Mechanical Response and Damage Evolution of PMMA-Based Bone Cement from Compressive Calibration to Shear Prediction

In this study, a three-dimensional viscoelastic lattice spring model (VLSM) is employed to evaluate the transferability of compression-calibrated material parameters to shear loading for poly(methyl methacrylate) (PMMA)-based bone cement (BC). The model is first calibrated using compressive stress-strain data and then applied to shear loading without further parameter re-identification. The model reproduces the main features of the compressive response, predicts the shear stress-strain response, and resolves the associated progression from homogeneous elastic deformation to diffuse microdamage and ultimately to localized failure. Moreover, analyses considering variations in shear location and shear-plane size further clarify the relationship between shear stress-strain response and damage patterns, revealing that more peripheral loading and smaller shear planes sustain higher load-carrying capacity due to differences in crack propagation pathways. Finally, parametric investigations demonstrate that loading rate, porosity, and BaSO4 content exert systematic influences on the macroscopic stress-strain response and damage development. These findings suggest that the VLSM can transfer a compression-calibrated parameter set to shear loading, enabling analysis of the shear mechanical response and damage evolution of PMMA-based BC.