Research On Temperature Field And Temperature Distortion Of High-speed Maglev Track Concrete Beam And Composite Beam

With the development of China’s transportation industry,the research on high-speed maglev has become another important research direction.In order to ensure the smooth operation of maglev trains,the maglev track beams had strict requirements on ride comfort.This required us to study deeply the temperature field distribution and temperature distortion of high-speed maglev track beam.The work and results of this thesis were shown as follows:(1)Based on the temperature field theory of bridge structure,the differential equation of thermal conductivity and its initial conditions and boundary conditions were derived.The experimental model of Changsha maglev concrete beam and Changsha Hexi combined beam was established,which verified the accuracy of the thermodynamic boundary conditions;(2)By comparing the fitting degree of the normal Copula,t-Copula and Archimedes Copula models,it was determined that the Frank Copula function model describes the relationship between atmospheric temperature and solar radiation.And the extreme values of the joint distribution of atmospheric temperature and solar radiation in Qingdao,Nanjing and Guangzhou were obtained;(3)The finite element models of single or double track concrete beams and simply supported composite beams with spans of 24.968 m and30.96 m were established.By analyzing the distribution law of temperature field,calculating and comparing the temperature effect and obtaining the daily variation process of temperature deformation,it was found that the temperature mode of concrete beam and composite beam in Chinese code is conservative;(4)By analyzing the influence of heat transfer coefficient and solar radiation absorption coefficient of bridge structure on temperature effect,it was found that the influence of wind speed is small.But the solar radiation absorption coefficient had a great influence on the temperature effect of bridge.Therefore,it was recommended to apply light color coating on the surface of bridge structure.176 figures,40 tables,80 references...