Quantitative Analysis on the Major Factors in Measuring Pipeline Stress by Ultrasonic Method
-
摘要: 超声法是无损检测在役油气管道受力状态的有效方法，能够准确测出管道危险点的应力值，对判断变形管段是否处于安全状态有重大的工程意义。超声法属于敏感性测试技术，其影响因素主要有温度和管道曲面。基于声弹性效应，理论上分析了温度对零应力试件下LCR波（临界折射纵波）飞行时间t0的影响机理，并推导出修正公式；分析了管道曲面耦合状态对测量结果的影响，提出了根据管道曲率半径修正应力系数的方法。利用自主开发的超声应力测量装置，通过变温试验和管道打压试验来验证修正方法。结果显示：零应力试件下LCR波飞行时间与温度关系的理论推导公式和试验拟合公式有很好的一致性；超声法所测环向应力值修正后与应变法测量值在结果和分布规律上都一致。结果可为使用超声法高精度地测试管道应力提供有效的支撑。Abstract: Ultrasonic method, an effective way to measure on-line stress on oil and gas pipelines in nondestructive testing field, can take an accurate measurement of stress on the dangerous point. It has a significant influence on the safety of operating of deformed pipe sections. The accuracy of ultrasonic method, a kind of sensitivity testing techniques, is mainly affected by ambient temperature and the curvature of pipelines. Based on acoustic elastic theory, we first analyze the influence of temperature on LCR time-of-flight t0 in free stress specimens and propose modified formulas. Then, the influence of the curved surface coupling state on the measurement is analyzed and the method of stress coefficient correction based on radius of curvature of pipeline is proposed. The theoretic correction model has been verified by temperature and pipe pressing varying experiments on an independently developed experimental platform of LCR waves stress measurement. The results show that the theoretically deduced formula of the relationships between the time of flight of LCR waves and temperature are basically consistent with the experimental fitting formula of that in stress-free specimens. In terms of result and distribution trend of measured circumferential stress value, ultrasonic method is consistent with strain method after stress coefficient is corrected based on radius of curvature of pipes. The findings in this paper effectively improve the accuracy and reliability of ultrasonic method of measuring pipe stress.
-
-
[1] ZEYNALOVA M H, RUSTAMOV R B, SALAHOVA S E. Advanced space technology for oil spill detection[M]. Berlin:Springer Netherlands, 2009:99-120.
[2] SCHAJER G S. Encyclopedia of thermal stresses[M]. Berlin:Springer Netherlands, 2014:2280-2293.
[3] MACH J C, BUDROW C J, PAGAN D C, et al. Validating a model for welding induced residual stress using high-energy X-ray diffraction[J]. The Journal of the Minerals, Metals & Materials Society, 2017, 69(5):893-899.
[4] FILINOV V V, KUZNETSOV A N, ARAKELOV P G. Monitoring stressed state of pipelines by magnetic parameters of metal[J]. Russian Journal of Nondestructive Testing, 2017, 53(1):51-61.
[5] ÖRS T, GOURAUD F, GUINEBRETIÈRE R, et al. Neutron diffraction measurements of residual stress distribution in large zirconia based refractory bricks produced by electro-fusion and casting[J]. Journal of the European Ceramic Society, 2017, 37(5):2295-2302.
[6] ROSSINI N S, DASSISTI M, BENYOUNIS K Y, et al. Methods of measuring residual stresses in components[J]. Materials & Design, 2012, 35:572-588.
[7] LEON SALAMANCA T, BRAY D F. Residual stress measurement in steel plates and welds using critically refracted longitudinal (LCR) waves[J]. Research in Nondestructive Evaluation, 1996, 7(4):169-184.
[8] BRAY D E. Ultrasonic stress measurement using the critically refracted longitudinal (LCR) ultrasonic technique:US, US 6424922 B1[P]. 1999-01-19.
[9] JAVADI Y, PIRZAMAN H S, RAEISI M H, et al. Ultrasonic inspection of a welded stainless steel pipe to evaluate residual stresses through thickness[J]. Materials & Design, 2013, 49:591-601.
[10] 徐春广, 宋文涛, 潘勤学,等. 残余应力的超声检测方法[J]. 无损检测, 2014, 36(7):25-31. [11] 马子奇. 基于临界折射纵波声弹效应的平面应力测量理论和方法[D]. 哈尔滨:哈尔滨工业大学, 2014. [12] 宋文涛. 残余应力超声无损检测与调控技术研究[D]. 北京:北京理工大学, 2016. [13] EGLE D M, BRAY D E. Measurement of acoustoelastic and third-order elastic constants for rail steel[J]. Journal of the Acoustical Society of America, 1998, 59(3):741-744.
[14] ROSE J L. Ultrasonic guided waves in solid media[M]. Cambridge:Cambridge University Press, 2014.
[15] 吕干霖, 褚梅娟, 王斌修,等. 高温钢声速与声速滞后现象[J]. 声学学报, 1992(6):446-450. [16] 江泽涛. 温度对超声波波速及应力测量的影响[J]. 无损检测, 1999(6):245-248. [17] 徐志东, 范子亮. 金属材料的弹性模量随温度变化规律的唯象解释[J]. 西南交通大学学报, 1993, 28(2):87-92. [18] 陈宇帆, 王世杰, 贺寅彪,等. 密度随温度变化对反应堆压力容器热冲击的影响[J]. 压力容器, 2016, 33(7):18-24.
计量
- 文章访问数: 12
- HTML全文浏览量: 0
- PDF下载量: 5
下载:
