Test and simulation analysis on early temperature field of the main girder for a concrete cable-stayed bridge

Author(s):  
Qi Li ◽  
Qibiao Chen ◽  
Peng Wang ◽  
Jianxin Yuan
2014 ◽  
Vol 1065-1069 ◽  
pp. 992-996
Author(s):  
Can Huang ◽  
Yi Zhi Bu ◽  
Qing Hua Zhang

Based on the energy method and beam-element theory, the nonlinear strain are considered, non-stress length and non-stress curvature of element of geometry control method are introducted in the integration process of stain energy. The static equilibrium equation of the geometry control method is established. Take the impacts of structural geometric profile induced by temporary loads and temperature field during the construction procedure are investigated, the correctness of the geometry control method is verified by the numerical simulation analysis.


2014 ◽  
Vol 2014 ◽  
pp. 1-16
Author(s):  
Gao-Xin Wang ◽  
You-Liang Ding

Based on the health monitoring system installed on the main span of Sutong Cable-Stayed Bridge, GPS displacement and wind field are real-time monitored and analyzed. According to analytical results, apparent nonlinear correlation with certain discreteness exists between lateral static girder displacement and lateral static wind velocity; thus time series of lateral static girder displacement are decomposed into nonlinear correlation term and discreteness term, nonlinear correlation term of which is mathematically modeled by third-order Fourier series with intervention of lateral static wind velocity and discreteness term of which is mathematically modeled by the combined models of ARMA(7,4)and EGARCH(2,1). Additionally, stable power spectrum density exists in time series of lateral dynamic girder displacement, which can be well described by the fourth-order Gaussian series; thus time series of lateral dynamic girder displacement are mathematically modeled by harmonic superposition function. By comparison and verification between simulative and monitoring lateral girder displacements from September 1 to September 3, the presented mathematical models are effective to simulate time series of lateral girder displacement from main girder of Sutong Cable-Stayed Bridge.


Author(s):  
Shaolin Chen ◽  
Hong Zhang ◽  
Liaoping Hu ◽  
Guangqing He ◽  
Fen Lei ◽  
...  

The fatigue life of turbine housing is an important index to measure the reliability of a radial turbocharger. The increase in turbine inlet temperatures in the last few years has resulted in a decrease in the fatigue life of turbine housing. A simulation method and experimental verification are required to predict the life of a turbine housing in the early design and development process precisely. The temperature field distribution of the turbine housing is calculated using the steady-state bidirectional coupled conjugate heat transfer method. Next, the temperature field results are considered as the boundary for calculating the turbine housing temperature and thermomechanical strain, and then, the thermomechanical strain of the turbine housing is determined. Infrared and digital image correlations are used to measure the turbine housing surface temperature and total thermomechanical strain. Compared to the numerical solution, the maximum temperature RMS (Root Mean Square) error of the monitoring point in the monitoring area is only 3.5%; the maximum strain RMS error reached 11%. Experimental results of temperature field test and strain measurement test show that the testing temperature and total strain results are approximately equal to the solution of the numerical simulation. Based on the comparison between the numerical calculation and experimental results, the numerical simulation and test results were found to be in good agreement. The experimental and simulation results of this method can be used as the temperature and strain (stress) boundaries for subsequent thermomechanical fatigue (TMF) simulation analysis of the turbine housing.


Symmetry ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 2293
Author(s):  
Zixiang Yue ◽  
Youliang Ding ◽  
Hanwei Zhao ◽  
Zhiwen Wang

