Numerical method for extracting hybrid dispersion crack tip parameters of non-uniform material

Abstract

The invention discloses a numerical method for extracting a tip parameter of a mixed type dispersion crack of a non-uniform material. The method comprises the following steps of: 1, determining a J integral expression of the mixed type dispersion crack of the non-uniform material with integral region independence and a corresponding finite element discrete format; 2, establishing a finite element model containing the mixed type dispersion cracks and dividing finite element grids; 3, solving a nonlinear control equation of the fracture phase field model by adopting a Newton-Raphson method; and 4, according to a finite element discrete format of the J integral of the mixed type dispersion crack of the non-uniform material, solving mixed type dispersion crack tip parameters-mixed type stress intensity factors KI and KII based on a finite element calculation result. According to the method, the parameters of the mixed type dispersion crack tip of the non-uniform material are accurately solved, and the defect that the stress state of the mixed type dispersion crack tip cannot be accurately described through a traditional fracture phase field method is overcome.

Description

technical field [0001] The invention belongs to the technical field of computer simulation, and relates to a method for solving the fracture problem of non-uniform materials, in particular to a numerical method for extracting the parameters of the tip of mixed diffuse cracks of non-uniform materials. Background technique [0002] Inhomogeneous materials, which are widely used in many fields of national economy such as aerospace, often face very complicated service conditions. Under complex loading conditions, mixed cracks appearing in heterogeneous materials are one of the key factors limiting their service performance. Compared with the traditional fracture mechanics method, the fracture phase field method uses a finite-width diffuse crack model, which can characterize crack nucleation and crack propagation behavior under complex load conditions, and can be used to study the mixing of heterogeneous materials under complex load conditions. It has significant advantages in t...

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Problems solved by technology

[0003] However, since the tip of the diffuse crack cannot be precisely located, the existing fracture phase field method is difficult to effectively extract the parameters of the mixed diffuse crack tip under complex load conditions. Therefore, it is urgent to propose a method that can effectively extract the mixed type Numerical method for diffuse crack tip parameters

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