Theory 27/Rheology
Thickening Is a Stress Ratio
The claim
Discontinuous shear thickening occurs when the hydrodynamic stress exceeds the repulsive interparticle stress, so it appears at a critical ratio rather than a critical shear rate.
01The mechanism
Below the ratio, repulsion keeps particles apart; above it, hydrodynamics pushes them into contact and the suspension jams.
02Predictions
- P1Onset should track the stress ratio.
- P2Shear rate alone should mispredict across particle sizes.
03Refutation
Onset tracking shear rate would remove the ratio.