Analytical frame approach for the axial stiffness prediction of preloaded T-stubs

Analytical frame approach for the rotational stiffness prediction of beam-to-column angle connections

“…For the recently proposed frame approaches [13,14], a 2D representation of the T-stub problem was adopted. The idealization suggested by Annex J of Eurocode 3 consists in modelling the top angle as a bolted Tstub whose width is equal to half of its geometrical width.…”

“…In the case of the preloaded T-stubs ( Fig. 1b), based on the assessment of advanced 3D Finite Element models [14], the preloading condition was imposed by constraining the rotational degree of freedom of the central node. In this case, the second moment of area of the bolt is disregarded.…”

“…In the case of preloaded T-stubs, the axial stiffness solution for preloaded T-stubs [14] was given by the next expression:…”

“…Faella et al [10] had proposed the evaluation of the effective width for stiffness calculations considering an equivalent cantilever whose section was based on a 45°spreading of the concentrated action due to the bolts, starting from the bolt edge. In recent research, two proposals, based on finite element parametric studies, have been suggested to evaluate the T-stub effective width relating to stiffness calculations [13,14]. These approaches, introduced in the analytical frame solutions described in Section 2, have been validated by comparisons with the experimental results from Faella et al [10] and Bursi and Jaspart [15] for preloaded and non-preloaded T-stubs, proving to be satisfactory in most cases.…”

“…In order to achieve a mechanical proposal that takes into account compatibility requirements, prying forces and bolt elongation, but preserving simplicity, an equivalent frame representing the T-stub has been lately proposed, both in non-preloaded [13] and preloaded [14] cases. These models include an effective width for stiffness calculation based on plate finite element parametric studies.…”