Characterization of metamaterials through advanced beam elements

The thesis work is set in development and extension of MUL2 micromechanics code, based on CUF, or well known as Carrera Unified Formulation. Carrera Unified formulation is a class of theories of Structure on which Finite Elements are formulated. Its main aim is to lighten FEM analysis computational costs and to cover a wide range of field of application. The thesis work is focused on applying CUF to metamaterials analysis, it could be divided into four main parts: 1.Training: one month-long period spent to learn about how to use MUL2 micromechanics code, namely how to create input files and to become familiar with \textit{Fortran} programming language. 2. Code Implementation: four months-long period used to create a new tool able to provide metamaterial unit cell dispersion curves and modes of vibration. 3. Benchmarking: two months-long period in order to looking for similar works in literature, able to be used as solid benchmark for understanding if the new code effectively works in the correct way. 4. Obtaining transmission curves: a month-long period where have been carried out dynamic analysis in order to capture the transmission properties of an array composed of few metamaterial cells. The utility of this kind of graph is to be compared with the dispersion curves, in order to check out the bandgap position. 5. Case study: three-month period (May, June, July) spent at California Institute of technology. In this period has been carried out further refinements to the code and it has been studied a new metamaterial, provided by the European project CASTLE, composed of a Melamine matrix with an Aluminum inclusion. Finally, a parametric analysis is carried out. The visiting period at California Institute of technology has been an outstanding growth period, that gaves the possibility to learn about a wide range of aspects related to metamaterials and to work and collaborate with subject matter experts.