In WP1, DCs 2 & 11 worked on novel reduced-order modeling and fast optimization: DC2 worked on reduced order frameworks for fast and parametric (stochastic) analysis of (in)finite metamaterials. DC11 worked on efficient modeling for fast parametric analysis of chiral phononic crystals, incorporating viscoelastic materials, and developing a machine learning based optimization routine. Besides, DCs 1, 2, 3, 6, 8 and 9 worked on enhancing broadband and (omni)direction sound absorption and/or sound transmission loss: DC1 modeled and analyzed the potential of wire mesh gratings as sound absorbers. DC2 investigated the impact of resonator detuning on performance broadening. DC3 took first steps in the modeling of waveguides with scatterers. DC6 developed (equivalent) models and performed first experiments for sonic crystal noise barriers with Helmholtz resonators. DC8 developed fast modeling and optimization routines to simulate and optimize the sound transmission of metamaterial partitions. DC9 investigated the trade-off between acoustic performance and structural efficiency of finite sonic crystal barriers via simulation and first experiments.
In WP2, DC4 worked on improving conventional manufacturing-based metamaterial production. Besides investigating manufacturing variability in injection moulded metamaterials, DC4 investigated the redesign for injection moulding of nonlinear locally resonant metamaterials. DC5 worked on improving additive manufacturing-based metamaterial production. Focusing on selective laser sintering, DC5 investigated the correlations between dimensional variations, printer bed temperature, and the natural frequency of printed beams. DCs 2 and 10 took first steps towards the development of novel combined metamaterial manufacturing methods: DC2 developed reduced order modeling strategies to simulate the impact of geometric variability, for uncertainty propagation in novel manufacturing frameworks. DC10 took first steps in investigating the combination of a metablocker metamaterial with an acoustic black hole plate.
In WP3, DCs 9, 10, 11 researched finite structure and boundary condition effects: DC9 developed models for finite phononic crystals to assess the effect of geometric variations and performed first tests. DC10 developed (reduced) models for and studied finite structure and boundary condition effects of a metablocker acoustic metamaterial. DC11 investigated the impact of imperfect axial excitation in chiral phononic crystals. DCs 4 and 5 worked on understanding and exploiting variability and uncertainty effects in vibro-acoustic metamaterials: DC4 performed a simulation-based investigation of the performance bounds for different injection moulded production parameters on resonator level. DC5 investigated the dimensional accuracy and vibrational properties of selective laser sintered parts. DCs 7 and 9 focused on improving and extending vibro-acoustic performance metrics: DC7 set up a workflow for obtaining objective and subjective metrics, applied to micro-perforated panels, and performed initial validations.
In WP4, 3 industrially relevant demonstrator projects have been defined. All 3 projects have started, and for 2 out of 3 projects, the first demonstrator secondment took place.