Efficient simulation of flexible body systems with frictional contact/impact

This thesis mainly contributes to three areas in the field of multibody dynamics simulation (MBS): (i) numerical integration methods, (ii) modeling of flexible bodies that undergo large rotation and large deformation, and (iii) modeling of frictional contact/impact between flexible bodies. Specifically, six different implicit low order numerical integration methods to solve the differential algebraic equations (DAEs) are discussed herein and their performance is compared based on various metrics such as order of convergence, energy preservation, constraint satisfaction, and efficiency.;In this thesis, the Absolute Nodal Coordinate Formulation (ANCF) is thoroughly explored to model the geometrically nonlinear elastic bodies in the flexible multibody systems. To avoid the locking problems of original ANCF, gradient deficient ANCF is used in index-3 DAE framework for thin beam applications. The formulation of gradient deficient ANCF beam element for straight as well as initially curved beam is investigated. Several numerical experiments are performed to study the convergence behavior of gradient deficient ANCF and to validate the results.;Moreover, two widely used approaches for handling frictional contact of rigid bodies, namely the penalty method and the Differential Variational Inequality (DVI) method, are extended to solve the frictional contact/impact problem of ANCF flexible bodies. This thesis focuses on developing, implementing, and validating these contact modeling approaches within the ANCF framework.;In the first approach, the penalty-based Hertzian contact model and regularized Coulomb friction model is used to model contact/impact between ANCF beams. A novel approach of the spherical decomposition of beams is introduced, which simplifies the beam contact detection problem. The beam-to-beam and beam-to-rigid contact/impact cases are considered in the numerical experiments. The results are validated using the commercial software, ABAQUS and the research software, FEAP.;In the second approach, the traditional DVI method is extended to model frictional contact/impact between ANCF beams. A detailed derivation of this approach for both frictionless and frictional contact/impact is provided along with implementation details. The complementarity condition in the traditional DVI method is only valid for purely inelastic impact. A new complementarity condition is introduced, which includes the coefficient of restitution to model a generalized impact problem. The numerical experiments confirm that total energy of the system is conserved for the frictionless impact case due to introduction of new complementarily condition. Moreover, the results of DVI approach are compared with those obtained using the penalty approach for the beam-to-beam and beam-to-rigid contact/impact cases.;Finally, the capabilities of ANCF beams are demonstrated through the simulation of complex flexible multibody systems. The models considered for demonstration purpose include a satellite model with self deployable solar panels and an elevator traveling cable model.