ON THE EFFECTS OF CIRCULAR BOLT PATTERNS ON THE ...

configurations of the finite element models of both circular and square bolt patterns of the models with
similar bolt diameter and various end-plate thicknesses are presented in pair and compared in this
section; see Figure 6-18 through Figure 6-21.
The end-plate deformations of the Model Tp½-Bd1-d24 with both circular and square bolt pattern are
presented in Figure 6-18(a) and Figure 6-18 (b), respectively. These figures show no significant different
between the end-plate deformation of the connections with circular or square bolt pattern. Compression of
these two figures reveal that due to the small thickness of the end-plate, majority of the rotation and
deformation occur in the end-plate and the loads are been absorbed by only the close bolts, Bolt-2 and
Bolt-3, while the far bolts remain mostly un-touched.
The end-plate deformations of the Model Tp½-Bd1-d24 with both circular and square bolt pattern are
presented in Figure 6-19(a) and Figure 6-19(b). Using circular bolt pattern on these connections
enhances the energy dissipation of the connection by 29.9%, see Table 6-5. Studying the end-plate
deformation of these connections shows that the connection with circular bolt pattern has a smaller end-
plate separation while the evidence of elongation in Bolt-4 of the model with circular bolt pattern is more
pronounce when it is compared with the model with square bolt pattern, compare Figure 6-19(a) and
Figure 6-19(b).
The end-plate deformations of the Models Tp11 8
-Bd1-d24 and Tp1½-Bd1-d24 with 80.7% and
70.5% energy dissipation variation are presented in Figure 6-20 and Figure 6-21 respectively. By visual
inspection, it can be seen that near bolts undergo more deformation compared with far bolts in the
connection with square bolt pattern, compare Figure 6-20(b) and Figure 6-21(b). Indeed, the end-plate at
the locations of near bolts (Bolts-2 and Bolt-3) has separated from the column flange with visible gap. In
contrast, the deformed shape of the connection with circular bolt pattern Figure 6-20(b), and Figure 6-
21(a) shows less deformation, at the location of near bolts (Bolts-2 and Bolt-3), at the same load level
with the end-plate being mostly intact with the column flange at the locations of the near bolts.
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