Sensitivity and stability analysis of a nonlinear material model of cervical intervertebral disc under cyclic loads using the finite element method. Biomed Sci Instrum 2014;50:19-30
Date
11/19/2014Pubmed ID
25405399Abstract
It is known that the human spine exhibits non-linear behavior, and its intervertebral discs play a role in the mechanism of internal load transfer. It is important to simulate its nonlinear behavior in computational models for better delineation of intrinsic responses, especially during cyclic loading activities, a mode pertinent to civilian and military populations. For developing a robust material model of the disc, this study used experimental tensile-compressive cyclic loading responses from four human cadaver cervical functional spinal units. Disc deformations were measured using an ultrasound system at 42 samples per second. Using experimental data, a three-network non-linear material model was developed using an optimization procedure and finite-element analysis. The model used 12 parameters to capture loading and unloading in tension and compression, including hysteresis. A sensitivity analysis performed to test the robustness of the material model indicated that seven of the 12 parameters were sensitive to tension, compressive, or both loading modes. Stability analysis was also performed under nine different loading conditions. The developed material model is robust and stable to capture intervertebral disc responses in tensile-compressive cyclic loading and can be used in future finite-element models.
Author List
Arun MW, Yoganandan N, Stemper BD, Zheng M, Masoudi A, Snyder BAuthors
Brian Stemper PhD Professor in the Biomedical Engineering department at Medical College of WisconsinNarayan Yoganandan PhD Professor in the Neurosurgery department at Medical College of Wisconsin
