Figure 6.

Finite-element simulation of the pore pressure at frequency of f = 55 Hz in normal (E_L= 0.1 MPa, E_f = 5 MPa, k = 5.4 × 10⁻¹⁵ m⁴ N⁻¹ s⁻¹, υ = 0.1) and GAG-depleted cartilage (E_L = 0.08 MPa, E_f = 4 MPa, k = 1.3 × 10⁻¹³ m⁴ N⁻¹ s⁻¹, υ = 0.1) confirms the effect of GAG depletion on fluid pressurization in dynamic loading, which consequently alters the nanoscale dynamic functions of cartilage, such as self-stiffening and energy dissipation. The pressure profile shown for each condition is the maximum amplitude of the pore pressure versus depth at the frequency of f = 55 Hz, the frequency at which the phase angle, ϕ, measured for the normal cartilage peaks.