Disign Method Improvment And Finite Element Analysis For 600MW Boiler Plate Girders

Boiler main girder is the most important load-bearing element in the steel structure power plant.As its large size,heavy load action,high requirements of manufacture and installation,the design and calculation of main girder is always an important issue for the steel structure design.The traditional theoretical analysis has not met the current rapid development of boiler capacity.In this dissertation,through the ANSYS software by the method of finite element analysis,it simulated the main girder,improved the traditional theoretical analysis and calculation,and increased the amplification coefficient.All the above is to satisfy the strength requirement of main girder calculation.The comparative analysis of main girder with actual engineering structure and simulation structure was simulated by using finite element software,stress of different load status and structure condition,this proves the reliability of existing structures and stability of structural,and also made a theoretical basis to the future modification.The main girder installation conditions are simulated,compared with the design specifications,clearly the influence of installation error to the girder overall stability and safety factor.To assist the site girder installation,the minimum pre-arched value and pre-arched form of the main girder are also analyzed.In considering the influence of different depth-span ratio to the analysis of main girder,the safety factor had been proposed to simply supported beam theory.That is to say,the main girder deflection amplification factor is 1.18,the main girder normal stress amplification coefficient is 1.6,and the maingirder shear stress amplification coefficient is 2.0.Based on the results of numerical simulation,China steel structure code(GB50017-2003),and America steel structure design code(ASD),some suggestions are proposed to the power plant using the simply supported beam theory.The normal stress level of the main girder should be controlled,and the limit deflection should be 1/1000 of the length of main girder.