A higher-order parametric nonlinear reduced-order model for imperfect structures using Neumann expansion

Open access
Date
2021-06Type
- Journal Article
Abstract
We present an enhanced version of the parametric nonlinear reduced-order model for shape imperfections in structural dynamics we studied in a previous work. In this model, the total displacement is split between the one due to the presence of a shape defect and the one due to the motion of the structure. This allows to expand the two fields independently using different bases. The defected geometry is described by some user-defined displacement fields which can be embedded in the strain formulation. This way, a polynomial function of both the defect field and actual displacement field provides the nonlinear internal elastic forces. The latter can be thus expressed using tensors, and owning the reduction in size of the model given by a Galerkin projection, high simulation speedups can be achieved. We show that the adopted deformation framework, exploiting Neumann expansion in the definition of the strains, leads to better accuracy as compared to the previous work. Two numerical examples of a clamped beam and a MEMS gyroscope finally demonstrate the benefits of the method in terms of speed and increased accuracy. Show more
Permanent link
https://doi.org/10.3929/ethz-b-000493359Publication status
publishedExternal links
Journal / series
Nonlinear DynamicsVolume
Pages / Article No.
Publisher
SpringerSubject
Defects; Geometric nonlinearities; Nonlinear modeling; Parametric; Reduced-order modelsOrganisational unit
03973 - Haller, George / Haller, George
02618 - Institut für Mechanische Systeme / Institute of Mechanical Systems
03973 - Haller, George / Haller, George
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