TY  - JOUR
A1  - Abdelnour, Mena
A1  - Zabel, Volkmar
T1  - Modal identification of structures with a dynamic behaviour characterised by global and local modes at close frequencies
JF  - Acta Mechanica
N2  - Identification of modal parameters of a space frame structure is a complex assignment due to a large number of degrees of freedom, close natural frequencies, and different vibrating mechanisms. Research has been carried out on the modal identification of rather simple truss structures. So far, less attention has been given to complex three-dimensional truss structures. This work develops a vibration-based methodology for determining modal information of three-dimensional space truss structures. The method uses a relatively complex space truss structure for its verification. Numerical modelling of the system gives modal information about the expected vibration behaviour. The identification process involves closely spaced modes that are characterised by local and global vibration mechanisms. To distinguish between local and global vibrations of the system, modal strain energies are used as an indicator. The experimental validation, which incorporated a modal analysis employing the stochastic subspace identification method, has confirmed that considering relatively high model orders is required to identify specific mode shapes. Especially in the case of the determination of local deformation modes of space truss members, higher model orders have to be taken into account than in the modal identification of most other types of structures.
KW  - Fachwerkbau
KW  - Holzkonstruktion
KW  - Schwingung
KW  - three-dimensional truss structures
KW  - vibration-based methodology
KW  - numerical modelling
Y1  - 2023
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20230525-63822
UR  - https://link.springer.com/article/10.1007/s00707-023-03598-z
VL  - 2023
SP  - 1
EP  - 21
PB  - Springer
CY  - Wien
ER  - 
TY  - THES
A1  - Abeltshauser, Rainer
T1  - Identification and separation of physical effects of coupled systems by using defined model abstractions
N2  - The thesis investigates at the computer aided simulation process for operational vibration analysis of complex coupled systems. As part of the internal methods project “Absolute Values” of the BMW Group, the thesis deals with the analysis of the structural dynamic interactions and excitation interactions. The overarching aim of the methods project is to predict the operational vibrations of engines.
Simulations are usually used to analyze technical aspects (e. g. operational vibrations, strength, ...) of single components in the industrial development. The boundary conditions of submodels are mostly based on experiences. So the interactions with neighboring components and systems are neglected. To get physically more realistic results but still efficient simulations, this work wants to support the engineer during the preprocessing phase by useful criteria.
At first suitable abstraction levels based on the existing literature are defined to identify structural dynamic interactions and excitation interactions of coupled systems. So it is possible to separate different effects of the coupled subsystems. On this basis, criteria are derived to assess the influence of interactions between the considered systems. These criteria can be used during the preprocessing phase and help the engineer to build up efficient models with respect to the interactions with neighboring systems. The method was developed by using several models with different complexity levels. Furthermore, the method is proved for the application in the industrial environment by using the example of a current combustion engine.
T2  - Identifikation und Separation physikalischer Effekte von gekoppelten Systemen mittels definierter Modellabstraktionen
T3  - ISM-Bericht // Institut für Strukturmechanik, Bauhaus-Universität Weimar - 2017,1 
KW  - Strukturdynamik
KW  - Wechselwirkung
KW  - Schwingung
KW  - Berechnung
KW  - Numerische Berechnung
KW  - Modellbildung
KW  - Schwingungsanalyse
KW  - Simulationsprozess
Y1  - 2017
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20170314-28600
ER  -