ACOSTA - Advanced Concepts for Structure Analysis of Large Lightweight Structures

The ACOSTA project intended to develop new tools for the numerical analysis and reliability analysis of large launcher structures. Its main work packages comprised: Domain decomposition/branching analysis, reliability and sensitivity, new shell elements.

Short Description

While the tools were developed and tested on the basis of finite element models of the ARIANE 5 Front Skirt, it may be safe to assume that the results will be applicable for a wide range of problems in aerospace engineering.

The company INTALES together with the participating institutes of the University of Innsbruck has acquired expert knowledge in these tasks and is on the way to the scientific leading position in aerospace engineering in this area. Domain decomposition/branching analysis: Due to the splitting of numerical tasks in computing the behavior of the ARIANE 5 launcher among European participants, understanding domain decomposition is a must.

Domain decomposition was success- fully used as a pre-conditioner in iterative solvers. In the project, both domain decomposition and branching analysis were implemented into software codes, parallelized and tested in the branching analysis of buckling behavior.

Reliability and sensitivity: The approach of the project was that understanding reliability (e.g. to avoid buckling failure) can only be achieved on the basis of sensitivity analysis. For this purpose, a toolbox of sampling based methods was developed and successfully applied in the launcher as well as the engine nozzle in associated GSTP and FLPP projects.

Sensitivity analysis tools range from Monte Carlo estimates of correlation measures input/output, resampling schemes for assessing their significance, ranking the input variables according to influence, tolerance intervals, random field models of material parameters, to acceleration of convergence of sampling based methods in iterative solvers. All these numerical tools have been implemented into independent software solutions.

Shell elements: Based on the need for modeling shells, intersections and stringers, improving the available shell elements has become a necessity. This also applies to the case of an improved branching analysis that requires the exact determination of bifurcation points. For this purpose, new solid shell elements were developed and successfully tested by means of standard and extended benchmark studies as well as the front skirt models.

Project Partners


INTALES GmbH Engineering Solutions - Hermann-Josef Starmans


  • University of Innsbruck, Department of Mathematics - Prof. Alexander Ostermann
  • University of Innsbruck, Unit for Engineering Mathematics - Prof. Michael Oberguggenberger

Contact Address

INTALES GmbH Engineering Solutions
Hermann-Josef Starmans
Innsbrucker Straße 1
A-6161 Natters
Tel.: +43 (512) 546 111