XFEM for multiphysics analysis of edge dislocations with nonuniform misfit strain: A novel enrichment implementation

In this work, the eXtended finite element method (XFEM) is implemented for the multiphysics analysis of edge dislocations near a heterostructure (bi-material) interface with nonuniform misfit strain. A novel enrichment is defined to incorporate the singular behavior of the electric potential due to dislocation. Nonlinear material properties due to temperature are taken for a thermo-electro-elastic analysis. The constituting materials having different lattice parameters result in a mismatch–misfit​ strain near the interface. This nonuniform misfit strain distribution affects the dislocations near the bi-material interface. Volterra dislocation modeling is performed to obtain all the primary and secondary fields around dislocations. An expression of the Peach–Koehler force considering the combined effect of the multiple fields is proposed. The results are obtained when the misfit strain is present on one side of the interface and both sides of the interface. A comparative study is performed on the Peach–Koehler force obtained in different cases of the misfit consideration with the case when the misfit strain is absent. Also for the case when the misfit strain is taken on the same side of the interface, the Peach–Koehler force is obtained by varying the misfit percentages corresponding to the different amounts of misfit relaxation.