A cable-stayed bridge is a typical symmetrical structure, and symmetry affects the deformation characteristics of such bridges. The main girder of a cable-stayed bridge will produce obvious deflection under the inducement of temperature. The regression model of temperature-induced deflection is hoped to provide a comparison value for bridge evaluation. Based on the temperature and deflection data obtained by the health monitoring system of a bridge, establishing the correlation model between temperature and temperature-induced deflection is meaningful. It is difficult to complete a high-quality model only by the girder temperature. The temperature features based on prior knowledge from the mechanical mechanism are used as the input information in this paper. At the same time, to strengthen the nonlinear ability of the model, this paper selects an independent recurrent neural network (IndRNN) for modeling. The deep learning neural network is compared with machine learning neural networks to prove the advancement of deep learning. When only the average temperature of the main girder is input, the calculation accuracy is not high regardless of whether the deep learning network or the machine learning network is used. When the temperature information extracted by the prior knowledge is input, the average error of IndRNN model is only 2.53%, less than those of BPNN model and traditional RNN. Combining knowledge with deep learning is undoubtedly the best modeling scheme. The deep learning model can provide a comparison value of bridge deformation for bridge management.


Author(s):  
Tsuguo Oishi ◽  
Yasuo Inokuma

The Odawara Port Bridge is located at the mouth of Odawara Port. Selecting a bridge type that symbolized the entire project and blended well with the surrounding area was critical. To achieve this, an extra-dosed prestressed concrete box girder with a main span of 122 m was selected. Construction of this bridge type is the first in the world. Special characteristics of this bridge type are a lower tower height than that of a cable-stayed bridge, the use of a saddle at the top of the towers, and the incorporation of epoxy-coated strands for diagonal cables. The design of the various sections of the bridge was achieved by integrating the characteristic shape of the towers with cable profiles while establishing horizontal continuity with the main girder. As a result of the integration process, the following design objectives were adopted: (a) constant main girder depth; (b) inverted trapezoidal main girder cross section; (c) towers without a connecting beam at the top; (d) a fan-shaped saddle; (e) compact cable vibration dampers; (f) graded metallic coloring of cables; (g) integrated steel railing and road surface lighting; (h) nighttime bridge lighting, and (i) encased drainage pipes.


2017 ◽  
Vol 872 ◽  
pp. 251-255
Author(s):  
Sen Wang ◽  
Yang Yang Zhao ◽  
Hong Kui Yan ◽  
Dong Ling Liu ◽  
Dong Sheng Zhao ◽  
...  

Taking efficient pumping-unit linear motor as the research object in this paper, SOLIDWORK has been used to establish 3D model and analyze multi-physics of the efficient pumping-unit linear motor, including vibration mode, stress analysis and the analysis of temperature field. Through the simulation analysis, getting efficient pumping unit linear motor of the top five order vibration frequency, pressure distribution and temperature distribution, theoretical references are provided for the analysis of the efficient pumping-unit linear motor. The innovation of the article is in coupling analysis of multi-physics.


2014 ◽  
Vol 614 ◽  
pp. 124-127
Author(s):  
Meng Kai Lin ◽  
Hai Lian Li

Taking the concrete pouring for a passenger station’s pile cap as the research background, the paper establishes a model of pile cap’s hydration heat, by using the finite element software MIDAS. The paper also studies the main parameters and the temperature field theory which affect the hydration heat. It indicates that the pipe cooling method can significantly reduce the temperature difference between the inside and the outside when pouring massive concretes, and it is an effective way to prevent the generation of cracks.


2012 ◽  
Vol 174-177 ◽  
pp. 3027-3030
Author(s):  
Wei Wei ◽  
Ming Zhong Wang ◽  
Jun Pan

In order to avoid the heat transfixion among users in the concentration area of the water source heat pump, a suitable layout of pumps for drawing and recharging wells is required. Finite element method is adopted to establish the numerical model of groundwater temperature to predict the change trend of water temperature. The results of the simulation indicate that the groundwater temperature change from 6.3 to 14.2 °C in winter, and from 11.5 to 21.2 °C in summer. These results meet the requirements of the drawing and recharging water in the water source heat pump engineering and are able to avoid the heat transfixion among users. The effect of drawing and recharging water in the water source heat pump engineering to the changes of the groundwater’s temperature field can be analyzed quantitatively through establishing the proper numerical simulation which provides a reference to scientifically design the layout of pumps for drawing and recharging water.


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