000021606 001__ 21606
000021606 005__ 20170622131254.0
000021606 04107 $$aeng
000021606 046__ $$k2017-06-15
000021606 100__ $$aGruber, Fabian M.
000021606 24500 $$aTIME INTEGRATION OF DUAL CRAIG-BAMPTON REDUCED SYSTEMS

000021606 24630 $$n6.$$pComputational Methods in Structural Dynamics and Earhquake Engineering
000021606 260__ $$bNational Technical University of Athens, 2017
000021606 506__ $$arestricted
000021606 520__ $$2eng$$aIn this paper, time integration procedures are demonstrated and investigated for dual Craig-Bampton reduced systems. The dual Craig-Bampton method for the reduction and successive coupling of dynamic systems employs free interface vibration modes, attachment modes and rigid body modes to build the reduction bases of the substructures, but assembles the substructures using interface forces. Thereby, the interface kinematic conditions are transformed, allowing for incompatibilities associated with the equilibrium residual in the substructure. Hence, the eigenvalues of the reduced-order model are not guaranteed to be upper bounds for the unreduced system’s eigenvalues. Furthermore, the dual Craig-Bampton reduced system will always have as many negative eigenvalues as interface coupling conditions. The reduced system is unstable, rendering a straightforward time integration of the dual Craig-Bampton reduced system impossible. The feasibility of a reliable time integration of dual Craig-Bampton reduced systems is demonstrated and investigated in detail. The unstable behavior when time-integrating such systems without further modifications is illustrated and two approaches to overcome this instability are suggested: on the one hand, a modal analysis of the reduced system is performed as a subsequent step to the dual Craig-Bampton reduction. Only modes corresponding to positive eigenvalues are thereby kept for transient analysis. This allows for a stable time integration. On the other hand, a modal interface reduction during the dual Craig-Bampton reduction process is performed and only interface modes corresponding to positive eigenvalues are kept. This makes the final reduced system also positive definite. The accuracy using these two approaches is demonstrated in examples with either different initial conditions or varying external periodic excitations.

000021606 540__ $$aText je chráněný podle autorského zákona č. 121/2000 Sb.
000021606 653__ $$aTime Integration, Dynamic Substructuring, Component Mode Synthesis, Model Order Reduction, Dual Craig-Bampton Method.

000021606 7112_ $$aCOMPDYN 2017 - 6th International Thematic Conference$$cRhodes Island (GR)$$d2017-06-15 / 2017-06-17$$gCOMPDYN2017
000021606 720__ $$aGruber, Fabian M.$$iRixen, Daniel J.$$iGille, Max
000021606 8560_ $$ffischerc@itam.cas.cz
000021606 8564_ $$s3095466$$uhttps://invenio.itam.cas.cz/record/21606/files/17213.pdf$$yOriginal version of the author's contribution as presented on CD, section: [MS12] Advances in model reduction techniques in structural and multi-physics dynamical systems
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000021606 962__ $$r21500
000021606 980__ $$aPAPER