Analysis of the Temperature Field of a PK Section Concrete Girder without Pavement Caused by Solar Radiation

2016 ◽  
Vol 10 (3) ◽  
pp. 34-40
Author(s):  
Wen-chang Xie ◽  
Yu-ping Zhang ◽  
Chuan-xi Li
Keyword(s):  
Temperature Field ◽  
Solar Radiation ◽  
Concrete Girder

A three-dimensional method for the simulation of temperature fields induced by solar radiation

2018 ◽  
Vol 22 (3) ◽  
pp. 567-580 ◽  
Author(s):  
Yihang Yan ◽  
Dingjun Wu ◽  
Qi Li
Keyword(s):  
Temperature Field ◽  
Solar Radiation ◽  
Field Experiments ◽  
Three Dimensional ◽  
Field Analysis ◽  
Temperature Fields ◽  
Structural Deformation ◽  
Solar Radiation Intensity ◽  
Structural Temperature ◽  
Concrete Girder

The determination of temperature fields is usually required for the calculation of structural deformation and stress induced by temperature variation. To guarantee the serviceability and safety of structures by improving calculation accuracy, this study presents a three-dimensional structural temperature field simulation framework that accounts for shadowing effects and changes in solar radiation intensity throughout the day. Field experiments were conducted to update the established model and to verify the accuracy of the numerical algorithm. The proposed method was finally applied in a case study to determine the temperature fields of both a rail and a U-shaped concrete girder. The results show that the temperature field of the concrete girder had obvious nonlinear distribution characteristics. Three-dimensional structural temperature field analysis is especially required for complicated structures with varied sections along the longitudinal axis.

Non-uniform temperature distribution of the main reflector of a large radio telescope under solar radiation

2021 ◽  
Vol 21 (11) ◽  
pp. 293
Author(s):  
Shan-Xiang Wei ◽  
De-Qing Kong ◽  
Qi-Ming Wang
Keyword(s):  
Temperature Field ◽  
Temperature Distribution ◽  
Solar Radiation ◽  
Radio Telescope ◽  
Thermal Imaging ◽  
Uniform Temperature ◽  
Large Radio Telescope ◽  
Uniform Temperature Distribution ◽  
Uniform Temperature Field ◽  
Main Reflector

Abstract The non-uniform temperature distribution of the main reflector of a large radio telescope may cause serious deformation of the main reflector, which will dramatically reduce the aperture efficiency of a radio telescope. To study the non-uniform temperature field of the main reflector of a large radio telescope, numerical calculations including thermal environment factors, the coefficients on convection and radiation, and the shadow boundary of the main reflector are first discussed. In addition, the shadow coverage and the non-uniform temperature field of the main reflector of a 70-m radio telescope under solar radiation are simulated by finite element analysis. The simulation results show that the temperature distribution of the main reflector under solar radiation is very uneven, and the maximum of the root mean square temperature is 12.3°C. To verify the simulation results, an optical camera and a thermal imaging camera are used to measure the shadow coverage and the non-uniform temperature distribution of the main reflector on a clear day. At the same time, some temperature sensors are used to measure the temperature at some points close to the main reflector on the backup structure. It has been verified that the simulation and measurement results of the shadow coverage on the main reflector are in good agreement, and the cosine similarity between the simulation and the measurement is above 90%. Despite the inevitable thermal imaging errors caused by large viewing angles, the simulated temperature field is similar to the measured temperature distribution of the main reflector to a large extent. The temperature trend measured at the test points on the backup structure close to the main reflector without direct solar radiation is consistent with the simulated temperature trend of the corresponding points on the main reflector with the solar radiation. It is credible to calculate the temperature field of the main reflector through the finite element method. This work can provide valuable references for studying the thermal deformation and the surface accuracy of the main reflector of a large radio telescope.

Factors Analysis on the Temperature Field of PC Box-Girder Bridge

2012 ◽  
Vol 178-181 ◽  
pp. 2006-2012
Author(s):  
Yu Dong Nie ◽  
Wei Zhang ◽  
Zong Lin Wang
Keyword(s):  
Thermal Conductivity ◽  
Finite Element ◽  
Temperature Field ◽  
Solar Radiation ◽  
Box Girder ◽  
Finite Element Software ◽  
Plate Length ◽  
Factors Analysis ◽  
Free Air ◽  
Girder Bridge

Based on the Nenjiang Bridge located in the Qi-Gan expressway and using the finite element software ANSYS, we analysis the influences of solar radiation, free air temperature, inside temperature, wind speed, thermal conductivity of concrete, section height, flange plate length and bridge pavement on the temperature field of PC box-girder in this paper. And the solar radiation, thermal conductivity of concrete and bridge pavement is presented as the leading factors for the temperature field of PC box-girder.

Numerical Simulation on Temperature Field of CFST Member under Solar Radiation

2011 ◽  
Vol 354-355 ◽  
pp. 1241-1244
Author(s):  
Yan He ◽  
Man Ding ◽  
Qian Zhang
Keyword(s):  
Numerical Simulation ◽  
Temperature Field ◽  
Temperature Distribution ◽  
Solar Radiation ◽  
Cross Section ◽  
Temperature Difference ◽  
Steel Tube ◽  
Concrete Filled Steel Tube ◽  
Nonlinear Temperature ◽  
The Cross

In this paper the temperature field of Concrete Filled Steel Tube (CFST) member under solar radiation is simulated. The results show that temperature distribution caused by solar radiation is nonlinear over the cross-section of CFST member, and it is significantly varied with time and sections, the largest nonlinear temperature difference is over 26.3°C.

