TDFAD APPROACH TO HIGH TEMPERATURE DEFECT ASSESSMENT AND ITS ENGINEERING APPLICATION  

作　　者：XuanFuzhen TuShandong WangZhengdong 

机构地区：[1]DepartmentofMechanicalEngineenng,EastChinaUniversityofScienceandTechnology,Shanghai200237,China

出　　处：《Chinese Journal of Mechanical Engineering》2004年第4期537-542,共6页中国机械工程学报（英文版）

基　　金：ThisprojectissupportedbyNationalNaturalScienceFoundationofChina(No.50225517)NaturalScienceFoundationofShanghai,China(No.03ZR14022).

摘　　要：From the idea of failure of defective structures at high temperature beingcontrolled by two mechanisms: fast fracture due to creep crack growth initiating at the crack tipand creep rupture on the weakened section, a time-dependent failure assessment diagram (TDFAD) isdeveloped on the basis of the time dependent crack tip parameter J integral. According to theproposed TDFAD method, detailed crack initiation and creep crack growth analysis is avoided insafety assessments of high temperature structures by performing simple calculations of stressintensity factor and limit load. To evaluate the creep toughness parameter K_(mat), three differentexpressions are suggested on the basis of experimental load-line displacement, creep crackinitiation and growth parameters as well as the isochronous stress-strain curve. The influence ofservice factors such as temperature and service-time on the proposed TDFAD is discussed by using theproperties of 2.25CrlMo steel and an example is also presented to illustrate the approach.From the idea of failure of defective structures at high temperature beingcontrolled by two mechanisms: fast fracture due to creep crack growth initiating at the crack tipand creep rupture on the weakened section, a time-dependent failure assessment diagram (TDFAD) isdeveloped on the basis of the time dependent crack tip parameter J integral. According to theproposed TDFAD method, detailed crack initiation and creep crack growth analysis is avoided insafety assessments of high temperature structures by performing simple calculations of stressintensity factor and limit load. To evaluate the creep toughness parameter K_(mat), three differentexpressions are suggested on the basis of experimental load-line displacement, creep crackinitiation and growth parameters as well as the isochronous stress-strain curve. The influence ofservice factors such as temperature and service-time on the proposed TDFAD is discussed by using theproperties of 2.25CrlMo steel and an example is also presented to illustrate the approach.

关 键 词：Defective structure Safety assessment CREEP High temperature Time-dependent failure assessment diagram 

分 类 号：TG111.2[金属学及工艺—物理冶金] TG111.8[金属学及工艺—金属学]