Abstract
Fresh porcine spinal cords (N = 5) were obtained at a local abattoir, and intact nerve roots were excised using a surgical scalpel and fine forceps with a special caution. In total, 77 fiber bundles with a dimension of 30 mm in length and 0.5 mm in diameter were isolated from the excised nerve roots. By conducting a series of uniaxial stretching tests at three different velocities, 0.1, 1, and 10 mm/s, we revealed that mechanical properties of fiber bundles were relatively insensitive to strain rates under such a sub-impulsive loading condition. On average, elastic moduli, linear portion of stress-strain curve, resulted in 3.8, 3.3, and 4.5 MPa for 0.1, 1, and 10 mm/s, respectively. In addition, strain at failure was found to be almost constant, ∼0.15, irrespective of a 100-fold increase in the applied loading rate, while axial strains were distributed non-uniformly along fiber direction.
