A viscoelastic, viscoplastic model of cortical bone valid at low and high strain rates

作者：Johnson T P M^*; Socrate S; Boyce M C

来源：Acta Biomaterialia, 2010, 6(10): 4073-4080.

DOI：10.1016/j.actbio.2010.04.017

• Cortical bone
• Viscoelastic
• Viscoplastic
• High strain rate
• Constitutive model

The stiess-strain behavior of cortical bone is well known to be strain-rate dependent, exhibiting both viscoelastic and viscoplastic behavior Viscoelasticity has been demonstrated in literature data with initial modulus increasing by more than a factor of 2 as applied strain rate is increased from 0 001 to 1500 s(-1). A strong dependence of yield on strain rate has also been reported in the literature, with the yield stress at 250 s(-1) having been observed to be more than twice that at 0 001 s(-1). demonstrating the material viscoplasticity. Constitutive models which capture this rate-dependent behavior from very low to very high strain rates are required in order to model and simulate the full range of loading conditions which may be experienced in vivo; particularly those involving impact, ballistic and blast events This paper proposes a new viscoelastic. viscoplastic constitutive model which has been developed to meet these requirements The model is fitted to three sets of stress-strain measurements from the literature and shown to be valid at strain rates ranging over seven orders of magnitude.

• 出版日期2010-10