A three-dimensional visco-hyperelastic FE model for simulating the mechanical dynamic response of preloaded phalanges

Area of Science:

• Biomechanics and Biomedical Engineering
• Occupational Health and Safety
• Soft Tissue Mechanics

Background:

• Vibration exposure can affect the digital arterial network, potentially disturbing fingertip vasoconstriction.
• Understanding the mechanical and biological factors influencing these effects is crucial for prediction and prevention.

Purpose of the Study:

• To develop and validate a novel dissipative constitutive law for fingertip soft tissue.
• To enable finite element modeling of the mechanical response of fingertips to vibration.
• To contribute to a multi-scale strategy for understanding vibration effects on digital arteries.

Main Methods:

• Developed a two-stage visco-hyperelastic constitutive law combining static nonlinear and spectral dissipative models.
• Identified Ogden-Hill law parameters using constrained optimization.
• Proposed a spectral domain viscous dissipation model based on linearized quasi-linear viscoelasticity and relaxation spectra.

Main Results:

• The model achieved high accuracy, with relative errors below 5% for static and 8% for dynamic stiffness.
• High mechanical pressure and tangential stress were observed in soft tissues near excitation and in bones/cartilage.
• Significant mechanical power dissipation occurred only near the vibration contact area.

Conclusions:

• A new spectral dissipative law for fingertip soft tissues was successfully implemented and parameterized.
• This model provides a foundation for predicting vibration effects on digital arteries.
• Potential applications include refining vibration dose assessment in occupational health and screening for connective tissue diseases.