Moment-Curvature-Thrust Relationships for Beam-Columns. (August 2017)

• Record Type: Journal Article
• Authors: Liew, Andrew; Gardner, Leroy; Block, Philippe
• Is Part Of: Structures. Volume 11(2017)
• Page Start: 146
• Page End: 154
• Publication Date: 2017-08
• Subjects: Moment curvature thrust -- Curves -- Cross-section -- Metal -- Beam -- Column -- Plated -- Hollow sections; Structural engineering -- Periodicals; 624.1
• DOI: 10.1016/j.istruc.2017.05.005
• Languages: English
• ISSNs: 2352-0124

Abstract

Abstract: Moment–curvature–thrust relationships ( M – κ – N ) are a useful resource for the solution of a variety of inelastic and geometrically non-linear structural problems involving elements under combined axial load and bending. A numerical discretised cross-section method is used in this research to generate such relationships for I-sections, rectangular box-sections and circular or elliptical hollow sections. The method is strain driven, with the maximum strain limited by an a priori defined local buckling strain, which can occur above or below the yield strain depending on the local slenderness of the cross-section. The relationship between the limiting strain and the local slenderness has been given for aluminium, mild steel and stainless steel cross-sections through the base curve of the Continuous Strength Method. Moment-curvature-thrust curves are derived from axial force and bending moment interaction curves by pairing the curvatures and moments for a given axial load level. These moment–curvature–thrust curves can be transformed into various formats to solve a variety of structural problems. The gradient of the curves is used to find the materially and geometrically non-linear solution of an example beam-column, by solving numerically the moment–curvature ordinary differential equations. The results capture the importance of the second order effects, particularly with regard to the plastic hinge formation at mid-height and the post-peak unloading response.