Engineering Estimation Method of Creep Fracture Parameter C for Axial Internal Surface Cracked Pipes under Internal Pressure
-
摘要: 以内压条件下含轴向内表面裂纹的管道为研究对象，通过引入x0参数使J积分全塑性解与蠕变指数无关对Zahoor提出的蠕变断裂参数C*估算方法进行改进；采用改进方法、Zahoor估算公式以及参考应力法中的R6整体解和Kim优化解计算不同蠕变指数和不同裂纹尺寸下的C*值，并与有限元计算结果进行比较。结果表明：参考应力法所得C*值比有限元计算结果大2～8倍，准确度较差；改进方法所得C*值与有限元计算结果的比值在1左右，准确度较高；与Zahoor估算公式相比，改进方法在蠕变指数为3时的计算准确度更高，但随着蠕变指数增大， 2种方法的计算准确度趋于相同。Abstract: With axial internal surface cracked pipes under internal pressures as the research object, the creep fracture parameter C* estimation method proposed by Zahoor was improved by introducing the x0 parameter to make the J-integral full plastic solution independent of Norton indexes.The C* values under the conditions of different Norton indexes and different crack size were calculated by the improved method, Zahoor solution, and reference stress methods including R6 global solution and Kim solution, and were compared with the finite element calculation.The results show that the C* values calculated by the reference stress methods were two to eight times higher than those by the finite element calculation; the accuracy of the reference stress methods was poor.The ratios of the C* values calculated by the improved method to the finite element calculation results were close to 1; the accuracy of the improved method was relatively high.Comparing with the Zahoor solution, the improved method had higher calculation accuracy with the Norton index of 3.But as the Norton index increased, the calculation accuracy of the two methods tended to be the same.
-
-
[1] HARPER M P,ELLISON E G.The use of the C* parameter in predicting creep crack propagation rates[J].The Journal of Strain Analysis for Engineering Design,1977,12(3):167-179.
[2] GOODALL I W,AINSWORTH R A.An assessment procedure for the high temperature response of structures[M]//Creep in Structures.Heidelberg:Springer, 1991:303-311.
[3] WANG K,WANG G Z,TAN X M,et al.Creep fracture parameter C* solutions for axial internal and external surface cracks in pressurized cylinders[J].Engineering Fracture Mechanics,2020,231:107026.
[4] 张婷.基于参考应力法的均质拉伸试样高温蠕变断裂参量特性研究[D].南昌:南昌大学,2010. ZHANG T.Study on high temperature creep fracture mechanics parameter of homogeneous tension specimen based on reference stress method[D].Nanchang:Nanchang University,2010.
[5] YATOMI M.Comparison among estimation methods of C* parameter for axially oriented external surface crack in cylinders[J].Materials at High Temperatures,2015,32(5):468-474.
[6] LANDES J D,BEGLEY J A.A fracture mechanics approach to creep crack growth[M]//Mechanics of Crack Growth.West Conshohocken,PA:ASTM International,1976:128-148.
[7] KUMAR V,GERMAN M D,SHIH C F.Engineering approach for elastic-plastic fracture analysis[R].[S.l.]:Office of Scientific and Technical Information (OSTI),1981.
[8] YOON K K,KILLIAN D E.J estimation method for a semi-elliptical surface flaw in a cylinder[J].Journal of Pressure Vessel Technology,1995,117(1):66-70.
[9] BONG YOON K,GYU PARK T,SAXENA A.Creep crack growth analysis of elliptic surface cracks in pressure vessels[J].International Journal of Pressure Vessels and Piping,2003,80(7/8):465-479.
[10] ZAHOOR A.Ductile Fracture Handbook:(in Three Volumes):Research Project 1757-69 [M].[S.l.]:Electric Power Research Institute, 1989.
[11] YAGAWA G,KITAJIMA Y,UEDA H.Three-dimensional fully plastic solutions for semi-elliptical surface cracks[J].International Journal of Pressure Vessels and Piping,1993,53(3):457-510.
[12] 孙春燕.内压条件下含轴向裂纹管道蠕变断裂参量C*计算方法研究[D].上海:华东理工大学,2015. SUN C Y.Study on calculation method of creep fracture parameters C*for finite internal axial surface cracks in cylinders[D].Shanghai:East China University of Science and Technology,2015.
[13] 孙亮,李培宁.等效原场应力J积分工程估算法[C]//第五届全国压力容器学术会议论文集.南京:中国机械工程学会压力容器分会,2001:238-242. SUN L, LI P N.J estimation method for equivalent primary field stress [C]//Proceedings of the 5th National Conference on Pressure Vessels.Nanjing:Pressure Vessel Branch of Chinese Mechanical Engineering Society, 2001:238-242.
[14] SI J,XUAN F Z,TU S T.A numerical creep analysis on the interaction of twin semi-elliptical cracks[J].International Journal of Pressure Vessels and Piping,2008,85(7):459-467.
[15] 郑津洋, 董其伍, 桑芝富.过程设计[M].北京:化学工业出版社, 2003. ZHENG J Y,DONG Q W,SANG Z F.Process design[M].Beijing:Chemical Industry Press,2003.
计量
- 文章访问数: 13
- HTML全文浏览量: 0
- PDF下载量: 2
下载:
