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A Coupled Experiment-finite Element Modeling Methodology for Assessing High Strain Rate Mechanical Response of Soft Biomaterials
Published on: May 18, 2015
Experimental characterization and finite element implementation of soft tissue nonlinear viscoelasticity
Kevin L Troyer1, Snehal S Shetye, Christian M Puttlitz
1Department of Mechanical Engineering, Colorado State University, Fort Collins, CO 80523-1374, USA.
Journal of Biomechanical Engineering
|February 8, 2013
Summary
This study introduces a new nonlinear viscoelastic formulation for finite element models of joints. It improves predictions for dynamic and static loading by accurately capturing soft tissue behavior.
Area of Science:
- Biomechanics
- Computational mechanics
- Biomaterials
Background:
- Current finite element (FE) models of articular joints simplify soft tissue behavior, compromising predictive accuracy under dynamic and static loading.
- Existing models often neglect transient viscoelastic effects during loading, further reducing reliability.
Purpose of the Study:
- To develop and validate a novel, computationally tractable nonlinear viscoelastic formulation for FE analysis of joint structures.
- To introduce an experimental characterization technique that accounts for relaxation during the loading phase.
Main Methods:
- Derived a phenomenological nonlinear viscoelastic formulation based on single integral nonlinear superposition.
- Developed an experimental characterization method incorporating in-loading relaxation.
- Validated the formulation and method against an independent analytical model and a prior characterization technique.
Main Results:
- The novel FE approximations showed good agreement with the analytical solution for static and dynamic loading.
- Predictive accuracy was significantly influenced by the experimental characterization method used.
- The new formulation and characterization technique demonstrated improved fidelity.
Conclusions:
- The developed nonlinear viscoelastic formulation and experimental technique enhance FE model accuracy for joint simulations.
- Accurate characterization of transient soft tissue behavior is crucial for reliable joint modeling.
- This approach promises improved predictions for connective tissues under various loading conditions.
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