Ramp-and-Hold Relaxation Test Data for Torsion of Ovine Brain Tissue

We performed three sets of ramp-and-hold relaxation tests in torsion on freshly slaughtered cylindrical ovine brain samples (25 mm diameter and ~10 mm height) at varying twist rates of {40, 240, 400} rad/m/s while keeping the twist fixed at ~88 rad/m. Each torsion test consisted of two phases: a ramp phase, in which the twist was increased linearly to ~88 rad/m over durations of {2.2, 0.367, 0.22} s, followed by a hold phase lasting 200 s, during which the final value of the twist reached at the end of the ramp phase was maintained. The torque and normal force required to twist the sample during the ramp phase and maintain it in its deformed state during the hold phase were recorded versus time. No pre-conditioning was performed on the samples, and each was tested only once before being discarded. A total of 30 samples were tested over several campaigns: 10 at 40 rad/m/s (S1–S10), 10 at 240 rad/m/s (S11–S20) and 10 at 400 rad/m/s (S21–S30). The tests were conducted using an Anton Paar MCR 302e rotational rheometer with parallel plate geometry. For more details, refer to the associated publication.