System Optimization And Static Analysis Of Steel Cooling Tower

The steel structure cooling tower has the advantages of light weight,high assembly efficiency,fast construction speed and environmental protection.With the increasing of the shape of new cooling towers,steel structure has become a new direction for largescale cooling tower structure selection.At present,most of the scholars study the seismic behavior,construction technology and so on of the steel structure cooling tower,mainly based on the engineering examples.Scholars seldom study the steel structure cooling tower system.Therefore,it is necessary to carry out in-depth research,study and design a reasonable economic steel tower system to provide technical conditions for practical engineering applications.The main contents of this dissertation include:1.Four kinds of large-scale steel structure cooling tower system are proposed: the latticed shell system of double-layer pyramid,the latticed shell system of double-layer parallel truss,the shell system of single-layer rectangular grid and the shell system of single-layer triangular grid.Based on the APDL parametric language of ANSYS,the automatic generating programs,the load program and the bar selection program for four kinds of steel structure cooling tower system are compiled,which lays a good foundation for further research.Based on 6 different load combination conditions,the static analysis of the four systems is completed.The load conditions that control the systems are summarized.The mechanical properties of four systems under the action of self weight,wind load and temperature load are studied.The internal force distribution law of each system is summarized.2.Considering the geometrical nonlinearity and material nonlinearity of the structure,the stability analysis of four kinds of steel structure cooling tower system is carried out,and the failure modes of each system are studied.In view of the weak stability of single layer system,five strengthening schemes were proposed and the optimum strengthening scheme was obtained by comparing and analyzing.3.Setting the grid size and the shell thickness as parameters,at the height of 220 m,124m and 90 m,a great number of parameter analysis including 266 models are studied.The variation of mechanical properties of four systems with the above parameters is summarized and the reasonable range of parameters is summed up,which provides a reference for the theoretical research and engineering design of large-scale steel structure cooling towers.Static behaviors including amount of steel weight,peak displacement and peak stress of the four systems were compared.The results show that the double-layer pyramid system has best mechanical performance with the same height and loads.Three supporting structures of “X” column,inverted “V” column and “V” column are designed respectively,and the influence of different support structures on the mechanical properties of the steel structure cooling tower systems is studied.Considering the safety and economic performance of the structure,the "X" column is proved to be the best support.