In general, the bolt rows of extended end-plate joints are characterized by different failure modes.
The comparison of such curves corresponding to several different beam-to-column joints allowed for developing closed-form approximate equations for the initial stiffness and resistance of extended end-plate joints.
The end-plate thickness was assumed equal to the column flange thickness (i.e., [t.sub.p]/[t.sub.fc] = 1).
Hypotheses about the stages of the performance and the reaction of end-plate connections due to increase in temperature are shown in Figures 3 and 4.
The purpose of Figures 3 and 4 is to show that movement tolerance at the surface of end-plate connection can absorb part of the movement in the end of the beam due to elongation.
In order to simplify the calculation in two-dimensional (2D) model, joints in the end-plate connections are assumed to be rigid.
In calculations of this type of joints, similarly as in Case 2, behaviour of column web panel in shear, column web in transverse compression and tension, column flange and end-plate in bending, bolts in tension have to be taken into account.
Because of their geometry, these joints with an unextended end-plate and tensile bolt row below the beam flange have to be more flexible and weaker than the joints with an extended end-plate (Case 2).
Furthermore, calculations of joints were performed when the components in the connection area were less stiff: bolt diameter was reduced to 16 mm and the end-plate thickness up to 10 mm.
The acting of the load is in increment of one kN at the moment when the nonlinear effect in the end-plate appears.
Moment-rotation (M-[PHI]) diagram of the end-plate is obtained by the horizontal displacements (Figure 12) of the two characteristic points of the end plate.
The two characteristic point of the end-plate from which the moment-rotation diagram is obtained are the points in the centre of the two flange (Figure 13).