Study on Long Span Transmission Tower’s Typical Malfunctions

2011 ◽  
Vol 464 ◽  
pp. 187-190
Author(s):  
Hai Lin Wang ◽  
Qiang Gao
Keyword(s):  
Finite Element ◽  
Atmospheric Corrosion ◽  
Finite Element Models ◽  
Foundation Settlement ◽  
Transmission Tower ◽  
Long Span ◽  
Material Stiffness ◽  
Long Time

In this paper, several typical malfunctions of the long span transmission tower are analyzed, such as the material stiffness reduced by atmospheric corrosion over a long time, the loose of bolt joint caused by accidental factors or man-made sabotages, and foundation settlement. And establish finite element models according to the characteristics of different malfunctions. By analyzing the models, we discuss the safety of the long span transmission tower at different malfunctions. It is shown that the proposed method is of efficiency and practicality.

scholarly journals Study on the Old Girders in the Widening Hollow Slab Girder Bridge

2018 ◽  
Vol 38 ◽  
pp. 03028
Author(s):  
Ying Wang ◽  
Li Fang Zhang ◽  
Hai Yan Ma
Keyword(s):  
Finite Element ◽  
Construction Project ◽  
Internal Force ◽  
Finite Element Models ◽  
Foundation Settlement ◽  
Bridge Structure ◽  
Girder Bridges ◽  
Vehicle Load ◽  
Girder Bridge

Taking the bridge widening project of Shanghai-Hangzhou-Ningbo expressway widening construction project (China) as the background in this paper, the variation law of the internal force of the old bridge in the widening hollow slab girder bridge under vehicle load is studied, which is under the condition of different span lengths and different widening widths. Three different span lengths of the pre-tensioned prestressed hollow slab girder bridges are selected, the spatial finite element models of both the old bridge and the whole structure of widening bridge are established and calculated respectively by Midas/Civil software. The influences of widening and load increasing on the old bridges under the vehicle load are compared and analyzed. In addition, the authors also analyze the influences of different widening widths on the force state of old bridges under the condition of widening the same number of lane. Moreover , the effects on the old bridges that are caused by the uneven foundation settlement of widening bridge structure are also studied in this paper. This paper can provide some references for widening design of hollow slab bridges.

Multi-Tower Effect Analysis of Long-Span Suspension Bridge

2010 ◽  
Vol 163-167 ◽  
pp. 1940-1944
Author(s):  
Xiao Yan Zheng ◽  
Zhuo De Feng ◽  
Yue Xu
Keyword(s):  
Finite Element ◽  
Natural Frequency ◽  
Bending Moment ◽  
Suspension Bridge ◽  
Finite Element Models ◽  
Performance Difference ◽  
Displacement Effect ◽  
Effect Analysis ◽  
Long Span ◽  
Behavior Study

As a new bridge system, mechanics behavior study on long-span multi-tower suspension is also very deficiency. The existence of center towers is the origin of performance difference between multi-tower suspension bridge and the traditional one. Based on the Midas/Civil platform, the paper takes a three tower suspension bridge as project reference, establishes finite element models of suspension bridge, which the main span is longer than one kilometer and towers from two to seven. Moreover, the structural property is analyzed separately, which bending moment and displacement effect of girder and tower along with the tower number changes is considered. Natural frequency differences of the model bridges are also paid attention on.

Finite-Element Solution of Elastic-Plastic Boundary-Value Problems

1981 ◽  
Vol 48 (1) ◽  
pp. 69-74 ◽  
Author(s):  
J. H. Prevost ◽  
T. J. R. Hughes
Keyword(s):  
Finite Element ◽  
Boundary Value Problems ◽  
Plastic Material ◽  
Finite Element Models ◽  
Element Solution ◽  
Elastic Plastic ◽  
Material Stiffness ◽  
Integration Techniques ◽  
Elastic Plastic Material ◽  
Selective Integration

It is demonstrated that elastic-plastic failure states may be captured in finite-element models by employing (1) the elastic-plastic material stiffness to form the global stiffness, (2) reduced/selective integration techniques to alleviate mesh “locking” due to incompressibility, and (3), in the case of symmetrical configurations, an imperfection in the form of a weak element.

Dynamic Response analysis of Long Span Transmission Tower under Tornado

2012 ◽  
Vol 450-451 ◽  
pp. 1257-1260
Author(s):  
Qiang Gao ◽  
Chao Ren ◽  
Yang Xu ◽  
Zhen Yao Liu
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Dynamic Response ◽  
Dynamic Analysis ◽  
Wind Direction ◽  
Response Analysis ◽  
Transmission Tower ◽  
Dynamic Response Analysis ◽  
Long Span ◽  
Element Method

To study the effects of tornado on long span transmission tower, a model of the tower is built and the features of the tornado are considered. Three different wind cases are discussed in dynamic analysis with finite element method. The analysis results show that dynamic response is more significant at 45° wind direction.

scholarly journals Inhomogeneous dielectrics: conformal mapping and finite-element models

Open Physics ◽  
2017 ◽  
Vol 15 (1) ◽  
pp. 839-844 ◽  
Author(s):  
Eugenio Costamagna ◽  
Paolo Di Barba
Keyword(s):  
Finite Element ◽  
Finite Difference ◽  
Domain Boundary ◽  
Dielectric Materials ◽  
Finite Element Models ◽  
Second Stage ◽  
Inhomogeneous Dielectric ◽  
Long Time ◽  
Relevant Field

AbstractField singularities in electrostatic and magnetostatic fields require special attention in field calculations, and today finite element methods are normally used, both in homogeneous and in inhomogeneous dielectric cases. Conformal mappings are a traditional tool in the homogeneous case, but two-stage Schwarz-Christoffel + Finite Difference procedures have been proposed for a long time to solve problems in case of inhomogeneous dielectric materials too. This allowed to overcome accuracy problems caused by convex corners in the domain boundary and relevant field singularities, and to easily apply finite difference (FD) solvers in rectangular domains. In this paper, compound procedures Schwarz-Christoffel + Finite Elements Method procedures are suggested, to improve both the accuracy and the speed of second stage calculations. The results are compared to Schwarz-Christoffel + Finite Difference and to direct finite-element calculations, and the small differences analyzed considering a well know case study geometry,i.e., a shielded dielectric-supported stripline geometry.

