A full-field residual stress estimation scheme for fitness-for-service assessment of pipe girth welds: Part I – Identification of key parameters

2015 ◽  
Vol 126-127 ◽  
pp. 58-70 ◽  
Author(s):  
Shaopin Song ◽  
Pingsha Dong ◽  
Xianjun Pei
Keyword(s):  
Residual Stress ◽  
Full Field ◽  
Estimation Scheme ◽  
Stress Estimation ◽  
Girth Welds

Assessment of Residual Stress Profiles for Fitness for Service Assessment of Pipe Girth Welds

2014 ◽  
Author(s):  
Pingsha Dong ◽  
Shaopin Song ◽  
Jinmiao Zhang
Keyword(s):  
Residual Stress ◽  
Finite Element ◽  
Solution Procedure ◽  
Stress Profile ◽  
Full Field ◽  
Residual Stress Profile ◽  
Estimation Scheme ◽  
Detailed Assessment ◽  
Stress Profiles ◽  
Girth Welds

This paper aims to provide a detailed assessment of some of the existing residual stress profiles prescribed in widely used fitness-for-service assessment codes and standards, such as BS 7910 Appendix Q, by taking advantage of some comprehensive residual studies that become available recently. After presenting a case study on which residual stress measurements are available for validating finite element based residual stress solution procedure, residual stress profiles stipulated in BS 7910 for girth welds are evaluated in the context of a series of parametric finite element results and a shell theory based full-field residual stress estimation scheme. As a result, a number of areas for improvement in residual stress profile development are identified, including some specific considerations on how to attain some of these improvements.

A Full-Field Residual Stress Profile Estimation Scheme for Pipe Girth Welds

2012 ◽  
Author(s):  
Shaopin Song ◽  
Pingsha Dong ◽  
Jinmiao Zhang
Keyword(s):  
Residual Stress ◽  
Stress Distribution ◽  
Residual Stress Distribution ◽  
Stress Profile ◽  
Distribution Characteristics ◽  
Full Field ◽  
Residual Stress Profile ◽  
Weld Toe ◽  
Estimation Scheme ◽  
Girth Welds

For supporting fitness-for-service (FFS) assessment, this paper presents a method for providing a full field description of through-thickness residual stress profiles for pipe girth welds, beyond weld locations (e.g., at weld centerline and weld toe). The paper starts with a brief introduction of the finite element modeling procedure used in this study. Experimental validations are performed for a pipe weld geometry on which detailed experimental data have recently become available in the literature. Then, a large number of parametric residual stress analyses are performed to identify key parameters that govern through-thickness residual stress distribution characteristics. These parameters are not only shown to uniquely contribute to some of the important residual stress distribution characteristics of interest to FFS, but also can be formulated, to the first approximation, using basic mechanics and physics principle. Finally, a detailed application of the proposed full field residual stress estimation scheme is illustrated for various girth weld conditions.

Residual stress estimation of a silicon carbide-Kovar joint

1991 ◽  
Vol 26 (11) ◽  
pp. 2887-2892 ◽  
Author(s):  
Toshihiro Yamada ◽  
Motohiro Satoh ◽  
Akiomi Kohno ◽  
Kazuaki Yokoi
Keyword(s):  
Residual Stress ◽  
Silicon Carbide ◽  
Stress Estimation

scholarly journals Residual Stress State of X65 Pipeline Girth Welds Before and After Local and Furnace Post Weld Heat Treatment

2017 ◽  
Vol 139 (4) ◽  
Author(s):  
Yao Ren ◽  
Anna Paradowska ◽  
Bin Wang ◽  
Elvin Eren ◽  
Yin Jin Janin
Keyword(s):  
Heat Treatment ◽  
Residual Stress ◽  
Residual Stresses ◽  
Outer Surface ◽  
Post Weld Heat Treatment ◽  
Pipe Length ◽  
Stress Profiles ◽  
Girth Welds ◽  
Welded Pipe ◽  
Weld Heat

This research investigated the effects of global (in other words, furnace-based) and local post weld heat treatment (PWHT) on residual stress (RS) relaxation in API 5L X65 pipe girth welds. All pipe spools were fabricated using identical pipeline production procedures for manufacturing multipass narrow gap welds. Nondestructive neutron diffraction (ND) strain scanning was carried out on girth welded pipe spools and strain-free comb samples for the determination of the lattice spacing. All residual stress measurements were carried out at the KOWARI strain scanning instrument at the Australian Nuclear Science and Technology Organization (ANSTO). Residual stresses were measured on two pipe spools in as-welded condition and two pipe spools after local and furnace PWHT. Measurements were conducted through the thickness in the weld material and adjacent parent metal starting from the weld toes. Besides, three line-scans along pipe length were made 3 mm below outer surface, at pipe wall midthickness, and 3 mm above the inner surface. PWHT was carried out for stress relief; one pipe was conventionally heat treated entirely in an enclosed furnace, and the other was locally heated by a flexible ceramic heating pad. Residual stresses measured after PWHT were at exactly the same locations as those in as-welded condition. Residual stress states of the pipe spools in as-welded condition and after PWHT were compared, and the results were presented in full stress maps. Additionally, through-thickness residual stress profiles and the results of one line scan (3 mm below outer surface) were compared with the respective residual stress profiles advised in British Standard BS 7910 “Guide to methods for assessing the acceptability of flaws in metallic structures” and the UK nuclear industry's R6 procedure. The residual stress profiles in as-welded condition were similar. With the given parameters, local PWHT has effectively reduced residual stresses in the pipe spool to such a level that it prompted the thought that local PWHT can be considered a substitute for global PWHT.

scholarly journals Feasibility of Residual Stress Nondestructive Estimation Using the Nonlinear Property of Critical Refraction Longitudinal Wave

2017 ◽  
Vol 2017 ◽  
pp. 1-11
Author(s):  
Yu-Hua Zhang ◽  
Xin-Xin Li ◽  
Xiang-Hong Wang ◽  
Zhen-Feng Huang ◽  
Han-Ling Mao ◽  
...  
Keyword(s):  
Residual Stress ◽  
Stress State ◽  
Wave Velocity ◽  
Nonlinear Coefficient ◽  
Quantitative Information ◽  
Difficult Problem ◽  
Nonlinear Property ◽  
Deformation State ◽  
Stress Estimation ◽  
Nondestructive Estimation

Residual stress has significant influence on the performance of mechanical components, and the nondestructive estimation of residual stress is always a difficult problem. This study applies the relative nonlinear coefficient of critical refraction longitudinal (LCR) wave to nondestructively characterize the stress state of materials; the feasibility of residual stress estimation using the nonlinear property of LCR wave is verified. The nonlinear ultrasonic measurements based on LCR wave are conducted on components with known stress state to calculate the relative nonlinear coefficient. Experimental results indicate that the relative nonlinear coefficient monotonically increases with prestress and the increment of relative nonlinear coefficient is about 80%, while the wave velocity only decreases about 0.2%. The sensitivity of the relative nonlinear coefficient for stress is much higher than wave velocity. Furthermore, the dependence between the relative nonlinear coefficient and deformation state of components is found. The stress detection resolution based on the nonlinear property of LCR wave is 10 MPa, which has higher resolution than wave velocity. These results demonstrate that the nonlinear property of LCR wave is more suitable for stress characterization than wave velocity, and this quantitative information could be used for residual stress estimation.

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