Rapid structural design change evaluation with an experiment based FEM

Research output: Contribution to journalArticle

7 Citations (Scopus)

Abstract

The work in this paper proposes a dynamic structural design model that can be developed in a rapid fashion. The approach endeavours to produce a simplified FEM developed in conjunction with an experimental modal database. The FEM is formulated directly from the geometry and connectivity used in an experimental modal test using beam/frame elements. The model sacrifices fine detail for a rapid development time. The FEM is updated at the element level so the dynamic response replicates the experimental results closely. The physical attributes of the model are retained, making it well suited to evaluate the effect of potential design changes. The capabilities are evaluated in a series of computational and laboratory tests. First, a study is performed with a simulated cantilever beam with a variable mass and stiffness distribution. The modal characteristics serve as the updating target with random noise added to simulate experimental uncertainty. A uniformly distributed FEM is developed and updated. The results show excellent results, all natural frequencies are within 0.001% with MAC values above 0.99. Next, the method is applied to predict the dynamic changes of a hardware portal frame structure for a radical design change. Natural frequency predictions from the original FEM differ by as much as almost 18% with reasonable MAC values. The results predicted from the updated model produce excellent results when compared to the actual hardware changes, the first five modal natural frequency difference is around 5% and the corresponding mode shapes producing MAC values above 0.98.

Original languageEnglish (US)
Pages (from-to)335-353
Number of pages19
JournalJournal of Sound and Vibration
Volume211
Issue number3
StatePublished - Apr 2 1998

Fingerprint

structural design
Structural design
resonant frequencies
Finite element method
evaluation
Natural frequencies
hardware
Experiments
cantilever beams
modal response
Hardware
random noise
dynamic response
mass distribution
Cantilever beams
stiffness
Model structures
Dynamic response
Stiffness
geometry

All Science Journal Classification (ASJC) codes

  • Condensed Matter Physics
  • Mechanics of Materials
  • Acoustics and Ultrasonics
  • Mechanical Engineering

Cite this

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title = "Rapid structural design change evaluation with an experiment based FEM",
abstract = "The work in this paper proposes a dynamic structural design model that can be developed in a rapid fashion. The approach endeavours to produce a simplified FEM developed in conjunction with an experimental modal database. The FEM is formulated directly from the geometry and connectivity used in an experimental modal test using beam/frame elements. The model sacrifices fine detail for a rapid development time. The FEM is updated at the element level so the dynamic response replicates the experimental results closely. The physical attributes of the model are retained, making it well suited to evaluate the effect of potential design changes. The capabilities are evaluated in a series of computational and laboratory tests. First, a study is performed with a simulated cantilever beam with a variable mass and stiffness distribution. The modal characteristics serve as the updating target with random noise added to simulate experimental uncertainty. A uniformly distributed FEM is developed and updated. The results show excellent results, all natural frequencies are within 0.001{\%} with MAC values above 0.99. Next, the method is applied to predict the dynamic changes of a hardware portal frame structure for a radical design change. Natural frequency predictions from the original FEM differ by as much as almost 18{\%} with reasonable MAC values. The results predicted from the updated model produce excellent results when compared to the actual hardware changes, the first five modal natural frequency difference is around 5{\%} and the corresponding mode shapes producing MAC values above 0.98.",
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Rapid structural design change evaluation with an experiment based FEM. / Chu, C. H.; Trethewey, M. W.

In: Journal of Sound and Vibration, Vol. 211, No. 3, 02.04.1998, p. 335-353.

Research output: Contribution to journalArticle

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