Numerical Assessment on Time-Varying Temperature Field of Bridge Tower under Solar Radiation

2012 ◽  
Vol 204-208 ◽  
pp. 2236-2239 ◽  
Author(s):  
Bo Chen ◽  
Wei Hua Guo ◽  
Chun Fang Song ◽  
Kai Kai Lu
Keyword(s):  
Heat Transfer ◽  
Finite Element ◽  
Temperature Field ◽  
Temperature Distribution ◽  
Solar Radiation ◽  
Ambient Air ◽  
Heat Transfer Analysis ◽  
Time Varying ◽  
Long Span ◽  
Bridge Tower

Bridge tower, time-varying temperature field, heat transfer analysis, finite element model. Abstract. Long span suspension bridges are subjected to daily, seasonal and yearly environmental thermal effects induced by solar radiation and ambient air temperature. This paper aims to investigate the temperature distribution of a tower of a long span suspension bridge. Two-dimensional heat transfer models are utilized to determine the time-dependent temperature distribution of the bridge tower of the bridge. The solar radiation model is utilized to examine the time-varying temperature distribution. Finite element models are constructed for the bridge tower to compute the temperature distribution. The numerical models can successfully predict the structural temperature field at different time. The methodology employed in the paper can be applied to other long-span bridges as well.

Research of Temperature Field of Long Span Concrete Box Girder Bridge Caused by Solar Radiation

2012 ◽  
Vol 256-259 ◽  
pp. 1635-1639
Author(s):  
Cun Ren Jiang ◽  
Jian Min Ren ◽  
Zhuo Ling Wang
Keyword(s):  
Temperature Field ◽  
Temperature Gradient ◽  
Solar Radiation ◽  
Structure Design ◽  
Box Girder ◽  
Qinghai Province ◽  
Long Span ◽  
Concrete Box Girder ◽  
Girder Bridge ◽  
Bottom Slab

When stimulate temperature field of concrete box girder caused by solar radiation with ANSYS, it’s feasible to turn boundary conditions to third boundary condition. Taking Ping'an Huangshui River Super-large Bridge in Qinghai Province for example, the research analyzes box girder temperature field distribution and deduces realistic temperature gradient mode by comparing calculations with measurements. Calculations show that bottom slab of box girder also has quite big temperature gradient which should be taken seriously in bridge structure design.

Numerical Simulation of Sea Surface Transient Temperature Field

2012 ◽  
Vol 482-484 ◽  
pp. 497-500
Author(s):  
Shi Cheng Zhang ◽  
Zhen Yang ◽  
Li Yang
Keyword(s):  
Temperature Field ◽  
Heat Exchange ◽  
Solar Radiation ◽  
Infrared Imaging ◽  
Surface Wind ◽  
Sea Surface ◽  
Transient Temperature ◽  
Temperature Model ◽  
Transient Temperature Field ◽  
Imaging Simulation

Sea surface temperature (SST) is a prerequisite for sea surface infrared imaging simulation. A temperature model suitable for seawater heat exchange is proposed based on the heat balance of air-sea interface and equations of fluid heat exchange. The model considers the air-sea heat transfer characteristics and influences of penetrating solar radiation in seawater. Effects of the solar radiation, sea surface wind speed and air temperature on SST are analyzed. Temperature model is also used to simulate the SST diurnal variation and compared with the measured values to verify the validity of the model. The results show that the model is useful for solution of sea surface transient temperature field and provides the basis for infrared imaging simulation of sea surface.

A novel thermo-flexible coupled dynamics analysis method of planar deployable structures in the deploying process

2019 ◽  
Vol 233 (17) ◽  
pp. 6089-6098 ◽  
Author(s):  
Qi'an Peng ◽  
Sanmin Wang ◽  
Bo Li ◽  
Changjian Zhi ◽  
Jianfeng Li
Keyword(s):  
Temperature Field ◽  
Solar Radiation ◽  
Thermal Loading ◽  
Incidence Angle ◽  
Linear Interpolation ◽  
Dynamics Analysis ◽  
Analysis Method ◽  
Deployable Structures ◽  
Thermally Induced ◽  
Interpolation Functions

The temperature-induced vibration of deployable structures caused by the temperature gradient due to heat flux from the solar radiation is a major factor that results in a significant effect on synchronism of the deploying motion. In this paper, a coupled thermo-flexible dynamics analysis method of deployable structures is presented. In this method, the temperature field of thin-walled rectangular tube element subjected to the solar radiation is established by the linear interpolation functions and the proposed high-order polynomials. The two methods, respectively, are used to approximate the axial and circumferential temperature distributions. Then, the dynamics equations of the tube element are derived by the extended absolute node coordinate formulation with the temperature field inset and verified by comparing with ANSYS. Next, the coupled thermo-flexible dynamics equations of the deploying mechanisms are assembled by the virtue of rods and constraint conditions. Finally, the deployable structure with three scissor-like units is analyzed as a numerical example. The simulation results show that the thermal loading has a significant impact on the displacement, straightness, and driving force due to thermally induced bends and vibrations and the incidence angle of the solar radiation is a key parameter to determine the different aspects of the temperature influence.

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