Tribological Investigation of Porcine Articular Cartilage

This poster examines the tribological properties and effective elastic modulus of porcine articular cartilage plugs. Two methods of obtaining an effective elastic modulus are explored for the different initial material conditions during the indentation loading and unloading. The average values of coefficient of friction varied from 0.04–0.14, but ended with a steady-state average of 0.06. It was validated that increasing pressure during sliding produces an increase in friction coefficient. From a contact model fit to the loading region of the indentation curve, effective elastic modulus had an average value of 300 MPa, which agrees with existing literature. From an examination of the linear portion of the unloading region of the indentation curve, the effective elastic modulus was an average of 8.9 MPa. A preliminary explanation for this is that before loading, a bulk material is present, but pressure effects could evacuate some of the interstitial fluid, leaving in the unloading curve an effective matrix without fluid.