This is the same biphasic consolidation model as the 3D explant simulator — the identical 1D pore-pressure diffusion PDE and fatigue-damage law — but drawn as three mathematical views instead of an instanced cylinder:
∂p/∂t = c_v · ∂²p/∂z² (pore pressure vs. depth z)
σ'(z,t) = σ(t) − p(z,t) (solid-matrix / effective stress)
dDamage/dt ∝ max(0, σ' − σ_th)²
- Top-left — depth profile. Pore pressure (teal) and solid-matrix stress (red) plotted against depth, from the free-draining articular surface (top) to the sealed bone interface (bottom), redrawn every frame straight from the PDE state.
- Top-right — depth–time heatmap. A scrolling strip where the vertical axis is depth and color is pore pressure fraction at that instant — the entire consolidation history painted at once, something the instantaneous 3D render cannot show. A red tick marks any depth/time where solid stress crossed the damage threshold.
- Bottom — readout strip chart. Fluid load support, peak solid stress and surface fibrillation scrolling over the last 20 s.
Losing proteoglycan lowers the aggregate modulus and raises hydraulic permeability at once, so c_v rises, pressure dissipates faster, and the solid network is exposed to damaging stress sooner — visible directly in the depth profile as the pressure curve collapsing toward zero more quickly, and in the heatmap as the "hot" (high-pressure) band shrinking with each cycle.