# A Review of the T-Stub Components for the Analysis of Bolted Moment Joints
## 3 Experimental Testing
The specimens were characterised by different values of the ratio between the flexural resistance of the flanges and the axial resistance of the bolts (notice that the flexural resistance of the bolt was not taken into account). The results were compared with the theoretical model with the force displacement curve. This comparison reveals a satisfactory degree of accuracy and, as a consequence, constitutes the validation of the proposed theoretical model. In 2001, [PERSON] and [PERSON] [38] studied the behaviour of T-stub connections that work at high temperatures due to the fact the ability of the joints to sustain loadings is considerably impaired [39]. The tests employed a furnace, where the T-stubs were heated at a temperature above 300 \({}^{\circ}\)C and under 800 \({}^{\circ}\)C, and then tested. The displacement of the specimens was taken with a solid-state charge-coupled device (CCD) camera. Even though when the investigation was focused on the suitability of the CCD measurements, the results of the tests showed that the ultimate resistance at 600 \({}^{\circ}\)C decreased more than 56% of the resistance at ambient temperature. In 2004, [PERSON] et al. [40] carried out 32 tests on T-stub bolted connections made up of welded plates at the Delft University of Technology. The investigation provides insight into the behaviour of different types of assemblies in terms of resistance, stiffness, deformation capacity and failure modes. The variables that were taken into account were the following:  
* The weld throat thickness. * The size of T-stub. * The steel grade. * The presence of transverse stiffness and the T-stub orientation. These tests unveiled that the welding procedure is essential to develop a ductile behaviour in the connection. The major contributions of the overall T-stub deformation are the deformation of the flange and the bolt deformation. Most of the time, the maximum deformation is reached when the T-stub flange cracking happens before the bolt cracking. However, flange cracking could happen before the connection develops its theoretical deformation because the welding procedure could change the microstructure of the flange in the HAZ. Therefore, the mechanical properties could decrease by 20%. Finally, it was concluded that the thickness of the throat affects the stiffness and the resistance of the  
Figure 19: Typical T-stub configuration tested [35]. connection in a direct proportion. The effect of the width affects the stiffness and the resistance directly as well. Higher bolt diameter increases the bolt resistance and enhances the resistance, stiffness and ductility of the connection; identical T-stubs yield higher resistance and lower deformation capacity for higher steel grades. The stiffener decreases the deformation capacity. Moreover, for stiffened T-stub, the orientation of the elements is not relevant at the stiffener side; in the case of untiffened T-stub, the two plates become in contact when a tensile load is applied to the connection. In 2008, [PERSON] et al. [41] performed a series of experimental testing at the Material and Structure Laboratory of the Department of Civil Engineering of Salerno University to validate a new refined theoretical model of an earlier (2001) model that was mentioned above [37]. Because of the lack of precision of the original theoretical model to predict the plastic deformation capacity according to failure mode 2, some improvements were implemented in the original model, such as the bolt preloading and the effects of bending on the bolts were not disregarded. The experimental results were compared with the two theoretical models with the force-displacement curve and showed that the refined model's ultimate force coincided with the experimental value. However, the ultimate displacement was not the same due to bolt ultimate strain was taken as the lower value provided by the manufacturer.