ABSTRACT
3.3 Experimental results As noted from Figure 6, the behaviour of 83 using H8BB fasteners appears to be similar to that of 81 employing A325 bolts, with its initial stiffness slightly higher and its ultimate moment capacity slightly less. The slightly higher initial stiffness of connection 83, may be attributed to the high and consistent clamping force of the H8BB. During the later stages of loading, significant bending took place in the end-plate and in the exterior H8BB bolts on the tension side of the connection, causing partial failure of their primary sleeves. The column flange thickness of 12.7 rom seemed to be just adequate to sustain the bolt force without shearing the column flange underneath the primary sleeve. At ultimate load, a cleavage crack was initiated in 81 at the toe of the weld between the end-plate and the tension beam flange, which eventually propagated through the end-plate thickness to cause a sudden drop in load carrying capacity. Meanwhile, 53 suffered from a brittle failure in the heat affected zone of the beam flange near the end-plate. On the other hand, specimen 82 showed poor performance due to the BOM bolts' premature failure. This result was not unexpected since the nominal tensile strength of the BOM bolt is less than that of A325 by about 30%.
