Effect of groove on bone fracture toughness

Abstract

When testing for the effects of bone orientation on mode I fracture toughness, compact tension specimens are grooved with a V-notch to provide a crack guide. The effect of grooving on the expressions for the critical stress intensity factor ( K c ) and the critical strain energy release rate ( G c ) for mode I fracture toughness was investigated. Experiments were performed using grooved and ungrooved bovine compact tension specimens. The results indicate that the standard expression used to determine K c for a compact tension specimen requires modification. The thickness ( B) must be modified to account for the thickness between the grooves ( B n). The thickness used in the standard expression is replaced by an effective thickness written as ( BB n) 0.5. It was also found that the thickness between the grooves should be used in the standard formula for G c .