The Analysis Of Stress Singularities Of Two-Dimensional Interface Edge And Interface Crack

Firstly, on the base of basic knowledge of the interfacial mechanics, this thesis use the method of solving the planar interface end stress singularity theory to study the impact on stress singularity by changing the shape of the interface edge. Then, this thesis introduce the methods which are taken to solve the index of stress singularity at the interface edge by finite element software ANSYS. Secondly, we discuss the influence of material matching combination, geometric composition and arc transition at the interface edge to interface edge stress singularity. Finally, this thesis use finite element method to solve the stress intensity factors, and we study the effect of crack length and material matching combination on the stress intensity factors.Analysis shows that the interface edge stress singularity mainly has the following four cases:no singularity, single stress singularity, double real stress singularity, and double oscillating stress singularity. And as the combined angle increases, the four cases appear in turn and the stress singularity gradually increases. In addition, we found that numerical methods could meet the accuracy requirements by numerical comparison with the theoretical solution. What’s more, when the poisson rate is the same, the greater the difference of the two material Young’s modulus is, the more serious the stress singularity will be. When the Young’s modulus rate is the same, the change of the poisson can make the stress singularity change. And as the combined angle increases, the stress singularity gradually increases. On the one hand, we can conclude that the cases of arc transition weaken the stress singularity at the interface edge. On the other hand, the greater the transition radius is, the smaller the value of stress at the interface edge will be, however, different transition arc has almost the same degree of improvement of stress singularity at the interface edge. Finally, the the stress interaction integral method that is used to solve the stress intensity factors has well stabilization, and as the crack length increases, the stress intensity factors gradually increases. When the crack length and the poisson rate are the same, as the difference of the two material Young’s modulus increase, the stress intensity factors gradually increases. When the crack length and the Young’s modulus rate are the same, the stress intensity factors will change as the poisson changes.