Explorer Time dependent behaviour of trabecular bone at multiple load levels

General rights Copyright for the publications made accessible via the Edinburgh Research Explorer is retained by the author(s) and / or other copyright owners and it is a condition of accessing these publications that users recognise and abide by the legal requirements associated with these rights. Take down policy The University of Edinburgh has made every reasonable effort to ensure that Edinburgh Research Explorer content complies with UK legislation. If you believe that the public display of this file breaches copyright please contact [email protected] providing details, and we will remove access to the work immediately and investigate your claim. Abstract 19 The deformation of bone when subjected to loads is not instantaneous but varies 20 with time. To investigate this time-dependent behaviour sixteen bovine trabecular 21 bone specimens were subjected to compressive loading, creep, unloading and 22 recovery at multiple load levels corresponding to apparent strains of 2000 to 23 25000με. We found that: the time-dependent response of trabecular bone 24 comprises of both recoverable and irrecoverable strains; the strain response is 25 nonlinearly related to applied load levels; and the response is linked to bone 26 volume fraction. Although majority of strain is recovered after the load-creep-27 unload-recovery cycle some residual strain always exists. The analysis of results 28 indicates that trabecular bone becomes stiffer initially and then experiences 29 stiffness degradation with the increasing load levels. Steady state creep rate was 30 found to be dependent on applied stress level and bone volume fraction with a 31 power law relationship.