Accurate Thermo-Elastic Numerical Analysis of Materials for Spacecraft Applications
Spacecraft structures and in particular payload elements such as telescope mirrors, antenna reflectors and optical benches, have to be designed to verify very stringent tolerance, alignment and thermo-elastic stability requirements. Performing very accurate thermo-elastic numerical analysis using finite elements is quite problematic in these cases, where the specific characteristics of materials are not sufficiently known a priori. Not only is it difficult to model the materials (ceramics, ceramic composites, carbon composites, carbon based open cell foams etc) but often the material properties are difficult to derive by test, e.g. the CTE at cryogenic temperatures. To improve the situation it is clearly needed to consider the micro-mechanical behaviour of the materials, both for the numerical derivation of material properties and to allow for the creation of representative macro-scale finite element models.
Objectives of the Research
The aim is to derive properties and provide mechanical modelling techniques for a range of similar materials that are used in space applications (ceramics, ceramic composites, carbon composites, carbon based open cell foams). The research will then investigate how properties derived from micro-scale modelling can be usefully fed into the macro-scale thermo-elastic FE analysis of a larger structure such as an antenna reflector or telescope mirror. Special attention will be paid to the thermal and mechanical behaviour of the materials, including thermal conductivity, thermo-elastic stability, elastic behaviour (meaning anisotropy, homogeneity, linearity), as well as the failure modes and stress-strain relations.
In summary, the objectives of the project are:
- Characterise materials microstructure using imaging techniques.
- Conversion of the microstructure into detailed finite element models.
- Generation of macro-scale models taking into account the micro-structure.
- Correlation with samples and analysis of benchmark cases.
Dr Lee Margetts, Senior HPC Consultant, University of Manchester
Dr Paul Mummery, Senior Lecturer, School of Materials Science
Mr Vendel Szeremi, Postgraduate Researcher, School of Materials Science
Joint European Space Agency/UoM funded project: August 2007 - September 2009
Please contact Lee Margetts for further details.