Dual Craig-Bampton component mode synthesis method for model order reduction of nonclassically damped linear systems

• Published in: Mechanical systems and signal processing 2018-10, Vol.111, p.678-698
• Main Authors: Gruber, Fabian M., Rixen, Daniel J.
• Format: Article
• Language: English
• Subjects: Complex modes; Component mode synthesis; Coupling; Dampers; Dual Craig-Bampton method; Dynamic substructuring; Equations of motion; Linear algebra; Linear systems; Micromachining; Model order reduction; Model reduction; Nonclassically damped systems; Numerical analysis; Polynomials; Rigid structures; Rigid-body dynamics; State space models; State-space formulation; Substructures; Viscous damping
• ISSN: 0888-3270; 1096-1216
• DOI: 10.1016/j.ymssp.2018.04.019

•Extension of dual Craig-Bampton method to nonclassically damped systems.•Reduced based on complex free interface normal modes.•Dual coupling procedure based on interface forces.•Substructures coupled in state-space representation.•Proper treatment of rigid body modes in assembled structural systems in state-space. The original dual Craig-Bampton method for reducing and successively coupling undamped substructured systems is extended to the case of arbitrary viscous damping. The reduction is based on the equations of motion in state-space representation and uses complex free interface normal modes, residual flexibility modes, and state-space rigid body modes. To couple the substructures in state-space representation, a dual coupling procedure based on the interface forces between adjacent substructures is used, which is novel compared to other methods commonly applying primal coupling procedures in state-space representation. The very good arbitrary viscous damping of the dual Craig-Bampton approach is demonstrated on a beam structure with localized dampers. The results are compared to a classical Craig-Bampton approach for damped systems showing the potential of the proposed method.