General component based cruciform finite elements to model 2D steel joints with beams of equal and different depths

Abstract

This paper deals with the formulation of cruciform finite elements that model 2D steel joints for frame analysis. Three different cases are contemplated: single rectangular panels suitable for internal joints with beams of equal depth at both sides; trapezoidal panels for joints with beams of different depths at both sides and inclined stiffeners; and double rectangular panels for the case of joints with beams of different depths at both sides and with or without horizontal stiffeners in the panel zone.The cruciform elements have 4 nodes with 3 degrees of freedom per node, and take into consideration, in a consistent and complete way, the stiffness properties (components in Eurocode), including those of the panel zone. The proposed elements allow modelling simple, rigid and semi-rigid connections. In addition, they take into account all the internal forces that coincide at the joint, and the eccentricities of the internal forces coming from the beams and columns that meet at the joint. Numerical examples are solved that compare the proposed approach with complete finite element models of sample frames. The results validate the approach and demonstrate its advantages.