Mesoscopic model for the fracture of polymethyl methacrylate bone cement

Abstract

Polymethyl methacrylate (PMMA) bone cement is widely used for biomedical applications. The fracture toughness (KIC) and tensile strength (ft) are two critical indicators directly influencing its safety and durability. However, different test methods are currently being used to determine the material parameters (KIC &ft) of PMMA bone cement. In order to address this issue, an innovative design method only employing the modified wedge split specimens is presented in this study to determine the PMMA bone cement material parameters (KIC &ft) simultaneously. Due to the discrete peak load Pmax, the resulting material parameters (KIC &ft) are discrete. Considering the discreteness of the material parameters (KIC &ft), their true values for PMMA bone cement were calculated through the standard statistical method. Further, a two-point simple method to determine the material parameters of PMMA bone cement has been proposed based on the equivalent area Ae. Finally, the numerical model of PMMA bone cement was developed from the mesoscopic level. The discrete mechanism of the peak load Pmax of PMMA bone cement due to the variation in particle contact strength was interpreted from the mesoscopic perspective.