Buckling behaviour of auxetic domes under external pressure

Abstract

In view of ongoing great interest in novel materials exhibiting Negative Poisson Ratio (NPR), the current study examines its influence on buckling behaviour of externally pressurized​ torispherical pressure vessel closures. Failure pressures are computed for the range of Poisson’s ratio: −1.0 ≤ν < 0.5. The following wall constructions are considered: (i) single auxetic layer, (ii) outer metallic skin supported on inside by an auxetic layer, and (iii) sandwich with auxetic core. Both metallic and auxetic layers are assumed to be isotropic, and exhibit elastic, perfectly plastic behaviour.Results of this numerical study show that the inclusion of auxetic can lead to 89% gain in failure pressures above auxetic-free configuration of the wall. The range of analysed diameter-to-wall thickness ratio varied between 666 and 2000. Two layer wall construction (metallic skin supported by auxetic layer), was found to exhibit better performance than the equivalent sandwich configuration.