Progressive damage analysis of a bioresorbable composite subject to three-point bending

The focus of this paper is to investigate the deformation response of a new class of bioresorbable composites used for bone fixation devices under flexural loading. The Digital Image Correlation (DIC) technique are utilized to map the deformation history and identify the damage locations. Since the damage propagation path needs to be calculated by the simulation, a fracture energy based Smeared Crack Approach (SCA) is revisited and implemented in the Finite Element Analysis (FEA). In the new SCA model, 2D crack morphology incorporating two crack components are discussed. In addition, the stress degradation rule after the damage initiation is revised to guarantee the energy conservation. Compared with the analytical solution, the new SCA model is validated by the benchmark examples of the Double-Cantilever Beam (DCB) and the End Notched Flexure (ENF) simulations. The results demonstrate the predictive capability of the SCA to capture both the mode-I and mode-II failure modes. The new SCA model is further employed to predict the failure response of the bioresorbable composite under three-point bending, which shows a good correlation with the experiment. Based on the FE simulation results, a linear regression model is developed to elucidate the effect of critical stress and fracture energy on the resulting flexural response. The numerical methods in this paper can be used as an efficient tool in designing the bioresorbable composite for controlled mechanical performance.