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Abstract 2D hybrid organic–inorganic perovskites (HOIPs) are commonly found under subcritical cyclic stresses and suffer from fatigue issues during device operation. However, their fatigue properties remain unknown. Here, the fatigue behavior of (C₄H₉‐NH₃)₂(CH₃NH₃)₂Pb₃I₁₀, the archetype 2D HOIP, is systematically investigated by atomic force microscopy (AFM). It is found that 2D HOIPs are much more fatigue resilient than polymers and can survive over 1 billion cycles. 2D HOIPs tend to exhibit brittle failure at high mean stress levels, but behave as ductile materials at low mean stress levels. These results suggest the presence of a plastic deformation mechanism in these ionic 2D HOIPs at low mean stress levels, which may contribute to the long fatigue lifetime, but is inhibited at higher mean stresses. The stiffness and strength of 2D HOIPs are gradually weakened under subcritical loading, potentially as a result of stress‐induced defect nucleation and accumulation. The cyclic loading component can further accelerate this process. The fatigue lifetime of 2D HOIPs can be extended by reducing the mean stress, stress amplitude, or increasing the thickness. These results can provide indispensable insights into designing and engineering 2D HOIPs and other hybrid organic–inorganic materials for long‐term mechanical durability. 

Buffeting analysis plays an important role in the wind-resistant design of long-span bridges. While computational methods have been widely used in the study of self-excited forces on bridge sections, there is very little work on applying advanced simulation to buffeting analysis. In an effort to address this shortcoming, we developed a framework for the buffeting simulation of bridge sections subjected to turbulent flows. We carry out simulations of a rectangular bridge section with aspect ratio 10 and compute its aerodynamic admittance functions. The simulations show good agreement with airfoil theory and experimental observations. It was found that inflow turbulence plays an important role in obtaining accurate wind loads on the bridge sections. The proposed methodology is envisioned to have practical impact in wind engineering of structures in the future.