Skip to main content
European Commission logo print header

Non-linear static multiscale analysis of large aero-structures

Final Report Summary - MUSCA (Non-linear static multiscale analysis of large aero-structures)

The main innovation in the MUSCA was to address built-up structures with a high degree of complexity where the modelling is fine enough to capture local effects or non-linear behaviour that are necessary to predict both failure initiation and collapse. The scientific tools to reach these objectives require novel advances in computational mechanics and statistics that are addressed in MUSCA in parallel with large scale computing. Based on the state of the art, the consortium identified three key research areas to address:
- Techniques for large scale Non Linear analysis: domain decomposition techniques coupled with advanced parallel processing Non Linear solvers, error estimator for quality assessment
- Multi-criteria failure analysis: critical review, selection and validation of the most efficient engineering procedures for multi-mode failure analysis of structural details
- Sensitivity and reliability techniques: assessment of input uncertainties (material properties, geometry and load scattering) on the structural performance using stochastic simulations, sensitivity surface response methods.

The project was structured into the following work packages (WP):

WP1 - analysis of structural certification of large components
Four large component structural tests were identified and documented by the industrial partners, with a special focus on the following items:
- description of the role of the test with regards to the overall process
- description of the main analysis difficulties
- process analysis, with a recommended way towards a more 'simulation assisted' process
- delivery of CAD, FEM to the partners

WP2 - Large modelling capabilities
The main objective of WP2 was to develop methods and computational schemes of such effectiveness that displacements, stresses and the maximum load carrying capacity of structural components of a size up to large aircraft sections can be accurately analysed with control of the error in the numerical solutions.

WP3 - Smart multi-criteria failure analysis
Within WP3 the multi-mode failure behaviour of large structures were planned to be identified and structural details would be designed for each generic analysis difficulty of existent test data. Existing failure criteria would be reviewed or further developed and validated using the defined structural details to provide an integrated multi-criteria failure analysis that could be accepted by airworthiness authorities.

WP4 - Reliability & sensitivity methods
The objective of WP4 was to deliver numerical tools that would be able to predict the effect of uncertainties on component performance and validate the integration of various types of data necessary to generate an understanding of a given component's characteristics including the uncertainties in materials, loading in a probabilistic sense.

The three major research topics identified above will constitute the core R&D activity of MUSCA, but special attention will be made to focus partnership activities on actual analysis needs. The MUSCA consortium has therefore adopted the following work strategy:
a) WP1 analysed the certification process for some representative large aircraft components. These have been provided by industrial partners in order to demonstrate how testing and analysis are currently used to provide structural certification. Main analysis difficulties have been identified and classified for those MUSCA industrial large component benchmarks (WP1). Costs and duration have been evaluated to establish a baseline for future gains.
b) Numerical benchmark cases with associated existing structural tests have then been identified representing main analysis problems derived from large-scale industrial benchmarks (WP2.0 WP3.0 and WP4.0). The partnership activities have been exclusively focused on these numerical test cases for evaluation and development of methodologies in each of the three key research areas previously defined.
c) Based on the most promising methodologies available, the actual validation of the overall multi-scale analysis process were planned to be made on three selected industrial benchmarks (WP5), with an original collaborative work organisation between partners. The validation of MUSCA developments were planned to be made using existing experimental test data provided by industrial partners for large-scale benchmark tests.
d) Potential cost savings and cycle reduction were planned to be assessed compared to base line established in WP1. Finally, with the experience gained in WP5, recommendations would be provided for an evolution of the structure justification process (WP6) that integrates the methodologies developed in MUSCA. To reach this goal, a senior expert in airworthiness requirements was associated with MUSCA in WP1 and WP6, in order to obtain information and advice on issues like analysis methods, processes, quality control and associated responsibilities.