Experimental evaluation of 3D steel joint with loading in both axis

The current European standard of steel structures (Eurocode 3), establishes the necessity of taking into account the rigidity and resistance of joints in the overall calculation of the structure. This normative uses the method of the components for obtaining the elastic characteristics of the joints, as rigidity and resistance. In the case of 3D joints, the problem of determining the components comportment, is more complex, because the comportment of the components of the joint in one of the axis is influenced by the loads in the other one. The level of stress in the minor axis influences the rigidity of the major axis, and vice versa. In the present work, two tests of an external 3D joint with additional plates in the weak axis is conducted. In the first one the major axis is loaded while the minor axis remains unloaded. In the second test, the minor axis is loaded and the load in the major axis is applied while the minor axis remains loaded, and then, the influence of the weak axis loading in the major axis stiffness is evaluated. Along this loading process, measurements of displacement sensors and load cells are carried out. In this work, the tests are conducted in the elastic range, in order to determine the global elastic stiffness of the strong axis. The moment-displacement curves for the major axis are shown, and the values of global initial stiffness in both tests are compared. These results of the tests will be used in future works for calibrating the FEM model of the joint. This work will allow a parametric analysis with the aim of characterizing the different parameters that influence the interaction between major and minor axis in the 3D joints.