A PHASE FIELD METHOD BASED FRACTURE ANALYSIS OF FUNCTIONALLY GRADED PLATES

Due to the graded distributions of their material properties, functionally gradient materials (FGMs) have more complicated fracture behavior than homogeneous materials, making it difficult to simulate their failure mechanism. The current work makes use of special shape functions and informed mesh refinement schemes in conjunction with the famous phase-field method to render the fracture computations faster at the same time retaining accuracy in the prediction. To this end, exponential shape finite element shape functions are introduced instead of standard bilinear shape functions conventionally used in finite element calculations accompanying the phase-field method. The exponential characteristic of such special shape functions is made use of to reduce the mesh refinement level at crack propagation paths. This study suggests a learned orientation scheme for these shape functions, informed by an approximate analysis using bilinear shape functions carried out during the analysis itself. Fracture simulations are carried out in functionally graded plates with different gradation schemes, and their effect on fracture resistance is investigated. Computational efforts incurred in the present implementation are compared with existing schemes using bilinear shape functions.