ABSTRACT
Characterization of the impact behavior of tibial bone is attempted to help understand injury and to improve the design of protective devices. A three-point bending test using a drop tower setup was used to simulate impacts typical in automotive crashes. Piezoelectric load cells were used to record the impact force and reaction forces at the two supports. A data acquisition system was used to record the load-time history, and a high-speed digital camera was used to obtain the displacement-time history of the test. Nine tests were performed on the goat tibia at impact velocities of about 1.0, 2.0, and 3.25 m/s in the posterior to anterior impact direction at the mid-shaft of the bone. The average span length was 130 mm, and the average weight of bone specimens was 73 g. The force-time plots were non-linear in all the cases. The maximum load before failure initiation does not always rise with impact velocities, suggesting additional parameters’ role in its determination. Time to visible failure initiation decreased with increased impact velocity, while the average energy absorption capacity increased with increased impact velocity. An increase in the loading rate and stiffness with increased impact velocity indicates strain rate dependency of bone stiffness.
