Auxetic foam pads : experiments and parameters identification
Résumé
Auxetic materials are known to exhibit smart and efficient mechanical properties such as high energy absorption and fracture resistance been
able to be used for a variety of applications (personal protection clothing, packing material, robust shock absorbing material, sponge mops and
filtration). The particular hinge-like structures of auxetic materials typically induce macroscopic negative Poisson's ratio. The material used in this
work has been obtained from conventional foam that becomes auxetic after a specific forming process. Numerical and experimental
approaches are conducted using conventional and auxetic samples made from the same base material, together with classical melamine
foam for comparison purpose. Several acoustic properties are investigated. Finally, in order to identify some parameters values including the Poisson's ratio, a procedure allowing identification from simple measurements has been tested: a preliminary sensitivity study is performed, and the optimization step is then conducted in order to efficiency identify the parameters from experimental measurements. The particular case of the Poisson's ratio is considered in details. Aspects related to visibility of the parameter, anisotropy of the material and confidence of the identification are discussed.