Substructure Modeling and Interface Characterization of Lap-Joint Beam

The purpose of this work is to model the interface behavior of a bolted lap joint with dynamic substructuring techniques. Assembled structures are notable for their nonlinearities, energy dissipation, and uncertainties due to sliding and slapping of the substructures at the joint interface. The consequential linear and nonlinear effects make it imperative to accurately model the complex joint interface physics. A dual-assembly method is used to couple linear beam substructures and a nonlinear interface subdomain with Lagrange multipliers. Coupling methodologies that employ Lagrange multipliers allow the solvers to be tuned to the physics of each domain and subsequently increase the efficiency of the solution. Furthermore, this methodology enables the implementation of various joint models. The linear joint model employed in this work simulates the joint dynamics with springs and dampers, which are inserted between coincident nodes of the substructures. These elements inhibit the interface degrees of freedom from rigid coupling and define the contact stiffness and contact damping.