The Bending Resistance of Steel Beams

Out‐of‐plane Stability Design by GMNIA – Equivalent Imperfections and Strain Limits

“…In Eqs. ( 1)- (4), εy = fy/E is the yield strain, where E is Young's modulus, Ω is a project specific design parameter that defines an upper bound to the maximum permitted strain, for which the value of 15 is recommended [15], n is the strain hardening exponent, σEd,max is the maximum stress in the cross-section under consideration and 𝜆 ̅ p is the cross-section slenderness, determined from Eq. ( 5):…”

Out-of-plane stability design of steel beams by second-order inelastic analysis with strain limits

“…LT c,Rk cr / λ MM = (4) where α LT is the imperfection factor determined on the basis of the cross-section depth to width ratios, as explained in EN 1993-1-1 [14], β is a modification factor, LT λ is the normalised slenderness, LT,0 λ is the threshold slenderness and M cr is the elastic critical buckling moment.…”

“…1. The influence of LTB on the resistance 2 of steel beams is generally accounted for in design standards by either: (i) the application of a buckling reduction factor to the cross-section bending resistance [1][2][3][4] or (ii) the determination of the elastic buckling moment of the beam with a reduced stiffness [5,[6][7][8][9][10][11][12][13]. The former approach has traditionally been adopted in structural steel design standards [14][15][16][17] owing to its suitability for application through hand calculations [11] and its relative ease of extension to the design of beam-columns through the use of interaction curves [18][19][20][21][22][23][24][25][26][27].…”

Equivalent imperfections for the out-of-plane stability design of steel beams by second-order inelastic analysis

“…There are currently two different sets of LTB curves given in Eurocode 3 [1], referred to as the general case (see Section 2.1.1) and the specific case (see Section 2.1.2). These curves implicitly consider the influence of geometric imperfections and residual stresses in the determination of the buckling reduction factor [3][4][5][6][7]. Alternatively, the LTB design of members can be undertaken more directly by performing a second-order, also referred to as geometrically nonlinear, or advanced, analysis with imperfections.…”