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METMAT - Development of Microstructured Materials

Obiettivo

Metamaterials are a wide class of artificial materials whose microstructure, at different length scale, is engineered in order to exhibit properties that cannot be found in nature, and that are capable to fulfil contrasting requirements. The aim of the project is to develop theoretical and numerical model capable to describe the behaviour of materials across multiple scale length. Samples of components with lattice microstructure will be manufactured and tested for model validation.

Attività nel progetto CIRA

The project is entirely developed at CIRA. Below a brief description of the project content:

Theory and models

  • Advanced multiscale models for lattice materials. Artificial cellular and lattice materials mimic natural materials and can be easily manufactured from a variety of solid materials. These materials have numerous applications because of their lightweight combined with high specific strength, and for their energy absorbing capability. A straightforward approach that would require the modelling of every lattice element is not practical since it would lead to extremely large models. An alternative approach is to use a multiscale method. Within this framework, the macroscopic strain field is used to generate the boundary conditions for a finite element model of a representative volume element of the lattice; at the microscopic level, the cell walls are modelled with discrete elements, such as beams or shells, and the internal forces of these elements are homogenised to produce the macroscopic stress. This approach takes into account non-linear phenomena occurring at the micro scale, such as the buckling or the plastic yielding of the cell walls, and permit to accurately model complex components without the need of very large detailed models.

  • Multiscale Dynamics. An interesting application of foams and lattices materials is in blast and impact protection, thanks to their lightweight and natural progressive crushing capability. The dynamic equilibrium equations for this materials show that two different inertia terms appear, one is related to the micro-inertia of the cell walls, the other refers to the macro-inertia of the material as a whole. The presence of these separate inertia contributions is accounted responsible for the high sensitivity of the lattices to different impact speeds. Nevertheless, this mechanism has not been clearly understood yet, and adequate modelling tools are not yet available. Within the project, the approach developed for static cases will be expanded for the modelling of the dynamic of the transients in cellular materials, by including the inertial effects, and these models will be validated by means of experimental tests.

Prototypes, experimental tests and model validation

Experimental tests will be executed on prototypes for the purpose of model validation.

Programma

PRORA

  • data inizio: Wednesday, September 16, 2015
  • durata: 36.00
Friday, September 16, 2016
95
Wednesday, February 8, 2017
METMAT
Structures and Materials
The project Microstructured materials/Metamaterials aims at developing the theoretical and numerical tools for the modelling of the mechanical properties of materials with a defined, architecture microstructure.
Structural Analysis and Design, Metallic Materials & basic processes
Advanced Materials and Processes

 

 

METMAT - Development of Microstructured Materials<img alt="" src="http://webtest.cira.it/PublishingImages/METMAT_test_articles.jpg" style="BORDER:0px solid;" />https://www.cira.it/en/space/accesso-allo-spazio-satelliti-ed-esplorazione/metmat/METMAT - Development of Microstructured MaterialsMETMAT - Development of Microstructured Materials<p>Metamaterials are a wide class of artificial materials whose microstructure, at different length scale, is engineered in order to exhibit properties that cannot be found in nature, and that are capable to fulfil contrasting requirements. The aim of the project is to develop theoretical and numerical model capable to describe the behaviour of materials across multiple scale length. Samples of components with lattice microstructure will be manufactured and tested for model validation.</p><p>PRORA</p><p style="text-align:justify;">The project is entirely developed at CIRA. Below a brief description of the project content:</p><p style="text-align:justify;"><span lang="EN-GB"><strong>Theory and models</strong></span></p><ul style="text-align:justify;"><li><p><span lang="EN-GB">Advanced multiscale models for lattice materials</span>. Artificial cellular and lattice materials mimic natural materials and can be easily manufactured from a variety of solid materials. These materials have numerous applications because of their lightweight combined with high specific strength, and for their energy absorbing capability. A straightforward approach that would require the modelling of every lattice element is not practical since it would lead to extremely large models. An alternative approach is to use a multiscale method. Within this framework, the macroscopic strain field is used to generate the boundary conditions for a finite element model of a representative volume element of the lattice; at the microscopic level, the cell walls are modelled with discrete elements, such as beams or shells, and the internal forces of these elements are homogenised to produce the macroscopic stress. This approach takes into account non-linear phenomena occurring at the micro scale, such as the buckling or the plastic yielding of the cell walls, and permit to accurately model complex components without the need of very large detailed models.</p></li><li><p><span lang="EN-GB">Multiscale Dynamics.</span> An interesting application of foams and lattices materials is in blast and impact protection, thanks to their lightweight and natural progressive crushing capability. The dynamic equilibrium equations for this materials show that two different inertia terms appear, one is related to the micro-inertia of the cell walls, the other refers to the macro-inertia of the material as a whole. The presence of these separate inertia contributions is accounted responsible for the high sensitivity of the lattices to different impact speeds. Nevertheless, this mechanism has not been clearly understood yet, and adequate modelling tools are not yet available. Within the project, the approach developed for static cases will be expanded for the modelling of the dynamic of the transients in cellular materials, by including the inertial effects, and these models will be validated by means of experimental tests.</p></li></ul><p style="text-align:justify;"><span lang="EN-GB"><strong>Prototypes, experimental tests and model validation</strong></span></p><p style="text-align:justify;">Experimental tests will be executed on prototypes for the purpose of model validation.</p>2015-09-15T22:00:00Z36.0000000000000

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 Activities

 

 

Non Linear Constitutive models for lattice materials<img alt="" src="http://webtest.cira.it/PublishingImages/multiscale_scheme_b.jpg" style="BORDER:0px solid;" />https://www.cira.it/en/space/accesso-allo-spazio-satelliti-ed-esplorazione/metmat/non-linear-constitutive-models-for-lattice-materials/Non Linear Constitutive models for lattice materialsNon Linear Constitutive models for lattice materialsThis study presents a numerical homogenization approach for the derivation of the constitutive model for lattice materials