Dissertation > Excellent graduate degree dissertation topics show

Simulation and Study on Temperature and Stress Fields for Mass Concrete Structure

Author: ZhangXiaoFei
Tutor: ChenYaoLong；LiShouYi
School: Xi'an University of Technology
Course: Hydraulic Structure Engineering
Keywords: Large concrete structures Cooling pipes Surface insulation Jump positions pouring Inverse Analysis
CLC: TU375
Type: PhD thesis
Year: 2009
Downloads: 658
Quote: 3
Read: Download Dissertation

Abstract

Temperature field and thermal stress analysis of large concrete structures, temperature control and crack prevention measures is an important issue in the design and construction of a simulation study of the temperature and stress field of massive concrete structures has important practical significance. The simulation of the temperature stress and the structure of large concrete structures, climatic conditions, the construction process, material properties, and operating conditions and other factors have a close relationship. External security \reduce the the highest dam internal temperature; site for the construction of low-temperature season, or when the dam suffered cold wave, often need to take surface insulation measures to reduce the maximum temperature difference of the dam surface, thereby reducing the tensile stress of the surface of the dam. Therefore, for the study of the cooling water pipes and surface insulation method has important practical value. In this paper, based on heat conduction theory and finite element method to build simulation construction process simulation calculations mathematical model proposed in concrete cooling water pipe layout area using cooling water pipes structural finite element method, a three-dimensional finite element floating Mobility cell outside the cooling water pipe layout area Law, with an emphasis on the three-dimensional finite element mesh floating method with cooling water pipes substructure coupling method; departure from the principle of heat balance at the same time, directly to the thermal conductivity of the surface heat coefficient and heat as the temperature of the basic parameters of the heat conduction equation is derived field finite element equation, so that more reasonably reflect the temperature field of the large difference in material composition by a variety of thermal performance composite structures, systematic study of the law of large concrete structures surface insulation thermal conductivity, thermal or coefficient method and equivalent thickness. Second, large concrete structures hierarchical block jump positions pouring to increase the cooling area and reduce the actual situation of pouring block size, proposed using Ansys software to create a finite element model, and developed its own language based on Fortran Temperature Control Simulation program simulation calculation of temperature field and thermal stress Sufer software processing methods to achieve temperature control simulation of arbitrarily complex structure; Finally, large concrete structures thermostat during the calculation, due to laboratory test parameters very difficult reaction authenticity of the construction site concrete the practical problems, using three-dimensional finite element relocating mesh method and variable tolerance method of concrete thermal parameters back analysis, to be reflected in concrete real thermal performance parameters, can be used forecast, guidance works. The research paper can be convenient, fast, and accurate calculation of the laying of cooling pipes, taken under the conditions of surface the insulation and jump positions pouring large concrete structures of the temperature field and thermal stress. At the same time, the measured temperature data, combined with the construction site to determine the thermodynamic parameters of concrete by reverse analysis. Provide a scientific basis for mass concrete structure temperature field and temperature stress, and also provide a theoretical basis for further study of the mass concrete temperature control.

Related Dissertations

CLC: > Industrial Technology > Building Science > Building structure > Concrete structure,reinforced concrete structure > Reinforced concrete structures
© 2012 www.DissertationTopic.Net Mobile