On the mechanical characterization of bovine bone tissue under compressive loading

Abstract

This study reveals a pioneer characterization of bovine trabecular bone tissue under dynamic compressive loading in the range of 20-140 oC, within physiological loading frequencies (1-20 Hz). The presented results demonstrate that the viscous behaviour in compression mode up to 140 oC is regulated by the collagen viscoelastic properties, showing three frequency-independent main peaks in tanδ and loss modulus at 75, 100, and 130 oC. The referred peaks are, respectively, related to crystalline structure breakdown, water structural evaporation, and the glass transition temperature (Tg) of collagen. At these low frequencies, the system is governed by a frequency-dependent elastic response and a frequency- independent energy dissipation. However, an additional experimental test at physiological temperature (37 oC), in the range of 10-200 Hz, has shown that bone trabecular tissue submitted to compressive loading at higher frequencies is ruled by a frequency-dependent behaviour of the viscous component.