三维椭球形缺陷启裂载荷随倾角和压缩度变化的规律

本文基于扩展有限元法模拟不同尺寸和倾角三维椭球形缺陷的启裂行为，随后引入压缩度描述缺陷扁平程度，最后讨论缺陷倾角和压缩度对其启裂载荷的影响。结果表明：当缺陷形状呈扁椭球形时，随倾角(缺陷倾向与力方向的夹角)增加，启裂载荷先减小后增加。当缺陷形状呈近球形时，启裂载荷随倾角增加变化轻微。当缺陷倾角为0°时，其启裂载荷随压缩度增加先减小后增加。当倾角为15°，30°，45°，60°和75°时，启裂载荷随压缩度增加而减小。

VARIATION IN CRACK INITIATION LOAD OF THE THREE-DIMENSIONAL ELLIPSOIDAL FLAW WITH INCLINATION ANGLE AND COMPRESSIBILITY

In the present study, the cracking behavior of three-dimensional ellipsoidal flaws with different sizes and inclination angles (the angle between the loading direction and the tilting direction of the flaw) was simulated based on the extended finite element method. Subsequently, compressibility was introduced to describe the degree of the oblateness of the three-dimensional flaw. Finally, the effects of the compressibility and inclination angle of the three-dimensional flaw on the crack initiation load of the model were discussed. The results show that for the flat ellipsoid flaw models, the crack initiation load decreases and then increases as the inclination angle increases from 0° to 75°. For the sphere-like flaws, the crack initiation load changes slightly with the increase in the inclination angle. The crack initiation load decreases and then increases as the compressibility increases when the inclination angle of the flaw is 0°. As the inclination angle increases to 15°, 30°, 45°, 60° and 75°, the crack initiation load decreases as the compressibility increases.