Study On The Interaction Between Dislocation Loops And Interface In Three-dimensional Elastic Anisotropic Multilayered Materials

Based on the latest research results of the elastic field of dislocation loops in a threedimensional elastic anisotropic homogeneous medium.The interaction between dislocation loops and interfaces in bimaterials is studied,and a simplified three-layer material model containing dislocation is proposed.The interaction between dislocation loops and two interfaces in the three-layer material have also been studied.The following two parts of work has been done in this article:1.The displacement and stress fields generated by the triangular dislocation loops in the elastic anisotropic biomaterials is firstly derived.Based on the derivation results,MATLAB programs are written to obtain the numerical solution of stress field of the dislocation loops at any point in the bimaterials space.A macroscopic model without dislocation loops is created in ABAQUS.The stress on the surface of the model is zero because the surface is free surface,and the total stress of the dislocation loop on the surface is the superposition of the stress field and image stress field generated by the dislocation loop at this position.In this case,the image stress field is the inverse of the stress field generated by the dislocation loop,so the elastic field generated by the dislocation loop can be simulated by the image force derived from the image stress.In this way,the interaction between the dislocation loop and the interface can be studied.In this paper,We will consider the influence of material thickness,the size of the dislocation loop,the distance between the dislocation loops and the interface,and the change of the crystal orientation,on the stress and displacement at the interface.2.The displacement field and stress field of the triangle dislocation loop in the whole space of the elastic anisotropic single material is firstly derived.Based on the derivation results MATLAB program are written,the ABAQUS model is established.We can simulate the elastic field generated by the dislocation loop in the single layer with a similar method.Combined with the three-layer simplified model in which the dislocation loops are placed in the middle layer,the volumetric force is obtained by processing the single-layer material model.The volumetric force is applied as a load to the three-layer material model,and the elastic field three-layer material can be simulated.And then study the interaction between the dislocation loop and the two interfaces.The simplified model of this paper is based on the stacking scheme of Giessen and Needleman,which is applicable to the case of more layers of materials and dislocations loop in multilayer materials.