scholarly journals SHM System and a FEM Model-Based Force Analysis Assessment in Stay Cables

Sensors ◽  
2021 ◽  
Vol 21 (6) ◽  
pp. 1927
Author(s):  
Jan Biliszczuk ◽  
Paweł Hawryszków ◽  
Marco Teichgraeber

The Rędziński Bridge in Wrocław is the biggest Polish concrete cable-stayed bridge. It is equipped with a large structural health monitoring (SHM) system which has been collecting the measured data since the bridge opening in the year 2011. This paper presents a comparison between the measured data and the finite element method (FEM) calculations, while taking into account 7 years of data collection and analyses. The first part of this paper concerns the SHM application. In the next part, which contains comparisons between forces in cables and temperature changes throughout the structure, the measured data are presented. The third part includes SHM-based calculations and simulations with a complex FEM model to check the measured data and to estimate future measurements. The last part contains a durability assessment calculation for the cable stays.

Author(s):  
Jan Biliszczuk ◽  
Paweł Hawryszków ◽  
Marco Teichgraeber

<p>Over the last 20 years big bridges in Poland have been built and equipped in Structural Health Monitoring systems (SHM). One of those objects is the Rędziński Bridge in Wrocław. It is a cable-stayed concrete bridge built along the motorway A8 in 2011. Since this time the SHM has been collecting data from 222 installed sensors. The bridge is outstanding because of its unusual structure: two separate concert box girders are suspended to a single pylon. The connection is made of 160 stay cables – so this is also the most sensitive part of the structure.</p><p>The first part of the paper concerns the SHM application. In the next part the measured data form the period 2011-2017 are presented, containing comparisons between forces in cables and temperature changes in the whole structure. The third part will include SHM based calculations and simulations with a complex FEM model, to check the measured data and to estimate future measurements. The last part contains the durability assessment calculation for the cable stays.</p>


2021 ◽  
Author(s):  
Jan Biliszczuk ◽  
Maciej Hildebrand ◽  
Marco Teichgraeber ◽  
Hanna Onysyk

<p>Monitoring systems have given the possibility of varied and long-term observation of bridge structures. The paper prestents the analysis of temperature impact on various bridge elements. The data comes from three different large bridges in Poland, equipped with extensive monitoring systems, namely from an arch bridge in Puławy (built in 2008), cable-stayed bridge in Płock (built in 2005) and the cable-stayed bridge in Wrocław (built in 2011). After few years of observation an enormous and valuable database of measured parameters was stored. The analysis shows how temperature changes between individual bridge components (e.g. between decks, pylon and stay cables) affect the structure mechanical behaviour and whether the influence fulfil the standards’ recommendations. Due to various static schemes and materials used in the described bridges, individual and non-typical impact of thermal loads is expected.</p>


Author(s):  
Olivier Boujard ◽  
Ste´phane Pernot ◽  
Alain Berlioz ◽  
Claude Lamarque

Recent experimental campaigns led on the Iroise cable stayed bridge near Brest, France, revealed repeated vibratory events in some cable stays likely to provoke durability problems. A spectral analysis emphasized two regimes in which either the fundamental or the third cable mode were excited. Yet, wavelet scalograms of tests allowed to exhibit a global pylon mode excited by traffic environment through deck-cable-tower interaction and which again excites local cable modes by means of a nonlinear parametric resonance mechanism with vertical bending modes of the girder. Preliminary results are introduced as an attempt to explain such a scenario.


2010 ◽  
Vol 456 ◽  
pp. 23-35 ◽  
Author(s):  
Yan Li ◽  
Da Gang Lv ◽  
Hong Fei Sheng

The existent studies on cable stays fatigue for the serviced cable-stayed bridge generally only considered traffic or wind load action respectively. The long span cable-stayed bridges are very sensitive to wind load, so the fatigue estimation of cable stays considering traffic and wind load simultaneously is very important for the bridge safety. In the present research, taking an actual bridge as an example, based on linear cumulative damage theory, fatigue reliability of cable stays is analyzed under combined load of vehicles and wind. Firstly, based on the long-term traffic survey and wind speed data, traffic and wind load probability distribution models for the bridge are built respectively. Secondly, an intensive computational work is performed to obtain stress time history of the stay cables in the typical time block by running self-compiled Bridge-Vehicle-Wind interaction dynamic response analysis program. Thirdly, the stress result is updated in accordance with traffic growth and extreme wind speed changing in service period. The stress amplitude and frequency are attained by rain-flow cycle counting method. Finally, the fatigue damage limit state function of cable stays is proposed based on linear cumulative damage theory, and solved by Monte-Carlo method. The analysis result shows that the effect of buffeting wind load on the fatigue reliability of cable stays is significant, the influence degree increases generally in accordance with the order from short cable to long cable. The fatigue life of cable under designed safety probability reduces by the range from 2% to 63%, average 50% compared to only considering traffic load. So fatigue assessment of stay cables should take traffic and wind loads together into account. The proposed analysis framework offers a referenced fatigue assessment approach for conventional long span bridges.


