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

or the beam. This category of the hysteresis is called “End-Plate Behavior” by the author. The tri-linear
hysteresis model of “End-Plate Behavior” category is presented in Figure 5-6.
The second category is the models with relatively small bolt diameter. Due to an early and large
deformation of the bolts in these models, the hysteresis behaviors of these connections are largely
governed by the overall behavior of the bolts in the connections. Therefore, this category of the hysteresis
behavior is called “Bolt Behavior.” The tri-linear hysteresis model of the “Bolt Behavior” category is
presented in Figure 5-7.
Visual observation of the hysteresis results of the models shows that the threshold between the two
hysteresis behavior of the “End-Plate Behavior.” and “Bolt Behavior” is the bolt diameter of ¾ in. The
models with bolt diameter equal of smaller than ¾ in. undergo a large bolt elongation and present “Bolt
Behavior”, while the models with bolt diameter larger than ¾ in. present “End-Plate Behavior”.
To simulate the hysteresis behavior of the connections, four essential parameters were determined
for each model using the results collected from the finite element analysis. These parameters are; the
moment capacity of the connection at yield (My), the initial stiffness (E), the post yielding stiffness (Et), and
the maximum rotation of the end-plate at the failure (θf). Figures 5-6 and 5-7 show the schematic drawing
of the tri-linear hysteresis model and the corresponding parameters for connections with “End-Plate
Behavior” and “Bolt Behavior” respectively.
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