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FAILURE ANALYSIS - ERROR ESTIMATION FOR MULTISCALE METHODS

FAILURE ANALYSIS - ERROR ESTIMATION FOR MULTISCALE METHODS

Leitung:  P. Wriggers
Team:  N. Hajibeik
Jahr:  2009
Ist abgeschlossen:  ja

This project is concerned with the development of tools for error-estimation based adaptive multiscale failure analysis.  In order to enable a more accurate mechanical analysis of composite aircraft substructures, existing discretisation error estimators will be improved to be used as indicators for mesh refinement.  Additionally. physical error estimators will be developed to identify regions where higher-order material modelling is required. Explicit mesoscale material information will be incorporated at these regions using multiscale methods to complement the macroscopic material model for the
composite.

The application of the current work is mainly in analyzing heterogeneous materials and especially composites. The focused example is a composite plate with a hole consists of different layers with aligned longitudinal phases embedded in the matrix. Each layer has a different phase direction and the layers are placed symmetrical (0°/ 45°/ -45°/ 90°)s. Therefore the used RVE for the homogenization purpose consists of 8 layers, in which layers of 0° and 90° consist of exact 8 phases and the layers with diagonal phases (45° and -45°) have 9 phases in different lengths as explained later in 5.2.

For the main simulation of the plate the computation is reduced due to the symmetry of the composite structure and the plate geometry. The boundary conditions will be adjusted for that matter. The adaption algorithm is followed in three-dimensional simulations. The discretization error estimation is done two times to get accurate numerical response that can be used to compute the modelling error. The microstructure is inserted in the marked region shown in the right picture.

 

This project is funded under the European Seventh Framework Programme.  The task comprises a subproject under the large-scale research initiation Maaximus (More Affordable Aircraft Structure Lifecycle through Extended, Integrated and
Mature Numerical Sizing) headed by the Airbus  company.