scholarly journals Study on Temperature Control of Gravity Anchorage without Cooling Water

2022 ◽  
Vol 2148 (1) ◽  
pp. 012050
Author(s):  
Hanzheng Xu ◽  
Yazhou Yin ◽  
Kaihan Xu ◽  
Chongjin Li
Keyword(s):  
Cooling Water ◽  
Suspension Bridge ◽  
Simulation Software ◽  
Heating Process ◽  
Mass Concrete ◽  
Convection Coefficient ◽  
Air Convection ◽  
Fea Simulation ◽  
Anchor Block ◽  
Surface Convection

Abstract This paper uses Midas Fea simulation software to analyze the hydration heat of a suspension bridge anchorage mass concrete construction without cooling water. According to specific boundary conditions and convection coefficients, the concrete heating process and cooling process are simulated. Analyze the influence of surface air convection coefficient on the surface tensile stress of the cast layer, and the influence of the pouring interval on the interlayer stress of the anchor block, and the temperature difference between the inside and outside of the concrete when the anchor block is layered. It is found that reducing the surface convection coefficient of the pouring layer can effectively improve the stress condition, and the pouring interval has little effect on the stress.

Heating Path Generation and Simulation for Ship Plate Steel

2011 ◽  
Vol 421 ◽  
pp. 250-253
Author(s):  
Hu Zhu ◽  
Xiao Guang Yang
Keyword(s):  
Steel Plate ◽  
Simulation System ◽  
Simulation Software ◽  
Heating Process ◽  
Path Generation ◽  
Plate Steel ◽  
Heating Equipment ◽  
Line Heating ◽  
Steel Base

To lay the foundation of the automation for line heating forming, a method for heating path generation and simulation for ship plate steel base on STL mode was proposed in this paper. The line heating path was generated by slicing the STL model of the steel plate using a series of planes, and the models of the heating equipment of ship plate steel were build, and the heating process of ship plate steel can be simulated by inputting the models of the heating equipment into the simulation system that was built by using VC++ and OpenGL. The case study shows that the method can primely solve the inconvenient of manual heating and the whole heating process can be observed by the simulation so that the heating process can be made a reasonable monitoring, and the heating path generation and simulation software are runs stably and reliably.

Study on Forced Convection Boundary Condition for Subcooled Water in the Simulation of Line-Heating Process

2006 ◽  
Vol 22 (01) ◽  
pp. 41-47
Author(s):  
Wang Ji ◽  
Liu Yujun ◽  
Ji Zhuoshang ◽  
Deng Yanping ◽  
Zhang Jun
Keyword(s):  
Boundary Condition ◽  
Forced Convection ◽  
Great Influence ◽  
Nucleate Boiling ◽  
Heating Process ◽  
Convection Coefficient ◽  
Line Heating ◽  
Subcooled Water ◽  
Convection Boundary Condition ◽  
Convection Boundary

In the simulation of line-heating process, the convection boundary condition, especially the subcooled water forced convection, has great influence on the result. The calculation of the convection coefficient is a difficult problem in the simulation. This paper uses the theory of forced convection boiling to study subcooled water forced convection during the line-heating process. By solving the wall temperatures of originating nucleate boiling and critical heat flux for subcooled water and comparing the plate temperature with these two wall temperatures, the status of water can be determined, and then the corresponding convection coefficient is calculated. The simulation results show that the precision of the forced convection boiling boundary condition presented in this paper is much better than that of a boundary condition based on the pool boiling curve.

Finite Element Analysis on Key Components of Horizontal Refuse Compactor

2013 ◽  
Vol 584 ◽  
pp. 24-28
Author(s):  
He Nan Chen ◽  
Shou Cheng Wang ◽  
Yuan Wang
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Sharp Increase ◽  
Simulation Software ◽  
Element Analysis ◽  
Operation Efficiency ◽  
Fea Simulation ◽  
Environmental Amelioration

This subject is proposed via authentic market investigation, based on the sharp increase of household garbage in urban cities and urgent demand for environmental amelioration in recent years. Taking horizontal refuse compactor as an example, this paper optimizes the configuration of key components of refuse compactors, by employing Finite Element Analysis (FEA) method, aiming to select the most appropriate components to equip compactors, whose operation efficiency can be markedly enhanced. The statics analysis for each key component is individually conducted by applying ABAQUS, the FEA simulation software, to test the reliability of this new structure.

scholarly journals Stress and damage in concrete induced by pipe cooling at mesoscopic scale

2017 ◽  
Vol 9 (2) ◽  
pp. 168781401769050 ◽  
Author(s):  
Yongrong Qiu ◽  
Guoxin Zhang
Keyword(s):  
Temperature Difference ◽  
Homogeneous Model ◽  
Cooling Water ◽  
Second Phase ◽  
Mass Concrete ◽  
Cooling Mode ◽  
Heterogeneous Model ◽  
Research Results ◽  
Advantages And Disadvantages ◽  
Induced Stress

