Prediction of stress-strain curves for TCP/PLLA composites: effect of hydrolysis and strain rate

In this study, effect of hydrolysis in simulated body environment on mechanical behavior of tricalcium phosphate (TCP)/poly(L-lactic acid) (PLLA) composites was analytically characterized. In order to predict stress–strain behavior after hydrolysis, damage of micromechanical analysis proposed by the authors was utilized. In this model, nonlinear behavior in stress–strain relationship was simulated considering interfacial debonding between TCP particle and PLLA matrix. For the purpose of deciding the interfacial strength, such as critical energy release rate, curve fitting was conducted on the result of the composites with 15wt% TCP content at three types of strain rates. Theoretical results on 5 and 10wt% composites using the interfacial strength obtained were in good agreement with experimental results. These results indicated that interfacial strength was dependent only on strain rate and was independent from TCP fraction.