The Track Beam Temperature Load Studies Based On Meteorological Factors

Track beam in a complex natural environment, the long-term by solar radiation, atmospheric temperature changes and other external meteorological factors significantly impact generated under extreme weather conditions of the temperature effect is even more than the dead load and live load effect and meteorological factors as the analysis of one of the key parameters sunshine environment temperature load of the concrete structure?Studies show that most meteorological factors as random variables change over time, affecting rail beam temperature and meteorological factors the main atmospheric temperature and solar radiation, so the temperature of the track beam load as random on the atmospheric temperature and solar radiation variable functions.Based on solar thermal use of the principle, the use of Fortran solar radiation to reach the surface of the track beam parameters will affect the program operation, the track beam surface global solar radiation, and to amend its shadowing effect will eventually solar radiation into the surface of the track beam equivalent temperature load. And use of the two-dimensional finite element heat conduction equation, the establishment of a mixed set of solar radiation and convection heat transfer boundary conditions, the transient temperature field numerical model to build rail beam by ANSYS parametric design language APDL Calculation, it is possible to directly determine whether the appearance of the track beam received solar radiation and radiation size, greatly reduce the amount of work in the pre-treatment manual input of outside parameters of the traditional numerical model to improve the speed of modeling. Found to verify the accuracy of the numerical model to provide a guarantee of reliability for subsequent calculations.Moments of random variables through a single numerical integration methods, to establish a direct relationship between the outside of the track beam meteorological parameters and the structure internal temperature load statistical properties, the statistical characteristics of the track beam structure design reference period temperature load calculation method. Text for the study, the Shanghai maglev track test beam the Shanghai area 32 years of meteorological parameters (air temperature, solar radiation), the cumulative probability distribution curve fitting, and KS verify results show that the meteorological data are subject to the double exponential extremum ?-type distribution. Using weighted Gaussian integral formula to establish the atmospheric temperature, solar radiation between the internal temperature load probability statistical model, the statistical characteristics of the temperature loads calculated by the statistical characteristics of meteorological factors, and its return period of 50 years and 100 years of extreme value prediction. Transform sensitive parameters of the different meteorological conditions, according to the different sensitive parameters set 24 kinds of working conditions, the statistical properties of the meteorological factors were used to calculate the statistical characteristics of each temperature load conditions, and extreme value prediction.