High-cycle fatigue of tri- and tetra-anti-chiral auxetic structures: Experimental and numerical investigation

The investigation of the fatigue behaviour of two chiral auxetic cellular structures made of aluminium alloy 5083-H111 is presented in this study. Experimental and numerical tests were conducted under force control at different stress amplitudes in the high-cycle fatigue (HCF) regime. Based on the results, S-N curves were constructed, and the fatigue life of two auxetic geometries was determined. The numerical study was done using an elasto-plastic material model and stress-life approach to assess their fatigue life. The results showed that the tri-anti-chiral structure had a higher fatigue resistance compared to the tetra-anti-chiral structure. A good correlation was achieved between the numerical and experimental results, both in fatigue life predictions and in crack initiation regions. Additionally, a parametric study was conducted to assess the impact of modifying the node-strut junction radius on fatigue life.