A Constitutive Equation for the Canine Anterior Cruciate Ligament

Abstract

A simplified constitutive equation is proposed to characterize the nonlinear viscoelastic behavior of the canine anterior cruciate ligament. The theory contains a single relaxation function which was measured experimentally by a series of uniaxial relaxation tests. To test the applicability of the theory, the experimentally determined function was used to attempt to predict the results of a special log-ramp test, as well as a constant strain-rate test. It was found that the simplified equation predicted stress results which were somewhat higher than experiment throughout much of the strain range tested.