Second-order analysis and design of angle trusses, Part II: Plastic analysis and design

Abstract

Collapse analysis and design for robustness require information on ultimate or failure surface of sections. The method is not limited to elastic range and the linear interaction equation for stress being not greater than yield stress is abandoned. In this paper, the failure surface for an angle section under combined axial force and bi-axial moments is developed and incorporated into software for second-order plastic analysis of angle frames. Member imperfections, semi-rigid joints and eccentric connections detailed in Part I of the companion paper are also included in the analysis. Same as in the case of the Part I companion paper, this Part II paper is targeted at the introduction of a design method, which is based on the elastic theory in Part I and on the plastic theory in Part II, readily used for practical design instead of a finite element refined analysis of a structural assemblage which appears to have been well studied by numerous researchers. The findings are believed to be useful for developing a robust design and collapse analysis tool for the widely used angle trusses and skeletons.