COMPUTER AIDED STATIC ANALYSIS OF ANTENNA STRUCTURES FOR WIND LOADS

Abstract

The work presented here deals with Computer Aided analysis of back-up framed structure for a dish type antenna with a paraboloid surface. The predominant load coming on antennas is the wind load. The structure has been analysed for two positions of antenna , vertical and zenith, for different orien-tations w.r.t. wind direction (00, 30o, 60°, 90°). The structure has been analysed as a pin-jointed space frame using matrix displacement method. A generalised computer program has been developed for the analysis. This program includes a segment for automatic mesh generation, which generates the required data for the analysis program. Another segment in the program computes the equivalent nodal loads from the given pressure distribution on the antenna surface for various orientations of the antenna. The program also computes the equivalent nodal load due to self weight. It also determines the r.m.s. surface error after fitting a best-fit-paraboloid through the deflected o An ware package supplemented by AutoCAD has been veloped lisplay of the antenna structures from the generated Lta. Chapter 2 contains the design considerations while in chapter 3 wind loads for such structures are discussed. In chapter 4, the method of analysis is discussed, chapter 5 deals with the software developed for analysis and plotting. With the help of an example, details and results are given in chapter 6. The last chapter contains the conclusions.