FEM and Multi-physic modeling and simulation of nanoporous structured SMP

In previous research activities, the nanoporous structure SMP has been investigated showing the SMP behavior, the deformation induced by water extraction or mechanical pressure and other action, the recovery action, nanomechanical experimentation, and relate the mechanical deformation state with optical behavior. In studying these nanoporous materials, validated optical, mechanical FEM and Multiphysics models should be a very useful tool for understand the behavior of the SMP photonic crystal. The research activity proposal is focused on knowledge, methods and tools development for nanoporous structures SMP modeling, simulation of mechanical and optical phenomena and behavior. The aim is to formulate a consistent, accurate and reliable framework for numerical prediction of multi-physic (coupled mechanical and optical) behavior of nanoporous SMP structures. These results will be achieved studying and developing a very effective example of multi-physics device and material: a photonic crystal Nanoporous Shape Memory Polymer (SMP). This choice has been made in order to take into account the mechanical state transitions of the SMP and its consequences on optical performances and properties of the photonic crystal. There are two main research challenges: oThe first challenge is to consider the complexity of nanoporous structure SMP in geometry, mechanical behavior and material properties. As already stated, nonlinearities, elastic instability and nanoscale effects contribute to increase the complexity. oThe second challenge refers to the development of a multi-physics (mechanical and optical) model and simulation of nanoporous SMP because of the novelty of this material. The objective of the research project is the mathematical representation of the mechanical and optical properties of the nanoporous crystal photonic SMP. The objective can be acquired by: - Development of a parametric and accurate geometrical models of native nanoporous structure; - Mechanical modelling of nanoporous crystal photonic SMP via FEA in order to obtain stress/strain status for three different situations (undeformed-native, deformed and recovered) managing structural non linearity in dependence of external loads, constrains, pore size and spatial distribution, material properties and residual stress/strain; - Development of optical models of the nanoporous photonic crystal SMP at the different states and predict the optical behaviors via geometrical optics simulation. - Coupling the mechanical state (deformation, stress-strain, nanoporous collapse etc.) with the optical properties (mainly reflection index) via multi physics modeling/simulation and different approaches (FEA modeling and geometrical optics) and data fusion. - Validation by experiments of the simulations performed on each model (mechanical, optical and multi-physic)