“…This T-junction introduces a total of six elastic elements at the joint level, three of them behaving as linear springs (represented by the letter k) and noted with the sub index ux, uy, and uz corresponding to (u) displacement and (x, y, z) the axial directions and another three corresponding to (r) rotations along the (x, y, z) axial directions. This approach was also used by [19], in which multiple simulations utilizing the most common profiles found in buses and coaches upper structures were performed, followed by a statistical analysis in order to obtain regression models for the calculation of the stiffness values for the alternative T-junctions, based on the profile dimensions (E1, E2, E3, g1, and g2). They utilized a Bayesian Kriging regression model that provided satisfactory results, however, the regression equations obtained were notably complicated having, in some cases, more than 33 terms per equation, making them impractical for everyday use in the wide industry.…”