Mc Rd is the moment resistance of the cross-section given in 5.4.1(1)P; Vw Rd is the shear resistance of the web given in 5.8(1)P.

5.11 Combined bending moment and local load or support reaction

(1)P Cross-sections subject to the combined action of a bending moment AfSd and a transverse force due to a local load or support reaction FSd shall satisfy the following:

A*Sd/A*c,Rd * 1 |
... (5.26a) | |||||||||

^Sd^w.Rd - 1 |
... (5.26b) | |||||||||

MSà ^ FSd ^ ^ |
... (5.26c) | |||||||||

Mc Rd is the moment resistance of the cross-section given in 5.4.1(1)P; *w Rd is the appropriate value of the local transverse resistance of the web from 5.9. Page 62 ENV1993-1-3 s 1996 6 Buckling resistance 6.1 General (1)P The design values of the internal forces and moments in each member shall not exceed its design buckling resistance to: - axial compression, as given in 6.2; - combined bending and axial compression, as given in 6.5. (2)P In members with cross-sections that are susceptible to cross-sectional distortion, account shall be taken of possible lateral buckling of compression flanges and lateral bending of flanges generally, see 6.4. (3)P The effects of local buckling shall be taken into account by using effective section properties determined as specified in Section 4. (4)P The internal axial force in a member shall be taken as acting at the centroid of its gross cross-section. (5) The resistance of a member to axial compression should be assumed to act at the centroid of its effective cross-section. If this does not coincide with the centroid of its gross cross-section, moments corresponding to the shift of the centroidal axes (see figure 6.1) should be taken into account, using the method given in 6.5. (6)P Frame instability shall be taken into account as specified in ENV 1993-1-1. Figure 6.1: Shift of centroidal axis Figure 6.1: Shift of centroidal axis 6.2 Axial compression ## 6.2.1 Design buckling resistance(1)P Unless determined by a second-order analysis of the member, see 6.2.2(6)P, the design buckling resistance for axial compression NbRd shall be obtained from: the effective area of the cross-section, obtained from Section 4 by assuming a uniform compressive stress acom Ed equal to fyb/ym; the area of the gross cross-section; the appropriate value of the reduction factor for buckling resistance, in which the reduction factor 0A is given by: (2)P The reduction factor x for buckling resistance shall be determined from: with: where: a is an imperfection factor, depending on the appropriate buckling curve; X is the relative slenderness for the relevant buckling mode. (3)P The lowest value of x for flexuiral buckling of the member about any relevant axis, or for torsional or torsional-flexural buckling, shall be used. (4)P The imperfection factor a corresponding to the appropriate buckling curve shall be obtained from table 6.1.
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