NASTRAN Data Generating Programs and Analytical Models for Analysis of Antenna Mast and Tower Structures.

摘要

This report is concerned with the development of data generating programs and analytical models to facilitate the structural analysis of antenna mast and tower structures subjected to static and dynamic loadings. The programs generate the data cards necessary to define the structure geometry and material properties of typical masts and towers for the NASA Structural Analysis Program (NASTRAN). The automatic data generating program for masts can be used to model any mast of constant cross section and can handle any number of cable tie points and anchor points;deform cards to duplicate cable pretension are also generated as well as the force cards needed for representing a uniform wind type pressure. The automatic data generator for towers generates a series of tower stages and considers four (4) variations of tower geometry,three (3) possible base conditions and any number of sides greater than two (2). This program was designed for towers with regular generation properties and equal side lengths,but a separate program enables some variations in side length to be considered. In order to provide an economical but efficient NASTRAN model for analyzing antenna towers,three models,with varying degrees of exactness were investigated using several NASTRAN rigid formats for analysis. The capabilities and limitations of these models,with respect to the rigid formats considered,was studied. (Author)