2011 ◽  
Vol 295-297 ◽  
pp. 1230-1235
Author(s):  
Jiang Bo Sun ◽  
Zuo Zhou Zhao ◽  
Hong Hua Zhao

This paper presents several methods usually used for measuring cable tension in cable-stayed bridges, especially frequency vibration method. Taken two different length stay-cables under given tension forces in a real cable-stayed bridge as an example, different modeling methods in finite element methods (FEM) were used to solve their natural vibration frequencies. The results by FEM were compared with those from other available theoretical predicting method. It was found that FEM based on tightening string model is more suitable for a long stay-cable. For a short stay-cable under given tension force, beam bending stiffness can be ignored in predicting its first five natural frequencies using a hinged beam model in FEM. While the predicted lower frequency using clamped beam FEM model is more accurate and reasonable.


2019 ◽  
Vol 48 (3) ◽  
pp. 224-248
Author(s):  
Pablo N. Zitelli ◽  
Gabriel N. Curtosi ◽  
Jorge Kuster

ABSTRACT Tire engineers are interested in predicting rolling resistance using tools such as numerical simulation and tests. When a car is driven along, its tires are subjected to repeated deformation, leading to energy dissipation as heat. Each point of a loaded tire is deformed as the tire completes a revolution. Most energy dissipation comes from the cyclic loading of the tire, which causes the rolling resistance in addition to the friction force in the contact patch between the tire and road. Rolling resistance mainly depends on the dissipation of viscoelastic energy of the rubber materials used to manufacture the tires. To obtain a good rolling resistance, the calculation method of the tire finite element model must take into account temperature changes. It is mandatory to calibrate all of the rubber compounds of the tire at different temperatures and strain frequencies. Linear viscoelasticity is used to model the materials properties and is found to be a suitable approach to tackle energy dissipation due to hysteresis for rolling resistance calculation.


2012 ◽  
Vol 568 ◽  
pp. 200-203
Author(s):  
Xiang Nan Wu ◽  
Xiao Liang Zhai ◽  
Ming Min Zhou

There exist evident shear-lag phenomena in large-span composite cable-stayed bridges under the action of axial force, especially in the deck with double main girders. In order to discuss the distribution law of the effective flange width coefficient along the span, caused by axial force, finite element computations of five composite cable-stayed bridges and theoretical analysis have been performed. The transmission angle of axial force caused by the axial compression of stay cables was given, meanwhile the formulas for computation effective slab width coefficient under axial force were suggested.


2017 ◽  
Vol 66 (1) ◽  
pp. 179-187
Author(s):  
Felix Klute ◽  
Torben Jonsky

Abstract One advantage of multi-phase machines is the possibility to use the third harmonic of the rotor flux for additional torque generation. This effect can be maximised for Permanent Magnet Synchronous Machines (PMSM) with a high third harmonic content in the magnet flux. This paper discusses the effects of third harmonic current injection (THCI) on a five-phase PMSM with a conventional magnet shape depending on saturation. The effects of THCI in five-phase machines are shown in a 2D FEM model in Ansys Maxwell verified by measurement results. The results of the FEM model are analytically analysed using the Park model. It is shown in simulation and measurement that the torque improvement by THCI increases significantly with the saturation level, as the amplitude of the third harmonic flux linkage increases with the saturation level but the phase shift of the rotor flux linkage has to be considered. This paper gives a detailed analysis of saturation mechanisms of PMSM, which can be used for optimizing the efficiency in operating points of high saturations, without using special magnet shapes.


Author(s):  
Guilin Li ◽  
Di Shi ◽  
Xiaojiang Zhang

<p>Taking the partial cable-stayed bridge with main span of 248 meters which used on the railway coal corridor from western Inner Mongolia to central China as an example. the adaptability and particularity of partial cable-stayed bridge in the span range are analyzed based on structural static analysis theory. Pylon and girder rigid fixity, pier and beam separation system is applied, H- shaped bridge towers, the double cell concrete box girder and the monofilament epoxy coating prestress strand is used in this bridge. The results indicate that stay-cables contribution to the overall stiffness value of 33%. In order to improve the structure performance of the controlling area such as cross section, bridge tower adopt the high tower type system, depth-span ratio is determined to be 1/4.35, C60 high performance concrete is applied. The main pier bearing adopts double 190000 kN large tonnage steel spherical bearings because of the heavy dead loads and the heavy live loads, using the high-performance materials and Partial sealing technique to ensure the bearing durability, stability and long service life. The structure of the bridge meets the requirements of heavy haul railway according to the analysis.</p>


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