Citation

Abstract

One type of azimuth bearing for a large ground antenna (100 m) will consist of steel wheels, mounted at four corners of the alidade, rolling on a circular flat rail which provides the vertical restraints; a radial constraining bearing at the center of the alidade provides the horizontal restraints. One important design feature is the compressive stresses in the grout or concrete foundation under the wheel-rail load. This report describes a finite element analysis check of a particular design by H. McGinness that consists of a steel rail resting on a concrete foundation. Symmetry is assumed as much as possible in order to minimize the models, but meaningful element sizes are used. Recently developed isoparametric hexahedron elements available in the NASTRAN computing program, which minimizes the number of elements required while maintaining the accuracy of the computed stresses, are used with two versions of NASTRAN. Test cases to check with the analytical solutions are made. A side loading is also applied to calculate the increase in the concrete Stresses.

Details

Volume
42-43
Published
February 15, 1978
Pages
204–215
File Size
623.5 KB