Three-Dimensional Numerical Computation for Temperature Field and Insulator of Cold Regions Tunnel

2012 ◽  
Vol 503-504 ◽  
pp. 132-135
Author(s):  
Jin Xing Lai ◽  
Chi Liu ◽  
Guang Long Zhang
Keyword(s):  
Temperature Field ◽  
Three Dimensional ◽  
Longitudinal Direction ◽  
Transient Temperature ◽  
Burial Depth ◽  
Cold Region ◽  
Insulating Layer ◽  
Thermal Insulating ◽  
Longitudinal Length ◽  
Three Dimensional Finite Element

With heat conduction differential equation of the transient temperature field, Galerkin method is adopted to deduce the three-dimensional finite element formula; based on the test result of temperature field, the actual temperature of the environment inside the tunnel shall be exerted on surface of the second lining concrete as load, thus establish the three dimensional computation model of the temperature field of tunnel in cold region. Next, on basis of the model, numerical analysis on cross section of burial depth and longitudinal direction of tunnel in cold region with and without thermal insulating layer, so as to provide theoretical basis for thickness and longitudinal length of thermal insulating layer laid in tunnel of cold region.

Analysis for Temperature Field and Stress of Concrete Volute Structure

2011 ◽  
Vol 90-93 ◽  
pp. 2418-2422
Author(s):  
Xiao Bing Sun ◽  
Xue Ping Peng
Keyword(s):  
Temperature Field ◽  
Optimization Design ◽  
Thermal Stresses ◽  
Heat Waves ◽  
Water Pressure ◽  
Three Dimensional ◽  
Transient Temperature ◽  
Transient Temperature Field ◽  
Dimensional Finite Element ◽  
Three Dimensional Finite Element

Study on temperature field and thermal stresses of a large volume concrete volute structure is important to prevent the concrete structure cracking caused by excessively tensile strains that result from the cold or heat waves and the internal water pressure. By use of the three dimensional finite element method, the displacements and stresses of a concrete volute under the external loads are calculated. The transient temperature field and the thermal stress distribution of the concrete volute caused by the cold or heat waves are obtained, and the thermo-structural coupling stress field analyses for some cases are completed detailly. The calculating results are the basis for the optimization design of the concrete volute structure.

Numerical Simulation of Three-Dimensional Molten Pool Temperature Field and Flow Field for Laser Melt Injection Based on Fluent

2012 ◽  
Vol 538-541 ◽  
pp. 1837-1842 ◽  
Author(s):  
Long Zhi Zhao ◽  
Zi Wang ◽  
Xin Yan Jiang ◽  
Jian Zhang ◽  
Ming Juan Zhao
Keyword(s):  
Temperature Field ◽  
Liquid Metal ◽  
Molten Pool ◽  
Metal Flow ◽  
Three Dimensional ◽  
Transient Temperature ◽  
Transient Temperature Field ◽  
Liquid Metal Flow ◽  
Fluent Software ◽  
Thermo Physical Properties

According to the characteristics of laser melt injection, a numerical model for a simplified 3D transient temperature field in molten pool was established using FLUENT software in this paper. In the model, many factors were considered such as liquid metal turbulence, latent heat of phase transformation and material thermo physical properties depending on temperature. The results show that the model can be developed well by FLUENT software. And the results also show that the driving force of the liquid metal flow mechanism.

Modelling of the laser surface nitriding of Ti-6Al-4V alloy—analysis of heat transfer and residual stresses

2001 ◽  
Vol 215 (3) ◽  
pp. 315-340 ◽  
Author(s):  
M Labudovic ◽  
R Kovacevic
Keyword(s):  
Residual Stresses ◽  
High Speed ◽  
Parametric Design ◽  
Three Dimensional ◽  
Laser Surface ◽  
Transient Temperature ◽  
X Ray Diffraction ◽  
Dimensional Finite Element ◽  
On Line ◽  
Three Dimensional Finite Element

A three-dimensional finite element modelling of the laser surface nitriding of Ti-6A1-4V alloy is presented. Design capabilities of ANSYS parametric design language (APDL) were employed for this purpose. The model calculates transient temperature profiles, the dimensions of fusion zone and residual stresses in the laser surface nitrided Ti-6A1-4V alloy. Model simulations are compared with experimental results, acquired on-line using an ultra-high-speed shutter camera which is able to acquire well-contrasted images of the molten pool, and off-line using metallographical and X-ray diffraction analyses which show very good agreement. The results are further discussed to provide directions for reducing the residual stresses, as well as for feedback and process control.

