An extended abstract describing my independent research on passive reconfiguration of tree branches under wind loading was accepted for presentation at the 16th Constructal Law Conference in Paris, France in October, 2026.
The work, adapted from my term paper from the Design in Nature course by Dr. Adrian Bejan, was inspired by weeping willow branches elastically deforming under high wind speeds.
Abstract:
The weeping willow tree exemplifies a constructal design: flexible branches elastically reconfigure under wind loads for greater freedom of stress flows. We model the flexible branch as a slender beam under aerodynamic loading with a variable effective area determined by a reconfiguration factor. This formulation yields a governing dimensionless parameter (Λ) that captures threshold behavior under strong and weak wind regimes when scaling laws are applied. In the wind-dominated regime (Λ≫1), reconfiguration reduces bending moments and permits longer branches relative to rigid counterparts; in sheltered conditions (Λ≪1), the advantage vanishes. Analysis suggests this flow architecture evolved to reduce stress constraints and promote greater branch length and leaf area.
Weeping Willow, Claude Monet, 1918-1919