Element-free Method For Thermoelastic Fracture Mechanics Based On The Cohesive Zone And Crack Segments Model

The change of temperature is an important reason for the generation and expansion of cracks in concrete and other engineering structures.The theoretical research and numerical simulation of thermoelastic fracture mechanics have important engineering significance.Although the more researchers have done a lot of research work on the numerical simulation of thermoelastic fracture mechanics,the problems such as discontinuity in temperature and displacement field,singularity of crack tip and cracking criterion have been the problem in numerical simulation.So we propose a method based on the crack and segmentation model to study the thermoelastic fracture of the material by mesh-free method.In view of this situation,this paper uses the mesh-free method numerical simulation,carried out the following research work:In the problem domain,a series of cohesive segments are combined instead of successive cracks,where the crack is considered to be a combination of a series of crack segments and a new crack segment at the crack tip on the original node.The new cohesive segments satisfies the cracking criterion of the cohesive force model at the node,when the principal stress at the tip of the crack reaches uniaxial tensile strength,a new set of crack segments is introduced to achieve crack propagation.Using the moving least-square shape functions as the partition of unity,the discontinuity field is approximated with extra degrees of freedom at the existing nodes.Cohesive constitutive laws are used to model force and heat transfer through cracks.The element-free method is established based on the crack segments and cohesive zone models.Mechanical and temperature fields are incorporated into a coupled nonlinear system,and the crack problem is iteratively solved.Thecomputational code is written with the Fortran language,and the chosen numerical examples illustrate the efficiency and flexibility of the proposed method.