Projects / Programmes
Development of multifunctional auxetic cellular structures
| Code |
Science |
Field |
Subfield |
| 2.11.02 |
Engineering sciences and technologies |
Mechanical design |
Special constructions know-how |
| Code |
Science |
Field |
| T000 |
Technological sciences |
|
| Code |
Science |
Field |
| 2.03 |
Engineering and Technology |
Mechanical engineering |
auxetic cellular material, mechanical charaterization, experimental testing, computational
simulations,optimized structure, graded porosity
Researchers (14)
Organisations (2)
Abstract
The auxetic cellular structures are a novel type of cellular metamaterials which exhibit extraordinary mechanical properties, which cannot be achieved by any other conventional material. Their recent breakthrough is associated with advances in additive manufacturing technologies which allow fabrication of structures with complex internal geometry. The geometry of auxetic metamaterials (morphology and topology) and mechanical behaviour are not yet well characterised and many influencing parameters have yet to be determined, especially when auxetic structures are subjected to dynamic loading conditions. The purpose of the proposed research is the development of new, topologically optimised three-dimensional auxetic structures with uniform and graded cellular structure with follow-on comprehensive experimental and computational characterisation of their mechanical behaviour under various loading conditions, including consideration of large strains, strain rate sensitivity and fatigue. An extensive experimental testing programme of newly developed auxetic specimens will be complemented by the advanced finite element modelling and computer simulations. The experimental testing will be supported by a non-destructive infrared thermography technique enabling excellent visualization and consequent analysis of local deformation process. This will provide necessary information to better understand the complex deformation mechanism of three-dimensional auxetic structures when subjected to various mechanical loading conditions. In combination with parametric computational simulations, homogenisation and topological optimisation procedures, the results of this research will provide means to identify the most appropriate geometrical and material parameters of auxetic structures and consequently to develop state-of-the-art significant knowledge for efficient application of auxetic materials in future engineering applications.
Significance for science
The research group has over 15 years of experience in analysis and development of cellular materials through geometrical characterisation, computational simulations and experimental testing. It is the only group in Slovenia perusing the development and application of cellular materials in engineering applications. It has established an excellent multi-international collaboration with several partner institutions abroad. The group has published research results in many original scientific papers in the highest-ranking journals (A'' and A' rating) and disseminated their knowledge at numerous scientific and professional conferences all over the world. New research methods and applicative results were already successfully transferred to several companies (KreAl, Talum, Kidričevo in Slovenia and MJ Amaral in Portugal).
The proposed project will extensively contribute to progress of engineering science in development and characterization of novel auxetic cellular structures and their computational modelling. This will significantly enhance the application possibilities of auxetic cellular structures in general engineering, which was so far also not possible due to lack of understanding and required manufacturing techniques for their fabrivation. However, the new breakthroughs in additive manufacturing technologies now enable fabrication of this new class of materials with extraordinary properties and consequent detailed characterization of their mechanical properties not possible before.
The results of the proposed project will significantly contribute to the development of innovative auxetic metamaterials with internal graded cellular structure, which will be fully characterised with appropriate experimental testing programme of real samples, supplemented by parametric computational simulations. The developed models will provide for more accurate predictions of the behaviour of uniform and graded auxetic cellular structures under uni- and multi-axial loading conditions.
Additionally, the efficient computational models and extracted homogenised constitutive laws will require less processing time of simulation models, providing higher reliability of the results and lower computational effort (short computational time) which makes them very attractive for use in general engineering and assures a wide range of possible application for any industrial needs.
It is envisaged that the results of the proposed research will be published in high-ranking reviewed international scientific journals in the fields of engineering design, materials science and mechanics and disseminated and presented to the scientific community at several international scientific conferences.
Significance for the country
The cellular materials have been successfully incorporated in many industrial applications to realise new light-weight and competitive products.
Results of the proposed project are directly applicable in contemporary industry, since the proposed experimental testing programme supplemented by computational modelling and simulation will allow for subsequent optimisation and development of novel auxetic structures to define the most suitable design parameters for a given application. Extensive parametric analyses will also contribute to development of new design guidelines of light-weight auxetic cellular structures making them more attractive in engineering society. This will be further supported by adaptable fabrication of complex auxetic structures by layer additive technologies. The unique auxetic deformation behaviour, low density, enhanced abrasion and energy absorption properties, higher indentation/penetration and shear resistance, fracture toughness and biocompatible base materials will make them perfect for use in automotive, aerospace, warfare, textile and biomedical engineering industry as bomb resistant curtains, composite materials, helmets, body armours, seat belts, dental flosses, seat cushions, easy-to clean filters, drug-release bandages, knee and elbow pads, packing materials, implants etc. Such wide application possibilities will definitely represent huge possibilities for small to large Slovenian companies (there has already been a request from a Slovenian company for development of a sandwich panel with auxetic core) or enterprises and its placement on the market where there is still a lack of materials/products exhibiting the auxetic behaviour with numerous advantages in comparison to conventional materials. Furthermore, due to lower mass needed for fabrication of light-weight auxetic structures with improved mechanical behaviour, there is also a lower impact to the environment during its fabrication and the possibility for easy recycling after their use.
A design patent of newly developed 3D auxetic structures is also envisaged.
Most important scientific results
Interim report,
final report
Most important socioeconomically and culturally relevant results
Interim report,
final report
