Unconventional fatigue failure of densified wood

Fatigue is a critical failure mechanism in various materials, often leading to catastrophic consequences. Designing materials with non-catastrophic fatigue failure is desirable yet challenging. This work presents the remarkable fatigue behavior of densified wood, exhibiting both a higher fatigue strength and non-catastrophic failure compared to natural wood. The improved bonding between wood fibers, primarily through hydrogen bonds, enables robust structural integrity even after fatigue failure. This mechanistic understanding offers insights for achieving non-catastrophic fatigue failure in diverse materials, presenting a fundamental principle for material design with broad implications.