Abstract

In this article, a new fracture criterion for a mixed-type crack (type I + type II) is proposed. It is based on the assumption that the maximum tangential stresses in the prefracture region are equal to the local strength of the material. In this case, the size of the prefracture area and the local strength are determined taking into account nonsingular Т_хx and Т_zz stresses included in the expansion of the Williams stress function. The use of Т_хx and Т_zz stresses in the calculations allows one to describe the two-dimensional local constraint of the deformation along the crack front in three-dimensional bodies. In addition to K_I and K_II, the expression for the effective stress intensity factor (SIF) includes the ratios of the Т_хx and Т_zz stresses to the yield strength. This makes it possible to take into account the constraint of deformations in the transverse and longitudinal directions of the crack front, respectively. An example of the implementation of the developed criterion in relation to the determination of the fracture load of a tensile-stressed plate with a through inclined crack is given. Dependences of the Т_xx and Т_zz stresses on the plate thickness are presented for various crack slopes and plate thicknesses. It is shown that an increase in the plate thickness and a decrease in the crack slope lead to a decrease in the fracture load.

中文翻译：

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考虑混合型裂纹前端二维变形约束的二参数断裂准则

摘要

_{хx< /span>} 针对各种裂纹斜率和板厚度，给出了板厚度上的应力。结果表明，板厚的增加和裂纹斜率的减小会导致断裂载荷的减小。Т 和 _xxТ 应力影响屈服强度。这使得可以分别考虑裂纹前沿横向和纵向上的变形约束。给出了与确定具有贯穿倾斜裂纹的拉应力板的断裂载荷相关的所开发标准的实施示例。 _zzТ 和 Т，有效应力强度因子（SIF）的表达式包括_IIK和_IK 应力允许人们描述三维物体中沿裂纹前沿变形的二维局部约束。除了Т 和 _хxТ 应力包含在 Williams 应力函数的展开式中。 _zzТ 和_хxТ