Proximal humerus impacted fractures are of clinical concern in the elderly population. Prediction of such fractures by CT-based finite element methods encounters several major obstacles such as heterogeneous mechanical properties and fracture due to compressive strains. We herein propose to investigate a variation of the phase field method (PFM) embedded into the finite cell method (FCM) to simulate impacted humeral fractures in fresh frozen human humeri. The force-strain response, failure loads and the fracture path are compared to experimental observations for validation purposes. The PFM (by means of the regularization parameter ℓ0) is first calibrated by one experiment and thereafter used for the prediction of the mechanical response of two other human fresh frozen humeri. All humeri are fractured at the surgical neck and strains are monitored by Digital Image Correlation (DIC). Experimental strains in the elastic regime are reproduced with good agreement (R2=0.726), similarly to the validated finite element method (Dahan et al., 2022). The failure pattern and fracture evolution at the surgical neck predicted by the PFM mimic extremely well the experimental observations for all three humeri. The maximum relative error in the computed failure loads is 3.8%. To the best of our knowledge this is the first method that can predict well the experimental compressive failure pattern as well as the force-strain relationship in proximal humerus fractures.
|Journal||Journal of the Mechanical Behavior of Biomedical Materials|
|State||Published - Oct 2022|
Bibliographical noteFunding Information:
LH, SK and ER gratefully acknowledge the funding through Deutsche Forschungsgemeinschaft (DFG), Germany for its financial support through the TUM International Graduate School of Science and Engineering (IGSSE), GSC 81. Moreover, they would like to thank the Competence Network for Scientific High Performance Computing in Bavaria (KONWIHR) and the Gauss Centre for Supercomputing e.V. ( www.gauss-centre.eu ) for the financial support and computing time provided on the Linux Cluster CoolMUC-2 at Leibniz Supercomputing Centre ( www.lrz.de ).
© 2022 Elsevier Ltd
- Brittle fracture
- Finite Cell Method
- Humerus fracture
- Iso-geometric analysis
- Phase-field modeling