Abstract

In this article, a new fracture criterion is formulated for a normal rupture crack, the most common in practice, based on the assumption that the tangential stresses in the prefracture zone 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 the nonsingular Т_хx and Т_zz stresses included in the asymptotic stress distribution according to Williams and characterizing the two-dimensional local constraint of deformation along the crack front in three-dimensional bodies. An expression for the effective stress intensity factor is obtained. In addition to the classical stress intensity factor, it includes the ratios of the Т_xx and Т_zz stresses to the yield strength. This makes it possible to take into account the restriction of deformations in the transverse (due to Т_xx stresses) and longitudinal (due to Т_zz stresses) directions in the vicinity of the crack front. Verification of the developed software tools and the proposed fracture criterion has been carried out. Examples of the implementation of the developed criterion for assessing crack resistance of a plate stretched in one or two directions with a coaxial transverse crack are given.

中文翻译：

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沿正向断裂裂纹前端变形双轴约束的断裂准则

摘要

在本文中，基于预断裂区的切向应力等于材料的局部强度的假设，针对实际中最常见的正向断裂裂纹制定了新的断裂准则。在这种情况下，根据威廉姆斯的渐进应力分布中包含的非奇异Т _хx和Т _zz应力，并描述沿裂纹前沿变形的二维局部约束，确定预断裂区域的大小和局部强度。在三维物体中。获得有效应力强度因子的表达式。除了经典的应力强度因子之外，它还包括Т _xx的比率Т _zz应力为屈服强度。这样就可以考虑裂纹前沿附近横向（由于Т _xx应力）和纵向（由于Т _zz应力）变形的限制。已对开发的软件工具和提出的断裂准则进行了验证。给出了实施所制定标准的示例，用于评估具有同轴横向裂纹的沿一个或两个方向拉伸的板材的抗裂性。