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.

Temperature Field Analysis and Cooling Structure Design of Ironless Permanent Magnet Synchronous Linear Motor

2021 ◽  
Vol 14 ◽  
Author(s):  
Xiaoting Lu ◽  
Yang Li ◽  
Zailiang Chen
Keyword(s):  
Temperature Field ◽  
Permanent Magnet ◽  
Heat Loss ◽  
Linear Motor ◽  
Structure Design ◽  
Servo Control ◽  
Field Analysis ◽  
Temperature Fields ◽  
Water Cooling ◽  
Linear Motors

Objective: Ironless, permanent magnet, synchronous linear (IPMSL) motors are applied widely in precision servo control for the nonexistence of cogging forces and comparatively small fluctuations in thrust and speed. Method: The air and water cooling structures are designed by assuming the heat loss in the motor operations is the source for the distribution of the temperature field in the analysis under natural cooling. Conclusion: The temperature fields of the linear motor under the two cooling modes are compared and analyzed, which helps monitor the temperature of linear motors during development and operations.

scholarly journals Analysis of temperature-induced deformation and stress distribution of long-span concrete truss combination arch bridge based on bridge health monitoring data and finite element simulation

2020 ◽  
Vol 16 (10) ◽  
pp. 155014772094520
Author(s):  
Yanwei Niu ◽  
Yong’e Wang ◽  
Yingying Tang
Keyword(s):  
Finite Element ◽  
Temperature Distribution ◽  
Stress Distribution ◽  
Health Monitoring ◽  
Three Dimensional ◽  
Monitoring Data ◽  
Temperature Fields ◽  
Structural Deformation ◽  
Arch Bridge ◽  
Bridge Health Monitoring

Through decades of operation, deformation fluctuation becomes a central problem affecting the normal operating of concrete truss combination arch bridge. In order to clarify the mechanism of temperature-induced deformation and its impact on structural stress distribution, this article reports on the temperature distribution and its effect on the deformation of concrete truss combination arch bridge based on bridge health monitoring on a proto bridge with 138 m main span. The temperature distribution and deformation characteristics of the bridge structure in deep valley area are studied. Both of the daily and yearly temperature variation and structural deformation are studied based on bridge health monitoring. Using the outcome of monitoring data, three-dimensional solid finite element models are established to analyze the mechanism of temperature-induced deformation of the whole bridge under different temperature fields. The influence of temperature-induced effect is discussed on local damage based on the damage observation of the background bridge. The outcome of comparisons with field observation validates the analysis results. The relevant monitoring and simulation result can be referenced for the design and evaluation of similar bridges.

scholarly journals Analysis of spatial thermal field in a magnetic bearing

Open Physics ◽  
2018 ◽  
Vol 16 (1) ◽  
pp. 52-56
Author(s):  
Dawid Wajnert ◽  
Bronisław Tomczuk
Keyword(s):  
Temperature Field ◽  
Mathematical Models ◽  
Computer Simulations ◽  
Thermal Field ◽  
Three Dimensional ◽  
Magnetic Bearing ◽  
Field Analysis ◽  
Two Dimensional ◽  
Temperature Distributions ◽  
Dimensional Simulation

AbstractThis paper presents two mathematical models for temperature field analysis in a new hybrid magnetic bearing. Temperature distributions have been calculated using a three dimensional simulation and a two dimensional one. A physical model for temperature testing in the magnetic bearing has been developed. Some results obtained from computer simulations were compared with measurements.

scholarly journals Impact of Tunnel Temperature Variations on Surrounding Rocks in Cold Regions

2019 ◽  
Author(s):  
Qingyang Yu ◽  
Chao Zhang ◽  
Zhenxue Dai ◽  
Chao Du ◽  
Mohamad Reza Soltanian ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Temperature Field ◽  
Temperature Distribution ◽  
Three Dimensional ◽  
Temperature Fields ◽  
Insulation Layer ◽  
Cold Regions ◽  
Ambient Temperatures ◽  
Temperature Conditions ◽  
Layer Control

Temperature is an important factor in designing and maintaining tunnels, especially in cold regions. We present three-dimensional numerical simulations of tunnel temperature fields at different temperature conditions. We study the tunnel temperature field in two different conditions with relatively low and high ambient temperatures representing winter and summer of northeast China. We specifically study how these temperature conditions affect tunnel temperature and its migration to surrounding rocks. We show how placing an insulation layer could affect the temperature distribution within and around tunnels. Our results show that the temperature field without using an insulation layer is closer to the air temperature in the tunnel, and that the insulation layer has shielding effects and could plays an important role in preventing temperature migration to surrounding rocks. We further analyzed how thermal conductivity and thickness of insulation layer control the temperature distribution. The thermal conductivity and thickness of insulation layer only affect the temperature of the surrounding rocks which are located at distances below ~20 m from the lining.

