Program for finite element analysis of grillages with circumferential arc-shaped and straight elements

Resumo

This paper presents the development of a program for structural linear-elastic analysis of grillages with
circumferential arc-shaped elements and regular straight bars under concentrated and distributed loads. It was
based on the Finite Element Method, and the code was written in FORTRAN (FORmula TRANslation). The force
method was used initially to calculate the flexibility matrix and then by inversion the stiffness matrix and load
vectors were determined. Results of deflections, rotations, bending, torsion and shear, from numerous examples
were checked against some of those available in the scientific literature, in order to validate the code. A comparison
was also made with the validation results and those calculated by the virtual work method, or extracted from two
similar softwares where the curved bars needed to be approximated by various small straight elements. The
program developed was shown to give closer values to the exact solution, with a much simpler input data (just
angles and radiuses), than the other softwares.