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

Author(s):  
Muhammad Habib

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.

2010 ◽  
Vol 163-167 ◽  
pp. 2176-2180
Author(s):  
Yang Wen ◽  
Fei Zhou

In the article based on the geometric characteristics of the tower and force characteristics, the author designs the concrete-filled steel tube (CFST) 3 limbs column tower, and establishes finite element model of the tower. We carry on time history analysis of the concrete-filled steel tubular wind turbine tower based on finite element method when the earthquake wave is different. Under rare earthquake, the majority bars of the concrete-filled steel tube 3 limbs column tower are in the elastic stage, only a small number of bars in the top and the bottom are into the plastic phase. The post-seismic displacement at the top of tower is 1.1m which is slightly less than the tower height of 1 / 50 (1.26m) and meets the seismic requirements of the region. The analytical result may provide the foundational test data and advice for the design of the CFST wind turbine tower.


2020 ◽  
Vol 10 (2) ◽  
pp. 85
Author(s):  
Muhammad Habib ◽  
Naik Muhammad ◽  
Saeedullah Jan Mandokhail ◽  
Zafar Baloch ◽  
Muhammad Irfan ◽  
...  

Author(s):  
Nabila Huda Aizon ◽  
Azlan Adnan ◽  
Mohd Zamri Ramli ◽  
Norazah Arjuna ◽  
Asmawisham Alel ◽  
...  

2011 ◽  
Vol 2011 ◽  
pp. 1-23 ◽  
Author(s):  
Sanaz Mahmoudpour ◽  
Reza Attarnejad ◽  
Cambyse Behnia

Analysis and design of structures subjected to arbitrary dynamic loadings especially earthquakes have been studied during past decades. In practice, the effects of soil-structure interaction on the dynamic response of structures are usually neglected. In this study, the effect of soil-structure interaction on the dynamic response of structures has been examined. The substructure method using dynamic stiffness of soil is used to analyze soil-structure system. A coupled model based on finite element method and scaled boundary finite element method is applied. Finite element method is used to analyze the structure, and scaled boundary finite element method is applied in the analysis of unbounded soil region. Due to analytical solution in the radial direction, the radiation condition is satisfied exactly. The material behavior of soil and structure is assumed to be linear. The soil region is considered as a homogeneous half-space. The analysis is performed in time domain. A computer program is prepared to analyze the soil-structure system. Comparing the results with those in literature shows the exactness and competency of the proposed method.


2014 ◽  
Vol 919-921 ◽  
pp. 1039-1042
Author(s):  
Liang Lv ◽  
Bin Liang ◽  
Wen Sheng Wang

Seismic displacement response of cable stayed bridge without back stays was studied in this paper. Based on the cable stayed bridge without back stays on Zhenshui Road in Xinmi City, finite element method (FEM) was applied to calculate and analyze natural vibration and peak displacement response of the structure. The results show that with regard to mid-span and consolidation of pier and main tower, uniaxial seismic wave input results in peak displacement response of corresponding direction is bigger than that of any other direction. Peak displacement response of the top of the main tower is bigger than those of mid-span and consolidation of pier and main tower in any seismic wave input cases, which indicates that the top of the tower needs to be focused in the process of design and construction. Seismic wave along triaxial direction has the biggest impact on the structure. Keywords: cable stayed bridge without back stays; seismic displacement response; seismic wave input; peak displacement response


Author(s):  
Srihari Palli ◽  
Raghuveer Dontikurti ◽  
Rakesh Chandmal Sharma ◽  
Neeraj Sharma

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.


2020 ◽  
Vol 20 (07) ◽  
pp. 2071006
Author(s):  
Jin Zhang ◽  
Zejun Han ◽  
Hongyuan Fang ◽  
Linqing Yang

The interaction between underground pipelines and soils is crucial to the design and maintenance of underground pipeline network systems. In this paper, the dynamic stiffness matrix in the frequency-domain of the buried pipeline is obtained by the improved scaled boundary finite element method (SBFEM) coupled with the finite element method (FEM) at the interface between the far and near fields. A new coordinate transformation together with a scaled line is introduced in the improved SBFEM. Combined with the mixed variable algorithm, the time-domain solution of the buried pipeline under dynamic loads is then obtained. The accuracy of the proposed algorithm was verified by numerical examples. A parametric study is performed to assess the influence of the anisotropic characteristics of the layered soils on the dynamic response of the pipeline, the result of which provides a reliable basis for engineering practice. The results show that these parameters have a significant impact on the pipeline. The understanding of this impact can contribute to the design, construction, and maintenance of the corresponding engineering projects.


Author(s):  
Jong-Sung Kim ◽  
Suk-Hyun Lee ◽  
Hyeong Do Kweon

In this study, effect of analysis variables on structural integrity of nuclear piping under beyond design basis earthquake was investigated via performing dynamic time history seismic analysis. A finite element model of the piping system such as shut-down cooling line was developed combining solid and beam elements. Dynamic time history analysis was performed via finite element elastic plastic stress analysis. Validity of the dynamic time history analysis procedure was verified via comparing with the previous study results. Finally, the effect of analysis variables such as finite element characteristics, transition length between elbow and straight line, fluid effect, etc. was investigated via performing parametric dynamic time history seismic analysis. As a result, it was found that use of the 1st incompatible element is recommended, the transition length is the same as curvature of the elbow, and fluid has to be considered.


Author(s):  
Lingyu Sun ◽  
Weiwei Chen ◽  
Xiaojie Wang ◽  
Ning Kang ◽  
Bin Xu ◽  
...  

The present paper studied the dynamic response of an underwater system with its navigation plate rotated relative to the main body until it was blocked by an energy absorber. In this process, the relation between fluid-driving moment and speed of main body, as well as the relation between rotation angle of the plate and design parameters of absorber, was investigated through combined finite element method and finite volume method. Before the plate contacted with the energy absorber, it was modeled by linear elastic material, the movement process was solved by finite volume method with dynamic boundary. When the plate started to contact and crash with the absorber, it was modeled by elastic-plastic material, and the interaction of fluid-structure coupling was simulated by explicit finite element method in LSDYNA and finite volume method in FLUENT. The two-way data exchange on the interface between fluid and structure was carried out through equivalent force and moment on each patch of the interface. In addition, the simulation accuracy on large plastic deformation of absorber was verified through a group of drop hammer experiments. After the energy absorber was crushed to ultimate shape, the open angle of plate reached the maximum value and the plate kept relative static to the rigid body. The maximum structural stress and deformation, the opening time and angle of the plate were evaluated by numerical method. It is demonstrated that the proposed method can effectively predict the dynamic response of underwater system under impact loads, and both the absorption capability of the block and the speed of moving body affect the dynamic response history and structural safety.


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