Steel Buildings in Europe

Part 11: Moment Connections 11 - 2 Table 1.1 Components of the joint to determine the potential design resistance of a bolt row Component EN 1993-1-8 clause number Column flange in bending t,fc,Rd F 6.2.6.4 and Table 6.2 Column web in transverse tension t,wc,Rd F 6.2.6.3 End-plate in bending t,ep,Rd F 6.2.6.5 and Table 6.6 Rafter web in tension t,wb,Rd F 6.2.6.8 The resistance for each row is calculated in isolation. The connection resistance may be limited by:  The design resistance of a group of bolts  The stiffness of the column flange or end plate, which may preclude a plastic distribution of tension forces  The shear resistance of the column web panel  The resistance in the compression zone. Because the tension resistance of a row may be limited by the effects of forces in other rows in the bolt group, the effective design tension resistances are considered to be potential resistances – their full realisation may be limited by other aspects of the design. The potential design tension resistance F t r ,Rd for each bolt row should be determined in sequence, starting from the furthest bolt row from the centre of compression (with the maximum lever arm). In accordance with § 6.2.7.2(4), the resistance of any bolt rows closer to the centre of compression are ignored when calculating the resistance of a specific bolt row, or group of rows. Subsequent rows are verified both in isolation and also as part of a group in combination with rows above. The resistance of row 2 is therefore taken as the lesser of:  the resistance of row 2 acting alone, and  the resistance of rows 1 and 2 acting as a group minus the resistance already allocated to row 1. Row 1 is furthest from the centre of compression, and rows are numbered sequentially. A stiffener in the column, or in the rafter, disrupts any common yield line pattern, which means that groups containing a stiffener need not be verified on that side. In a detail with an extended end plate, such as in Figure 1.1, the flange of the rafter means that there cannot be a common yield line pattern around the top two bolt rows in the end plate. On the column side, however, a common yield line pattern around the top two rows is possible, and must be verified.