Analysis of Plastic Strain Localization on the Basis of Strain and Temperature Fields / Analiza Lokalizacji Odkształcenia Plastycznego Na Podstawie Pola Odkształceń I Pola Temperatury

2012 ◽  
Vol 57 (4) ◽  
pp. 1111-1116 ◽  
Author(s):  
M. Maj ◽  
W. Oliferuk
Keyword(s):  
Temperature Field ◽  
Temperature Distribution ◽  
Plastic Strain ◽  
Strain Localization ◽  
Field Analysis ◽  
Temperature Fields ◽  
Uniform Temperature ◽  
Experimental Conditions ◽  
Plastic Strain Localization ◽  
Uniform Temperature Distribution

In the present paper the onset of plastic strain localization was determined using two independent methods based on strain and temperature field analysis. The strain field was obtained from markers displacement recorded using visible light camera. In the same time, on the other side of the specimen, the temperature field was determined by means of infrared camera. The objective of this work was to specify the conditions when the non-uniform temperature distribution can be properly used as the indicator of plastic strain localization. In order to attain the objective an analysis of strain and temperature fields for different deformation rates were performed. It has been shown, that for given experimental conditions, the displacement rate 2000 mm/min is a threshold, above which the non-uniform temperature distribution can be used as the indicator of plastic strain localization.

Effects of solar radiation on thermal sensation and physical fatigue of the human body under heavy-load exercise

2020 ◽  
pp. 1420326X2097473
Author(s):  
Yongqiang Xiao ◽  
Yaping Gao ◽  
Yi Wang ◽  
Xiaojing Meng
Keyword(s):  
Blood Pressure ◽  
Solar Radiation ◽  
Ambient Temperature ◽  
Human Body ◽  
Field Experiments ◽  
Physiological Stress ◽  
Thermal Sensation ◽  
Heavy Load ◽  
Solar Radiation Intensity ◽  
Significant Difference

Solar radiation intensity affects both subjective reactions and physiological functions, especially for people who exercise heavily. Field experiments including a questionnaire survey at various ambient temperatures were performed; outdoor activities under shading (irradiance I =  50 ± 20 W/m2) and non-shading ( I =  700 ± 50 W/m2) conditions during summer in Xi'an were recorded. The results of questionnaires indicated that when the human body reached an extremely hot state, the corresponding environmental temperature was 3.7 °C lower under the non-shading condition, and the range of actual acceptable temperatures was narrower. In terms of thermal sensation, there was a significant difference for people who exercise heavily and those who do not. The results also showed that the curve of fatigue sensation exhibited an inverse Gaussian distribution. Namely, fatigue was promoted under both colder and hotter conditions. Moreover, under non-shading condition, the lowest fatigue incidence was higher, and the corresponding ambient temperature was lower. Changes in objective physiological responses indicated that the solar radiation might cause heat stress. Therefore, when the ambient temperature was higher than 32 °C, physiological stress was higher. Under the same exercise load, the blood pressure was higher under the non-shading condition and systolic blood pressure increased with ambient temperature.

Three-Dimensional Analytical Temperature Field Around the Welding Cavity Produced by a Moving Distributed High-Intensity Beam

1993 ◽  
Vol 115 (4) ◽  
pp. 848-856 ◽  
Author(s):  
P. S. Wei ◽  
M. D. Shian
Keyword(s):  
Temperature Field ◽  
Power Density ◽  
High Power ◽  
Three Dimensional ◽  
Second Law Of Thermodynamics ◽  
Temperature Fields ◽  
Momentum Balance ◽  
High Power Density ◽  
Depth Of Penetration ◽  
Confluent Hypergeometric Functions

An analytical solution for the three-dimensional temperature field in the liquid and heat-affected zones around a welding cavity produced by a moving distributed low- or high-power-density-beam is provided. The incident energy rate distribution is assumed to be Gaussian and the cavity is idealized by a paraboloid of revolution in workpieces of infinite, semi-infinite, or finite thicknesses. The present study finds that temperature fields can be described by the Laguerre and confluent hypergeometric functions. By satisfying a momentum balance at the cavity base and utilizing a consequence of the second law of thermodynamics, the depth of penetration is uniquely determined. The results show that the predicted depths and temperatures of the cavity agree with available experimental data. Some crucial factors affecting the transition from low- to high-power-density-beam welding are presented.

Analysis of Transient Heat Conduction in Complex Shaped Composite Materials

1988 ◽  
Vol 110 (2) ◽  
pp. 110-112 ◽  
Author(s):  
Seiichi Nomura ◽  
A. Haji-Sheikh
Keyword(s):  
Temperature Field ◽  
Heat Conduction ◽  
Composite Materials ◽  
Analytical Procedure ◽  
Three Dimensional ◽  
Transient Heat Conduction ◽  
Temperature Fields ◽  
Finite Region ◽  
Symbolic Algebra ◽  
The Galerkin Method

This paper addresses a generalized analytical procedure for transient heat conduction in composite materials of two- and three-dimensional finite region. The Galerkin method is employed to obtain temperature field in closed form with the utilization of symbolic algebra software such as REDUCE or MACSYMA. It is found from illustrative examples that the proposed method yields accurate and effective predictions of temperature fields for which purely numerical methods such as finite element or finite difference are not suitable.

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