John P. Papangelis

Computer analysis of thin-walled structural members

Abstract The calculation of the stresses and failure modes in thin-walled structural members is a complex procedure. Structural designers will often need help in analysing these types of structures. A vehicle for providing this help is the computer program developed for the microcomputer. In this paper, a computer procedure is described for the cross-section analysis and elastic buckling analysis of thin-walled structural members. The cross-section analysis calculates the section properties, warping displacements, and the longitudinal and shear stresses for thin-walled open and closed cross-sections of any shape. The longitudinal stresses are used to perform an elastic finite strip buckling analysis of thin-walled structural members. The analysis can be done for a number of different buckle half-wavelengths of the member and the load factor and buckled shape are output for each length. The analysis is performed by the user-friendly computer program THIN-WALL, which is also described in the paper.

ELASTIC FLEXURAL-TORSIONAL BUCKLING OF STRUCTURES BY COMPUTER

Abstract Flexural–torsional buckling considerations usually control the design of unbraced steel beams and beam–columns. Although there are many sources of information on elastic buckling, these are not comprehensive, and often difficult to access. This paper describes and exemplifies a single comprehensive source of information, the computer program PRFELB for the elastic flexural–torsional buckling analysis of a wide range of beams, beam–columns, and plane frames. PRFELB is a user-friendly computer program, with menus and data and help screens that advise and assist in data input. Graphics can be used to check the geometry and to display the buckled shapes. The use of PRFELB will assist designers to implement the method of design by buckling analysis which is permitted in modern structural steel design standards, either explicitly or implicitly.

Buckling of monosymmetric arches under point loads

Abstract A finite element procedure is described for analysing the flexural-torsional buckling of arches of monosymmetric cross-section. First an inplane analysis is performed to obtain the distributions of axial force and bending moment in the arch. These are then substituted into the buckling equation for monosymmetric arches, and the resulting eigenvalue problem is solved numerically. Higher order quintic shape functions are used to describe the element displacement fields. The effects of the distances from the arch shear centre axis of point and uniformly distributed loads are also included in the analysis. Flexural-torsional buckling tests on circular aluminium arches of monosymmetric I-section are also described. The test results for arches subjected to central concentrated point loads are compared with the finite element theory.