Method for assessing fatigue damage and a fatigue life based on a crystal plastic welding process model

A method for welding of a material based on a crystal plastic welding process model, comprising the following steps:

• S1, establishing a crystal plastic welding computational mesh model based on a macroscopic model size and a microscopic characterization of the material;
• S2, establishing a crystal plastic welding process constitutive model based on the crystal plastic welding computational mesh model;
• and
• S3, assessing a fatigue damage and a fatigue life of the material based on the crystal plastic welding process constitutive model;
• S4, welding the material based on the fatigue damage and the fatigue life of the material;
• wherein, the step S1 specifically comprises the following steps:
• S11, generating, by an image pixel discretization technology, coordinate information of a crystal grain and a crystal nucleus on a mesoscopic scale of a welding area based on the macroscopic model size and information of the microscopic characterization of the material;
• S12, using, by a Voronoi algorithm, the coordinate information of the crystal grain and the crystal nucleus, to generate a two-dimensional crystal model map or a three-dimensional crystal model map;
• S13, using, by finite element mesh generation software, the two-dimensional crystal model map or the three-dimensional crystal model map to generate a mesoscopic Voronoi crystal plastic mesh model according to a requirement for a macroscopic simulation of a welding process;
• S14, constructing a mesh model by adding a property of the material, a parameter of the welding process and fixture constraint information to the mesoscopic Voronoi crystal plastic mesh model via computer engineering software;
• and
• S15, when the mesh model is validated for eligibility, outputting the mesh model;
• when the mesh model is not validated for eligibility, modifying the coordinate information of the crystal grain and the crystal nucleus and returning to the step S12.