
Ground Motion Records ◽  
Site Classes ◽  
Selection Of

A seismic zonation to be used in the selection of ground-motion records for time-history analysis of buildings in the North Island of New Zealand is presented. Both deaggregations of the probabilistic seismic hazard model and the seismological characteristics of the expected ground motions at different locations were considered in order to define the zonation. A profile of the records expected to apply within each zone according to the identified hazard scenarios is presented and suites of records are proposed for each zone, based on region-wide criteria, to be used in time-history analysis in the absence of site specific studies. A solution for structures with fundamental periods of between 0.4 and 2.0 seconds is proposed, considering a 500-year return period and two common site classes (C and D, according to the New Zealand Loadings Standard).

scholarly journals Dynamic Response Study of a Single Tower Cable Stayed Bridge using Finite Element Method

2020 ◽  
pp. 85-92
Author(s):  
Muhammad Habib
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Dynamic Response ◽  
Vertical Direction ◽  
Time History ◽  
Time History Analysis ◽  
Cable Stayed Bridge ◽  
History Analysis ◽  
Cable Stayed Bridges ◽  
Element Method

Cable stayed bridges are most widely used in the modern medium to long bridge construction due to their efficient response, economic viability, faster construction, and eye-catching aesthetics. The dynamic response of a single tower cable stayed bridge is studied by performing both nonlinear static and dynamic analyses using finite element method based software ANSYS. A three dimensional bridge model was developed using ANSYS. The steel cables were simulated using a single element approach to minimize the time and data use. Due to the complexity of cable stayed bridges, it is tried to avoid the convergence problems by adopting the displacement convergence approach. The bridge exhibits complex modal shapes due to the coupling effects for the free vibrations. The response of the bridge in vertical direction is more elastic and flexible as compared to the longitudinal and transverse direction. Response of the critical sections of girder, tower, and cables was also studied by time-history analysis using the ground acceleration data of the EI-Centro 1940 earthquake. A 10 second ground data with 0.0001 second time step was used. It was observed that stiffness in the vertical direction is a key player in the dynamic behavior of the cable stayed bridge. The response of the right and left span is similar which adds to the accuracy of the analysis. Time history analysis of the bridge shows that the largest displacements or peak responses are not related to the peak ground accelerations, rather they are dependent on many other factors like bridge stiffness, nature of the earthquake ground excitations and mass distribution. However, the results show the general trend of cable stayed bridges.

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