Observations in compression tests of articular cartilage have revealed unequal load increments for compression and release of the same amplitude applied to a disk with an identical previously imposed compression (in equilibrium). The mechanism of this asymmetric transient response is investigated here using a nonlinear fibril-reinforced model. It is found that the asymmetry is predominantly produced by the fibril stiffening with its tensile strain. In addition, allowing the hydraulic permeability to decrease significantly with compressive dilatation of cartilage increases the transient fibril strain, resulting in a stronger asymmetry. Large deformation also enhances the asymmetry as a consequence of stronger fibril stiffening.

Issue Section:
Technical Brief
Keywords:
biological tissues, biomechanics, Cartilage Mechanics, Compression-Release, Poroelasticity, Fibril Reinforcement, Fibril Stiffening
Topics:
Cartilage, Compression, Stress, Transients (Dynamics), Permeability
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Copyright © 2001
 by ASME
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