| Title: |
Untersuchungen zur modalen Superposition für die a priori Detektion versagenskritischer Regionen dynamisch beanspruchter Strukturen ; Investigations on mode superposition techniques for the a priori detection of failure-critical regions of dynamically loaded structures |
| Authors: |
Strzalka, Carsten |
| Contributors: |
Zehn, Manfred; Technische Universität Berlin; Hühne, Christian |
| Publication Year: |
2023 |
| Collection: |
TU Berlin: Deposit Once |
| Subject Terms: |
600 Technik; Medizin; angewandte Wissenschaften::620 Ingenieurwissenschaften::620 Ingenieurwissenschaften und zugeordnete Tätigkeiten; structural dynamics; modal analysis; modal stress; finite-element-method; fatigue analysis; Strukturdynamik; Modalanalyse; modale Beanspruchung; dynamische Auslegung; Lebensdaueranalyse |
| Description: |
The reliable design of structures and components under dynamic loading is increasingly becoming the focus of daily industrial application. The often thin-walled structures of modern lightweight design, resulting from optimisation processes, tend to be more sensitive to dynamic stress and failure. As the fatigue failure of dynamically loaded structures is mostly a localised phenomenon, the structural regions relevant for detailed stress analysis and experimental validation are often unknown in advance and need to be estimated by expensive numerical investigations. Great potential for reducing the numerical effort emerges, if the classical strength verification process is extended not to the evaluation of whether a structure can withstand the applied loading but to the evaluation of which structural regions require a more detailed consideration and if these statements can be made qualitatively, but in advance, i.e., a priori. The a priori identification of these structural areas thus represents the main objective of the present work. The basis of the presented investigations is the approximation of the dynamic stress state of discretised structures using mode superposition techniques. As fundamental dynamic properties, the elastic eigenmodes of a structure are determined in the early stages of product development. Based on the modal stress derived from the system’s eigenvectors and the frequency domain solution of the equations of motion in modal space, the present work documents comprehensive investigations on the approximation of the modal contributions to dynamic stress fields. By detailed consideration of the influences of load configuration and frequency content as well as the normalisation of eigenvectors and modal stress quantities, weighting coefficients for the a priori superposition of modal stress fields are developed for force- and base-excited systems. Parameters from classical fatigue analysis are applied for automated detection of failure-critical structural regions. Validation is performed on ... |
| Document Type: |
doctoral or postdoctoral thesis |
| File Description: |
application/pdf |
| Language: |
German |
| DOI: |
10.14279/depositonce-17539 |
| Availability: |
https://depositonce.tu-berlin.de/handle/11303/18734; https://doi.org/10.14279/depositonce-17539 |
| Rights: |
https://creativecommons.org/licenses/by/4.0/ |
| Accession Number: |
edsbas.2E7BC310 |
| Database: |
BASE |