Influence of Stiffness Weakening at Construction Joints on the Deflection of Cantilevering-Cast Prestressed Concrete Box Girder

2015 ◽  
Vol 777 ◽  
pp. 34-37
Author(s):  
Hong Jiang Li
Keyword(s):  
Finite Element ◽  
Prestressed Concrete ◽  
Joint Stiffness ◽  
Finite Element Models ◽  
Box Girder ◽  
Long Span ◽  
Stiffness Reduction ◽  
Rigid Frame ◽  
Concrete Box Girder ◽  
Girder Bridge

For a long-span prestressed concrete box-girder bridge erected by the double-cantilever segmental method, concrete of segmental joints and concrete in their nearby area may be different from integrally-cast concrete in structural performances. For example, the stiffness of segmental joints could be weakened significantly. To reveal influences of weakening in the stiffness of segmental joints on the deflection at mid-span of box girder, a typical continuous rigid frame bridge in China was taken as the analysis example, and its finite element models were established. In these models, weakening joints were simulated. After the validity of finite element models were warranted, the deflection in the completed construction stage and the long-term deflection in the running period of box girder were calculated, and then the variation of these deflections with the stiffness reduction in all segmental joints was described. Results showed that, compared with the shearing stiffness reduction in segmental joints, the bending stiffness reduction played more significant role in affecting the deflection of box girder. When the weakening times of joint stiffness arrived at 100, deflection values of the box girder increased significantly. However, in the practical engineering, the determination of stiffness reduction in segmental joints according by their damages, and the incorporation of weakening segmental joints into the bearing capacity assessment for existing box girders were all worth further study.

The Finite Element Models for the Built Ting Kau Bridge

2011 ◽  
Vol 52-54 ◽  
pp. 794-799
Author(s):  
Rui Juan Jiang
Keyword(s):  
Finite Element ◽  
Health Monitoring ◽  
Bridge Deck ◽  
Heavy Traffic ◽  
Vertical Plane ◽  
Finite Element Models ◽  
Grid Model ◽  
Long Span ◽  
Cable Forces ◽  
Inclined Planes

The Ting Kau Bridge in Hong Kong is a cable-stayed bridge comprising two main spans and two side spans. The bridge deck is supported by three towers, an end pier and an abutment. Each of the three towers consists of a single reinforced concrete mast which reduces its section in steps, and it is strengthened by transverse cables and struts in the transverse vertical plane. The bridge deck is supported by four inclined planes of cables emanating from anchorages at the tower tops. In view of the heavy traffic on the bridge, and threats from typhoons and earthquakes originated in areas nearby, the dynamic behaviour of long-span cable-supported bridges in the region is always an important consideration both in their design and health monitoring. This paper describes the development of the 3D grid model for the structural health monitoring of the bridge. The 3D grid model is intended to form the backbone of subsequent multi-scale finite element models for bridge rating. The baseline model is built up and calibrated to match the bridge geometry and cable forces specified on the as-built drawings. The modelling of the concrete deck in the simplified grid model is an important issue as it has great effect on the lateral and torsional vibrations of the bridge. This paper examines in particular the shear lag effect on the modelling strategy.

Study on the Arc-Cable Supported Long Span Spatial Structure of Erdos Dong-Sheng Stadium

2012 ◽  
Vol 433-440 ◽  
pp. 1836-1839 ◽  
Author(s):  
Zai Gen Mu ◽  
Jian Xiao ◽  
Yin Lan Shen ◽  
Zhong Fan
Keyword(s):  
Finite Element ◽  
Spatial Structure ◽  
Project Design ◽  
Finite Element Models ◽  
Long Span ◽  
Type Selection

This paper has introduced rational arch axis and built finite element models for the analysis of arch axis type selection, based on the retractable roof of Ordos Dong-sheng stadium under actual loads. And the approximation optimum method is used in adjustment of rational arch axis of the stadium's giant arch. At last, this paper supplies some references for this project design.

Effect of the Dynamic Characteristic of Long-Span Transmission Tower on High Voltage Transmission Line

2014 ◽  
Vol 687-691 ◽  
pp. 3423-3426 ◽  
Author(s):  
Xiao Dong Feng ◽  
Feng Ren Fu ◽  
Tong Chen Miao ◽  
Yong Xing Lai ◽  
Xian Fa Wang
Keyword(s):  
Transmission Line ◽  
Dynamic Characteristics ◽  
Transmission Lines ◽  
Finite Element Models ◽  
Transmission Tower ◽  
Line System ◽  
High Voltage Transmission Line ◽  
Long Span ◽  
Set Up ◽  
Engineering Practices

In this paper, according to the structure character of transmission tower, the transmission lines are simulated as link10 space spar elements which have the unique feature of a bilinear stiffness matrix resulting in a uniaxial tension-only (or compression-only) elements and the transmission tower are simulated as space element beam188 and link 8. So the ANSYS fine finite element models of transmission tower-line system which are more agrees with engineering practices are set up, dynamic characteristics are calculated on nine conditions and the influences of transmission line on dynamic characteristics of the transmission tower are discussed, some valuable conclusions are given.

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