疲劳裂纹扩展的非比例过载效应  

EFFECT OF NON-PROPORTIONAL OVERLOADINGON FATIGUE CRACK GROWTH

作　　者：高桦[1] 陈友萱[2] 李明[2] 陈德海 

机构地区：[1]上海工程技术大学材料系,副教授上海200051 [2]上海工程技术大学 [3]上海大隆机器厂

出　　处：《金属学报》1990年第4期A296-A302,共7页Acta Metallurgica Sinica

摘　　要：本工作研究了比例(Ⅰ型)过载及非比例(复合型)过载对常幅Ⅰ型疲劳裂纹扩展的影响。结果表明:Ⅰ型过载所引起的裂纹滞后扩展效应远较复合型为强。因此,在估算疲劳寿命时将零、构件实际承受的过载(大都为非比例过载)简单地当作比例过载处理,可能会过高地估计寿命,带来不安全因素。文章从Ⅰ型及复合型过载所引起的裂纹钝化、裂端塑性区的形状、尺寸及裂纹闭合等方面讨论了它们对裂纹扩展滞后效应的影响。The effects of proportional and non-proportional overloading on modeⅠ fatigue crack growth have been studied, and the influences of crack tip plasticzone, crack tip blunting as well as crack closure were discussed. The proportional(mode Ⅰ) overloading may cause more serious crack growth retardation than non-proportional (mixed mode) overloading. Therefore, for estimating fatigue life ofengineering structures to simplify a real overload which may often be non-propor-tional as a proportional one is not always safe.

关 键 词：40CR钢 疲劳 裂纹 扩展 非比例 

分 类 号：TG142.15[一般工业技术—材料科学与工程]