FIGURE 2.

(A) Schematic of biphasic FEM simulating in vitro ploughing experiments. Static normal compressive load (F_compression) on the indenter was kept constant for a designated time (top right), and then, the indenter was oscillated along the disc’s mediolateral axis (bottom right). The sandpaper annulus that prevented disc translation in vitro³ was simulated in the model by fixing the far left 1 mm of the disc’s bottom surface while the remainder was allowed to slide horizontally. (B) Vertical displacement of the indenter during the initial compression period (t<t₀; A top right). Note that the stress relaxation period after initial compression was neglected to be consistent with the corresponding experimental setting (t₀=t₁; A bottom right).^3,12,13 (C) Model prediction of total normal stress during a full cycle of indenter oscillation at linearly aligned pressure gauges (PG) 4–6 separated by 3 mm. PG5 was under the disc centre