ABSTRACT
Determine the force on the most heavily loaded bolt in the beam-to-beam connection illustrated in Figure 8.2 assuming a beam end reaction of 180 kN.
Solution Force per bolt due to vertical shear = 180/4 = 45 kN / for bolt group about horizontal axis of bolt group = 2[3.52 + 10.52] = 245 cm4 Z for outermost bolts = 245/10.5 = 23.33 cm3 M due to eccentricity of line of bolts from centreline of beam = 180 X 0.045 = 8.1 kN m Force on outermost bolts = 45 kN vertical + 8.1 X 102/23.33 horizontal
= 45 kN vertical + 34.76 kN horizontal Resultant force = [452 + 34.762]* = 56.86 kN
More sophisticated approaches, in which the true nonlinear load-deflection response of the bolts is used to locate the instantaneous centre of the bolt group by trial and error, are available [6,11]. However, experimental work [13, 14] suggests that the difference in accuracy is insufficient to warrant the additional calculations. Since the presence of notches reduces the amount of lateral restraint provided [1], its effects upon the beam's overall bending strength as discussed in Chapter 5 should also be taken into account.
