新的估算表面裂纹应力强度因子经验公式

NEW EMPIRICAL STRESS-INTENSITY-FACTOR EQUATIONS FOR SURFACE CRACKS

该文给出了新的估算拉伸和纯弯曲载荷下表面裂纹应力强度因子的经验公式。根据疲劳裂纹扩展的数值模拟结果确定强度因子分布函数;利用按已知应力强度因子分布函数求裂纹形状及相应应力强度因子的方法计算给定尺寸的表面裂纹的应力强度因子;通过对数值结果的曲线回归得到估算表面裂纹应力强度因子经验公式。利用该公式对有限厚度和宽度平板内表面裂纹的应力强度因子进行了估算,并与已知的半椭圆形表面裂纹的应力强度因子解进行了比较。该文结果为估算表面裂纹应力强度因子提供了一种新的途径。

This paper presents the new empirical formulas of stress-intensity-factor （SIF） for surface cracks due to tension and pure bending loads. A SIF distribution function is chosen based on the numerical results obtained by simulating the fatigue crack growth and the SIF and shape for a surface crack of given dimensions is obtained using the method. Such empirical formulas of SIF for surface cracks are obtained by curve fitting to the numerical results. Predictions of SIF for surface cracks in plates of finite width and thickness are made using the empirical formulas, and comparisons with the known solutions of semi-ellipse surface cracks are presented. The results obtained in this paper are considered to be an alternative to the evaluation of SIFs for surface cracks.