Three-dimensional transient temperature field model for laser annealing

2005 ◽  
Vol 97 (3) ◽  
pp. 033520 ◽  
Author(s):  
Jean-Yves Degorce ◽  
Jean-Numa Gillet ◽  
François Magny ◽  
Michel Meunier
Keyword(s):  
Temperature Field ◽  
Laser Annealing ◽  
Field Model ◽  
Three Dimensional ◽  
Transient Temperature ◽  
Transient Temperature Field ◽  
Temperature Field Model

Modeling of the Temperature Field during Electron Beam Welding of Aluminum Alloy by a Pre-Defined Keyhole

2007 ◽  
Vol 353-358 ◽  
pp. 2011-2014
Author(s):  
Yan Hong Tian ◽  
Chun Qing Wang ◽  
Dan Yang Zhu
Keyword(s):  
Temperature Field ◽  
Electron Beam ◽  
Heat Source ◽  
Electron Beam Welding ◽  
Three Dimensional ◽  
Source Model ◽  
Transient Temperature ◽  
Al Alloy ◽  
Welding Pool ◽  
Welding Line

The transient temperature field of Al alloy during electron beam welding (EBW) process was simulated using a three-dimensional finite element method. Different from the most previous models which were based on the assumption that the welding pool was solid and neglected the existence of keyhole by meshing the solid as a whole, a dynamic three-dimensional keyhole was applied in this model. The profile of the keyhole was ellipse and its size was determined before simulation based on the results of experiments. Following the heat source, the pre-defined keyhole moved along the welding line. A three-dimensional complex heat source model, including a modified Gaussian distribution source and a uniform source, was used in this study. The result shows that the shape of the keyhole had a direct effect on the temperature distribution and contribution to the special shape of the welding pool in EBW.

Analysis of Nonlinear Heat Transfer and Residual Stresses during Multi-Pass Welding of Penetration Assembly

2009 ◽  
Vol 417-418 ◽  
pp. 149-152 ◽  
Author(s):  
Hong Li ◽  
Li Li
Keyword(s):  
Residual Stresses ◽  
Three Dimensional ◽  
Transient Temperature ◽  
Butt Welding ◽  
Time Dynamic ◽  
Transient Temperature Field ◽  
Dimensional Finite Element ◽  
Nonlinear Transient ◽  
Girth Welds ◽  
Three Dimensional Finite Element

Welding residual plastic strains and stresses cause errors during the assembly and reduce the strength of the structure. Based on an elastic-plastic-model, a three-dimensional finite element numerical simulation of multi-pass butt welding of a representative penetration assembly is carried out in this paper. The nonlinear transient temperature field and the real-time dynamic stresses field during multi-pass butt welding with girth welds are obtained. In the end, the residual stresses of the complicated stainless steel penetration structure are calculated by FEM software ANSYS.

scholarly journals Research on the Temperature Field and Frost Heaving Law of Massive Freezing Engineering in Coastal Strata

2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Chaochao Zhang ◽  
Dongwei Li ◽  
Junhao Chen ◽  
Guanren Chen ◽  
Chang Yuan ◽  
...  
Keyword(s):  
Temperature Field ◽  
Three Dimensional ◽  
Element Model ◽  
Freezing Temperature ◽  
Frozen Soil ◽  
Physical Parameters ◽  
Frost Heaving ◽  
Soil Frost ◽  
Dimensional Finite Element ◽  
Three Dimensional Finite Element

In this study, based on the background of massive freezing engineering in coastal strata, the thermal physical parameters and some freezing laws of soil were obtained through soil thermal physical tests and frozen soil frost heaving tests. When the freezing temperatures were −5°C, −10°C, −15°C, and −20°C, the frost heaving rates of the soil were 0.53%, 0.95%, 1.28%, and 1.41%, and the frost heaving forces of the soil were 0.37 MPa, 0.46 MPa, 0.59 MPa, and 0.74 MPa, respectively. In the range of test conditions, the frost heaving rate and the frost heaving force of the soil increased with the decrease of the freezing temperature, and the relationship was roughly linear with the temperature. The entire cooling process could be roughly divided into three stages: active freezing stage, attenuation cooling stage, and stability stage. The range of the frozen soil expansion did not increase linearly with the decrease of the freezing temperature, and there was a limit radius for the frozen soil expansion. A three-dimensional finite element model was established to simulate the temperature field and frost heaving of the soil under the on-site working conditions. The entire frost heaving process could be roughly divided into two stages. The calculated temperature values and the frost heaving force values were compared with the on-site measured values, and the results verified that the numerical calculation could accurately reflect the temperature field and frost heaving law of the formation.

scholarly journals Research on Model Slice and Forming Method of Thin-walled Parts

2021 ◽  
Vol 233 ◽  
pp. 04046
Author(s):  
Changhao Zhang ◽  
Hu Li ◽  
Jianyu Yang ◽  
Huawei Lu ◽  
Peng Su
Keyword(s):  
Numerical Simulation ◽  
Temperature Field ◽  
Structural Characteristics ◽  
Three Dimensional ◽  
Simulation Method ◽  
Processing Parameters ◽  
Transient Temperature ◽  
Transient Temperature Field ◽  
Thin Walled ◽  
Experimental Processing

According to the structural characteristics of thin-walled parts, a model slicing method is proposed, and its mathematical process is established. The three-dimensional transient temperature field in the process of synchronous powder feeding laser cladding is studied and verified by numerical simulation method, and the thin-walled parts formed by later experimental processing are processed by the results of numerical simulation. Using the simulation results of temperature field as the basis for optimizing the processing parameters, the forming path of thin-walled parts is programmed and optimized, and the experimental verification shows the reliability of this method.

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