Research On The Numerical Methods Of The Determination Of Multiple Stress Intensity Factors

Based on the basic equations of the elasticity plane problem in the thesis, stress singularity eigenequations and displacement fields together with singular stress fields near the V-notch tip and the crack tip for homogeneous materials and the interface edge of bonded materials are introduced. On the base of regular numerical analysis results, numerical methods using one stress to determine the orders for single and double stress singularity problems are proposed, besides, numerical methods to determine the stress intensity factors for single and double stress singularity problems are also given. By utilizing the above methods and the results of the finite element program named Algor, the paper carries through particular calculations corresponding to the single stress singularity and the double stress singularity issues, which consist of the crack for model Ⅰ, the crack for model Ⅰ and Ⅱ, V-notch and the interface edge of bonded materials. The results show that the minimal changing direction of (σ1-σ3) is the best one to determine the stress singularity orders as well as stress intensity factors, moreover, the numerical methods advanced in the paper have the advantages of simplicity, applicability and high accuracy, so that they are perfectly applied for the projects.