Static Analysis And Stability Of Large Cylinder-conic Section Steel Cooling Towers

Cooling tower is an important building which is widely applied to the recirulating cooling water in thermal power plants.It has environmental protection,energy-saving and security characteristics.Because of the steel structure cooling tower has the advantages of light weight,fast construction speed and reusable.steel structure has become a new direction for large-scale cooling tower structure selection.At present,less research achievements of steel structure cooling tower.There is no relative standard line to refer.Therefore,it is necessary to carry out in-depth research.According to practical size of one project of a cylinder-conic section steel cooling tower,finite element model is established by means of software SAP2000.This paper mainly analyzes the static and dynamic loading,stress analysis at the critical nodes and integral stability analysis.The main contents of this dissertation include:1、This paper presents a computational method of computation and principle for using the box-section thin-walled element to equivalent square columns consisting of four steel angle.The theoretical calculation formulas of its axial rigidity,bending stiffness,shear rigidity torsional stiffness is derived.Based on the formulas,box-section thin-walled elements are constructed and the comprehensive stiffness correction factor is given.Using the finite-element method of the cantilever beam to analysis and calculation.The result has shown that the box-section thin-walled elements can meet engineering precision requirement.Finaly,making use of box-section thin-walled elements to build the cylinder-conic section steel cooling tower model.2、Under the existing norms and rules,the mechanics performance of steel structure cooling tower is calculated in conditions of self-weigh load,wind load,temperature,earthquake load and combined operating conditions.We can conclude the control load and the most unfavorable load case of the structure.3 、 According to the theory of standard for design of steel structures(GB50017-2017)of stability formula.Basing on load negative stiffness,we derived the formulas for stability design and effective length coefficient formulas which applicable to generally space structure.The formulas can consider support each other easily of space structure.The support capability each other also be thought over between the layers.In this paper,we analyze the support capability of stiffener ring truss and structural lateral stiffness in the inclined columns of the tower wall and calculating methods are given.The steel structure cooling tower also be made the overall elastic buckling analysis by using of SAP2000.