2025/11/22 by Hui Li, Shanyong Wang
Engineering · Materials Science · #Numerical methods in engineering #Solidification and crystal growth phenomena #Microstructure and mechanical properties
paper · doi:10.1016/j.jmps.2025.106431
Phase-field modelling of compressive–shear fracture in anisotropic materials with tension-compression asymmetry remains a major challenge, despite its significance in geomechanics and structural engineering. To this end, a novel hybrid phase-field model with an orthogonality-based strain decomposition is proposed for modelling of mixed-mode brittle fracture in orthotropic/anisotropic materials. In this model, the strain is first mapped into an auxiliary space via the square root of the stiffness (ℂ 1/2 ) and thus is orthogonally decomposed into volumetric tensile, volumetric compressive, and deviatoric parts. The deviatoric strain is further partitioned by spectral decomposition into positive and negative items. This volumetric–deviatoric–spectral strain split results in a fivefold partition of the strain energy. A new driving force is then proposed by combining the Mohr–Coulomb criterion and three fracture energies with the five energy components within the AT 1 phase-field finite-element formulation. The present model is validated through 2D tension and shear tests on single-notched plates and 2D/3D compression tests on single-hole plates. It is found that the simulated results agree well with published numerical and experimental data, and the accuracy and capability of the model for modelling mixed-mode fracture in anisotropic materials under shear/compression are well validated.