Steel Buildings in Europe

Part 11: Moment Connections 11 - 5 The effect of this limitation is to apply a triangular distribution of bolt row forces. 1.4 Resistance of the compression zone 1.4.1 General The design resistance in the compression zone may be limited by:  The resistance of the column web ( F c,wc,Rd ), or  The resistance of the beam (rafter) flange and web in compression ( F c,fb,Rd ). The relevant clauses of EN 1993-1-8 are given in Table 1.2. Table 1.2 Joint Components in compression Component EN 1993-1-8 clause number Resistance of column web F c,wc,Rd 6.2.6.2 Resistance of the beam (rafter) flange and web F c,fb,Rd 6.2.6.7 1.4.2 Column web without a compression stiffener Ideally, stiffeners in the column should be avoided, as they are expensive and can be disruptive when making connections in the minor axis. However, stiffeners in the compression zone of a column are usually required, especially in a portal frame eaves connection. In a portal frame, the bending moment is large, producing a large compression force, and the column is usually an I- section with a relatively thin web. The design resistance of an unstiffened column web subject to transverse compression is given by EN 1993-1-8, § 6.2.6.2. The design resistance is based on an effective width of web in compression, with the web verified as a strut, and with a reduction factor ω for shear and a reduction factor ρ for longitudinal compressive stress in the column. 1.4.3 Column web with a compression stiffener The design resistance of a stiffened column subject to transverse compression may be calculated in accordance with § 9.4 of EN 1993-1-5. 1.4.4 Beam (rafter) flange and web in compression The compression resistance of the beam flange and adjacent web in compression is given in § 6.2.6.7 of EN 1993-1-8 by:   fb c,Rd Rd, c,fb, h t M F   where: h is the depth of the connected beam