# A Review of the T-Stub Components for the Analysis of Bolted Moment Joints
## 6 T-Stubs of Non-Conventional Steel and Other Materials
The simulation results showed that the FEM model reproduced with good accuracy the tests in terms of stiffness, resistance and ductility. Finally, the researchers evaluated the viability of the  
Figure 30: Scheme of the proposes of the numerical-informational model [78]. “Reproduced with permission from [PERSON], [PERSON], [PERSON], [PERSON], Engineering Structures; published by Elsevier, 2015”. EC9 for predicting the T-stub behaviour. Therefore, the EC9 predictions were compared against experimental data. This comparison showed that the EC9 predictions were slightly conservative in predicting the strength, and the prediction could be improved through a more precise evaluation of the effective width. In 2012, [PERSON] et al. [90] developed a FEM model which was calibrated with available experimental data from the literature [86] and performed a parametric study of 43 simulations of welded T-stubs made of aluminium, which had different configurations and types of bolts (grade 4.8, 10.9 and 7075 alloy bolts) to analysis all the possible failure modes. The simulations were carefully developed to compare with the EC9 and to check the reliability of the design standard method. The EC9 proposes four failures modes to describe the behaviour of welded T-stub made of aluminium. The comparison of the parametric study results and the prediction of the EC9 showed that the EC9 k method predicted with good accuracy the behaviour of aluminium-stubs connected with weak bolts, and the EC9 overestimated the ultimate strength when thick T-stub flanges and large bolt pitches are used, especially when failure mode 1 appears because it is quite related to the \"effective length\" concept. Additionally, the authors proposed a further study to check the reliability of the EC3 formulation for the \"effective length\". In 2017, [PERSON] et al. [91] studied the effect of the welding on the tensile performance of high strength steel (HSS) RQT S690 T-stub Joints. Therefore, three types of T-stub (flange thickness equal to 8, 12 and 16 mm) made of RQT S690 and one type of T-stub (flange thickness equal to 16 mm) made of normal strength steel (NSS) S385 were fabricated twice (a total of eight T-stub) according to AWS structural steel welding code. Additionally, to the experimental testing, the investigation was focused on developing two FEM model (for each type) that could predict the behaviour of the T-stubs. The first FEM model did not consider the effect of the welding, and the second model took into account the effect of the welding (HAZ). Therefore, the first step was to perform a transient thermal analysis employing a FEM model to obtain the time-depending temperature distribution field, where the heat source that was utilised for the simulation was the body heat source model base on [PERSON]'s double ellipsoid heat source model theory [92]. Secondly, the time-dependent temperature distribution data was used as a thermal loading in the mechanical analysis to simulate the alteration in the mechanical properties and subsequent tensile test. This investigation determined that the experimental Force-displacement curves of the T-stub of two different materials had the same pattern. Also, the suitability of the EC3 design resistance prediction equation was evaluated, and it was observed that the EC3 accurately predicted the first yield resistance of the T-stub made of S385 but overestimated the behaviour of the RQT S690 T-stub. This overestimation was attributed to the changes in the material's mechanical properties due to the welding process. The FEM analysis confirmed this attribution, and it was observed that the FEM model that considered the effects of welding reproduced with more accuracy the T-stub behaviour than the T-stub that not considered the welding effect. In 2018, [PERSON] et al. [93] studied the effect of welding and complex loads on T-stubs made of high strength steel (HSS). The main HSS microstructure is composed of martensite and bainite, which are not stable at high temperatures [94].