FEA And Structural Optimum Of The Chimney With Steel Multi-flue Liners On Basis Of APDL

The multi-flue chimney is one intemational universal chimney of power plants. It has a lot of advantages, but its cost is more than the usual RC chimney's. So, it is very necessary to analyse and optimize the multi-flue chimney.ANSYS which is used quite widely is a large-scale all-purpose FEA software. Specially, its APDL (ANSYS parametric design language) technology is very useful and a good effect can be obtained by skillfully using it. In this paper the useful APDL technology was used in the finite element static and dynamic analysis and structural optimum design of the multi-flue chimney of a power plant.In the first place, a three-dimension model is built up by using software ANSYS to analyse the multi-flue chimney of a power plant and nonlinear static analysis is made. Then, the natural frequencies and modes of vibration are obtained by performing vibration mode analysis. Moreover, two types of seismic calculation methods, that is, response spectrum analysis and time-history analysis are used in this paper. Some results such as the displacement, shear, moment of the structure are obtained and some observations about the results are presented. Finally, on the basis of these analysis results, some optimum researches of the sectional size of the multi-flue chimney are made and a optimum program about it is compiled.A lot of APDL programs are compiled in order to analyse and optimize the multi-flue chimney. Specially, the program about translating stress into internal force is very practical and convenient. By static analysis, stress distribution regulation, the weak part of the structure, the displacements and internal forces are gained. And the influence of the additional bending moment is notable. By seismic analysis, time-history analysis is necessary and other analysis methods are not enough. On the basis of these analysis results, a optimum program involving computing reinforcing steel bar and crack width is compiled. In addition, by using structural optimum design technology of ANSYS, the volume of the optimum steel liner is about half comparing the volume of the original design project.