Editing Soft tissue (section)

=== Pseudoelasticity ===
Even though soft tissues have viscoelastic properties, i.e. stress as function of strain rate, it can be approximated by a [[Hyperelastic material|hyperelastic]] model after '''precondition''' to a load pattern. After some cycles of loading and unloading the material, the mechanical response becomes independent of strain rate.
:<math>\mathbf{S}=\mathbf{S}(\mathbf{E},\dot{\mathbf{E}}) \quad\rightarrow\quad \mathbf{S}=\mathbf{S}(\mathbf{E})</math>

Despite the independence of strain rate, preconditioned soft tissues still present hysteresis, so the mechanical response can be modeled as hyperelastic with different material constants at loading and unloading. By this method the elasticity theory is used to model an inelastic material. Fung has called this model as '''pseudoelastic''' to point out that the material is not truly elastic.<ref name="Fung"/>