Heterogeneous stress transmission in 2D granular packings
In granular media, stress is transmitted heterogeneously through force chains —
networks of particles carrying above-average force. The force distribution P(f) ~ exp(-f/⟨f⟩)
is exponential (not Gaussian), indicating cooperative phenomena. Force chain thickness
is proportional to contact force magnitude. Strong chains form quasi-1D paths from
top to bottom wall, bypassing many particles.