表面粗糙度对表面应力集中系数影响的定量分析-6

表面粗糙度对表面应力集中系数和疲劳寿命影响分析 Effect of Roughness on Surface Stress Concentration Factor

and Fatigue Life

章刚 刘军 刘永寿 岳珠峰

（ 西北工业大学 工程力学系，西安 710072）

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*

ZHANG Gang LIU Jun LIU YongShou YUE Zhufeng

(Department of Mechanics, Northwestern Polytechnical University, Xi’an 710072, China)

摘要 把平板的表面形貌简化为半椭圆形微缺口，采用有限元法对不同表面粗糙度下应

力场进行分析，以得到不同表面粗糙度Rz时平板的表面应力集中系数, 并预测出不同表面粗糙度的平板在不同存活率下的疲劳寿命，讨论表面粗糙度对疲劳寿命的影响。采用回归方法建立了表面应力集中系数与微缺口中心间距、表面粗糙度之间的经验公式。结果表明，在相同存活率下，表面粗糙度与平板的对数疲劳寿命呈二次曲线关系。

关键词 表面粗糙度 微缺口 有限元 应力集中系数 疲劳寿命

中图分类号 V215.52 O346.23

Abstract The surface topography of plate was simplified as micro semi-ellipse notches.

Finite element method was used to analyze the stress field of the plate with different roughness and obtain the effect of roughness on surface stress concentration factor. Fatigue life of the plate was predicted with given survivability and the effect of roughness on fatigue life was discussed. Empirical equation that relates distance between notches and roughness to stress concentration factor was established by linear regression method. An approximate quadratic curve has been found to suit the relationship between the roughness and logarithmic fatigue lives plate with given survivability.

Key words Roughness; Micro-notch; Finite Element; Stress Concentration Factor; Fatigue life

Corresponding author: ZHANG Gang, E-mail:zg4117@163.com, Tel:/Fax:+86-2988495540 The project supported by the National Science Foundation of China (No.10472094) Manuscript received 2007.

*收稿日期2007，国家自然科学基金资助项目（10472094）。

**章刚，男，1985年3月生，湖北宜都人，汉族。西北工业大学在读硕士研究生，研究方向为固体力学材料力学行为与计算机模拟。通信地址：西北工业大学410信箱。