CAG : A CHIMNEY ANALYSIS AND GRAPHICS PACKAGE FOR WIND LOADS

Abstract

The increasing trend towards the construction of tall chimneys and the reduction in shell thickness due to higher allowable working stresses provided in modern design have resulted in the more critical role of wind loads. The very random nature and the dynamic behaviour of wind loading have made the analysis of chimneys for such loading a very difficult task which is almost impossible to be achieved without the help of a computer. Even with the help of analysis program the interpretation.of results from the bulk of output obtained for various loading cases is not easy unless the results are obtained into graphical form. A complete interactive package is thus strongly needed which can analyse the chimney and simultaneously plot-the results. In the present dissertation work a Chimney Analysis and Graphic (CAG) package has been developed and presented in this report. This package analyzes cylindrical chimneys, with constant or varying taper along its height, in both along-wind and across-wind directions. It uses Davenport's approach for along-wind analysis and Vickery's approach for across-wind analysis. In addition to giving the output in systematically arranged tabular form, it plots the results obtained at various stages of analysis, viz., Geometrical properties of chimney; Material, Wind and, Terrain Properties; Mode Shapes; Shear Force Bending Moment and Deflection diagrams and the Deflected Profiles of Chimney.