A domain decomposition approach for coupled modelling of nonlinear soilstructure interaction
This paper proposes a new approach for modelling coupled nonlinear soilstructure interaction problems by domain decomposition. It is assumed that the soilstructure coupled system is physically partitioned into independently modelled soil and structure sub-domains. A coupling procedure based on the sequential iterative DirichletNeumann coupling algorithm is presented, which utilizes the condensed tangent stiffness matrices at the soilstructure interface to ensure and accelerate convergence to compatibility in successive update of the boundary conditions. As a special case of the proposed approach, the condensed tangent stiffness matrix is approximated via reduced order models of the partitioned sub-domains throughout the coupling iterations. A simulation environment has been developed, utilizing discipline-oriented solvers for nonlinear structural and geotechnical analysis, and is discussed. This tool is used to demonstrate the applicability of the presented coupling algorithm in modelling nonlinear soilstructure interaction problems, highlighting its relative merits compared to interface relaxation algorithms. Furthermore, the developed tool is employed for a case study involving nonlinear soilstructure interaction analysis between a plane frame and soil subjected to ground excavation, where the computational and modelling benefits of the proposed approach and the developed tool are clearly established.
domain decomposition nonlinear soilstructure interaction condensed tangent stiffness matrix reduced order model interface relaxation iterative coupling