The article is devoted to the study of flange beam to column connections to analyze their nonlinear behavior. In the course of the study, a simplified analytical model was created using the method of variable elasticity parameters to determine the stress-strain state of these connections. The proposed mechanical model makes it possible to predict the strength, stiffness, ductility of joints, as well as possible types of fracture and deformation mechanisms of the bent elements of flange joints. This model can be useful for engineers and specialists in the field of design and analysis of civil structures. The proposed refined component model is an analogue of the Eurocode 3 model. The paper presents a numerical experiment on modeling the junction of a beam with a column by the finite element method. A comparative analysis of the results obtained with the results of tests of flange connections of steel building structures performed by the University of Sydney (USYD) is presented.

Keywords: flange connections, flange plate, stress-strain state, method of variable elasticity parameters, component method, refined component model, finite element method, elastic-plastic state, plastic hinge, modified stiffness, bending model of flange plate