In the search for innovative solutions for lightweight materials with high absorption capacity, this research specifically investigates the hyperelastic behaviour of auxetic flexible structures. Auxetic structures, which are characterised by a negative Poisson's ratio, offer high energy absorption and low weight, making them particularly suitable for lightweight applications such as aerospace. This study, which combines experimental and numerical approaches, provides insights into the mechanical behaviour of flexible, additively manufactured auxetic structures to improve energy absorption. In the experimental phase, the strains and their derivatives in flexible, planar structures are accurately measured using a digital image correlation (DIC) system during tensile tests. The analysis focuses on how the dynamic Poisson's ratio is affected during the test. The numerical aspect uses a finite element simulation with the hyperelastic Mooney-Rivlin material model to characterise these structures at the macro level. The comparison between experimental and simulation results shows a coherent correlation, which proves their reliability. Based on this simulation, the strains are compared with the experimental results for validation and the stresses and absorbed energy are calculated. Based on this, 3D structures are analysed. In an experimental study, flexible 3D-printed samples of thin-walled tubes surrounded by an auxetic shell are used for compression tests. The results show that the inclusion of auxetic structures leads to higher energy absorption compared to cylindrical walls of the same mass.