Abstract:
This paper presents a detailed three-dimensional methodology for analyzing the nonlinear moment-rotation behavior of bolted steel connections using the Finite Element method to provide a reliable analytical tool that can supplement limited experimental data. The approach uses the ABAQUS software to conduct a nonlinear displacement-based FE analysis with 3D continuum elements, specifically eight-node brick (C3D8I) and six-node wedge (C3D6) elements. A key feature of the simulation is the explicit modeling of contact and potential slip between all connection components—such as plates, angles, bolts, and washers—using a master-slave contact algorithm. The FE models incorporate critical parameters like bolt pretension and a friction coefficient, and they use a trilinear stress-strain material model for steel derived from experimental coupon tests. To validate the methodology, FE models of connection configurations from a previous experimental study are created, and the resulting moment-rotation curves show good agreement with the test results. Parametric FEA studies are then performed to demonstrate that variations in friction and bolt pretension can alter the connection response by up to 20%, and to show that the combined response of connection components is greater than the sum of their individual actions, highlighting the predictive power of the detailed 3D FEA approach.