Pipe cooling is one of the most important measures of mass concrete temperature control, but pipe cooling has its advantages and disadvantages. Inappropriate pipe-cooling water temperature may result in excessive stress and crack. Considering the fact that concrete is a type of three-phase composite material and the sizes of cooling pipe and aggregate are basically on the same scale, the mesoscopic heterogeneity of concrete may have a great effect on the stress field surrounding the pipe. This article computes the pipe cooling–induced stress and damage and analyzes the differences between the homogeneous model and heterogeneous model based on mesoscopic mechanics. In this study, both linear elastic analysis and nonlinear damage analysis are performed; elastic modulus and creep are used as a function of concrete age; and several factors such as temperature difference, multistep cooling mode, and earlier cooling are also studied. The research results show that due to the mesoscopic heterogeneity characteristics of concrete, there is a great deal of difference between homogeneous model and heterogeneous model; pipe cooling can lead to large residual stress around the aggregate and produce a large range of damage, and previous homogeneous model indeed underestimates the effect of cooling-induced stress; using multistep cooling and early cooling mode can reduce this damage; the cooling-induced damage has significant influence on the anti-crack performance of concrete. In the final, based on the research results, the temperature difference between the concrete and pipe water of the second-phase cooling was recommended to be controlled at approximately 5°C.

scholarly journals Temperature Control Technology for Construction of Jinsha River Bridge

2021 ◽  
Vol 2021 ◽  
pp. 1-14
Author(s):  
Hui-Wu Jin ◽  
Guo-An Wang ◽  
Zhan-Ming Chen
Keyword(s):  
Temperature Control ◽  
Temperature Difference ◽  
Cooling Water ◽  
Good Health ◽  
Large Mass ◽  
Maximum Temperature ◽  
Mass Concrete ◽  
Jinsha River ◽  
Mixture Ratio ◽  
Concrete Temperature

The key problem of mass concrete temperature control is to effectively control the maximum temperature inside concrete, the temperature difference between inside and outside concrete, and the temperature difference between surface and environment. The size of the main tower cap of No. 3 Jinsha River Bridge is 37 m × 23.5 m × 5.5 m, and the cubic volume of concrete reaches 4782.3 m3, which is poured in two times. In order to ensure construction quality of mass concrete structure, prevent the large mass concrete temperature stress, through the numerical simulation of the temperature control and optimization scheme, by optimizing the mixture ratio design, reducing the temperature of concrete pouring into the mold, cooling water cycling, insulation keeping in good health and a series of measures to effectively achieve the control goal, and eliminating the temperature cracks. The measured data show that the maximum temperature inside concrete, the temperature difference between inside and outside, and the temperature difference between surface and environment are qualified, but the temperature difference control of cooling water inlet and outlet has hysteresis effect, and the temperature difference between inlet and outlet will be greater than 10°C, which should be noticed.

scholarly journals Precise Simulation of Heat-Flow Coupling of Pipe Cooling in Mass Concrete

Materials ◽  
2021 ◽  
Vol 14 (18) ◽  
pp. 5142
Author(s):  
Peng Yu ◽  
Ruiqing Li ◽  
Dapeng Bie ◽  
Xiancai Liu ◽  
Xiaomin Yao ◽  
...  
Keyword(s):  
Heat Flow ◽  
Temperature Gradient ◽  
Temperature Control ◽  
Cooling Water ◽  
Mass Concrete ◽  
Finite Element Software ◽  
Flow Coupling ◽  
Cooling Pipe ◽  
Cooling Effects ◽  
Precise Simulation

For a long time, temperature control and crack prevention of mass concrete is a difficult job in engineering. For temperature control and crack prevention, the most effective and common-used method is to embed cooling pipe in mass concrete. At present, there still exists some challenges in the precise simulation of pipe cooling in mass concrete, which is a complex heat-flow coupling problem. Numerical simulation is faced with the problem of over-simplification and inaccuracy. In this study, precise simulation of heat-flow coupling of pipe cooling in mass concrete is carried out based on finite element software COMSOL Multiphysics 5.4. Simulation results are comprehensively verified with results from theoretical solutions and equivalent algorithms, which prove the correctness and feasibility of precise simulation. Compared with an equivalent algorithm, precise simulation of pipe cooling in mass concrete can characterize the sharp temperature gradient around cooling pipe and the temperature rise of cooling water along pipeline more realistically. In addition, the cooling effects and local temperature gradient under different water flow (0.60 m3/h, 1.20 m3/h, and 1.80 m3/h) and water temperature (5 °C, 10 °C, and 15 °C) are comprehensively studied and related engineering suggestions are given.

scholarly journals STUDY ON ARRANGEMENT OF COOLING WATER PIPE TO CONTROL HYDRATION HEAT OF CONCRETE IN BEAM OF CABLE-STAYED BRIDGE

2021 ◽  
Vol 30 (2) ◽  
Author(s):  
Long Liu ◽  
Saisai Yu ◽  
Wentao Xu ◽  
Zhilong Wang
Keyword(s):  
Finite Element ◽  
Flow Rate ◽  
Water Flow Rate ◽  
Cooling Water ◽  
Hydration Heat ◽  
Inlet Temperature ◽  
Mass Concrete ◽  
Water Pipe ◽  
Finite Element Software ◽  
Joint Section

The box girder joint section of the Yangtze River Highway Bridge is taken as the research background, and the finite element software MIDAS/FEA is used to simulate the hydration heat of concrete to the layout of cooling water pipe in building mass concrete. The finite element calculation results are in well agreement with the measured data. On this basis, the influence of changing the diameter and distance of the cooling water pipe, the inlet temperature and the flow rate on the temperature of hydration heat is studied. The results show diameter of the cooling water pipe and inlet temperature have a significant effect on the temperature of hydration heat. The change of water flow rate has little effect on the temperature of hydration heat. It provides a reference for the layout of the same concrete cooling water pipe arrangement.

Sign in / Sign up

Export Citation Format

Share Document