基于试验数据的疲劳裂纹扩展门槛值研究  

STUDY OF FATIGUE CRACK GROWTH THRESHOLD BASED ON TEST RESULTS

作　　者：朱明亮[1] 轩福贞[1] 梅林波[2] 王思玉[2] 

机构地区：[1]华东理工大学机械与动力工程学院,上海200237 [2]上海汽轮机有限公司,上海200240

出　　处：《机械强度》2010年第5期805-809,共5页Journal of Mechanical Strength

基　　金：国家863高技术资助项目(2006AA04Z413);教育部新世纪优秀人才计划项目(NCET-06-0404)资助~~

摘　　要：试验确定门槛值是最常用和最基本的方法,裂纹闭合使其准确性受到质疑。文中总结基于试验数据确定门槛值的方法,依据高低压一体化转子材料的疲劳门槛值试验和疲劳裂纹稳定扩展数据,对不同确定方法进行比较。结果发现高压端(high-pressure zone,HP)门槛值比低压端(low-pressure zone,LP)大,最大载荷法、简易方法和近似公式确定的门槛值偏大,而由Paris公式直接外推所得门槛值过小,近似公式计算的门槛值准确性不高。通过分析晶粒尺寸对裂纹扩展路径的影响,认为高压端与低压端门槛值不同是由于裂纹闭合程度不同引起的,粗糙度诱发裂纹闭合占主导作用。The threshold of fatigue crack growth is commonly determined in terms of test results.However,the value of threshold is very difficult to extract owing to the effect of crack closure mechanism.In this report,the existing methods for determination of the fatigue crack growth threshold were reviewed.And then,the comparison was conducted among thresholds from the existing methods in terms of test data from high-low pressure combined rotor materials.Results show that the threshold of the high-pressure(HP) zone ...

关 键 词：门槛值 疲劳裂纹扩展 裂纹闭合 小裂纹 

分 类 号：TG111.8[金属学及工艺—物理冶金]